US20220304856A1 - Intraocular shunt implantation - Google Patents

Abstract

Glaucoma can be treated by implanting an intraocular shunt in the eye. The implantation can be performed by first determining an entry area below a corneal limbus of an eye. Thereafter, the intraocular shunt can be inserted into eye tissue through the entry area such that an inflow end of the shunt is positioned in the anterior chamber of the eye and an outflow end of the shunt is positioned between layers of Tenon's capsule.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation application of U.S. patent application Ser. No. 16/509,458, filed on Jul. 11, 2019, which is a continuation application of U.S. patent application Ser. No. 15/703,802, filed on Sep. 13, 2017, now U.S. Pat. No. 10,369,048, which is a continuation application of U.S. patent application Ser. No. 14/317,676, filed on Jun. 27, 2014, now U.S. Pat. No. 9,808,373, which claims the priority benefit of U.S. Provisional Application No. 61/841,224, filed on Jun. 28, 2013, and U.S. Provisional Application No. 61/895,341, filed on Oct. 24, 2013, the entirety of each of which is incorporated herein by reference.
BACKGROUNDField of the Inventions
• The present disclosure generally relates to devices and methods of implanting an intraocular shunt into an eye.
Description of the Related Art
• Glaucoma is a disease in which the optic nerve is damaged, leading to progressive, irreversible loss of vision. It is typically associated with increased pressure of the fluid (i.e., aqueous humor) in the eye. Untreated glaucoma leads to permanent damage of the optic nerve and resultant visual field loss, which can progress to blindness. Once lost, this damaged visual field cannot be recovered. Glaucoma is the second leading cause of blindness in the world, affecting 1 in 200 people under the age of fifty, and 1 in 10 over the age of eighty for a total of approximately 70 million people worldwide.
• The importance of lowering intraocular pressure (IOP) in delaying glaucomatous progression has been well documented. When drug therapy fails, or is not tolerated, surgical intervention is warranted. Surgical filtration methods for lowering intraocular pressure by creating a fluid flow-path between the anterior chamber and an area of lower pressure have been described. Intraocular shunts can be positioned in the eye to drain fluid from the anterior chamber to locations such as the sub-Tenon's space, the subconjunctival space, the episcleral vein, the suprachoroidal space, Schlemm's canal, and the intrascleral space.
• Positioning of an intraocular shunt to drain fluid into the intrascleral space is promising because it avoids contact with the conjunctiva and the supra-choroidal space. Avoiding contact with the conjunctiva and supra-choroid is important because it reduces irritation, inflammation and tissue reaction that can lead to fibrosis and reduce the outflow potential of the subconjunctival and suprachoroidal space. The conjunctiva itself plays a critical role in glaucoma filtration surgery. A less irritated and healthy conjunctiva allows drainage channels to form and less opportunity for inflammation and scar tissue formation. Intrascleral shunt placement safeguards the integrity of the conjunctiva and choroid, but may provide only limited outflow pathways that may affect the long term IOP lowering efficacy.
SUMMARY
• According to some embodiments, methods and devices are provided for positioning an intraocular shunt within the eye to treat glaucoma. Various methods are disclosed herein which allow a clinician to create a fluid pathway from the anterior chamber to an area of lower pressure within the eye. Although methods may be discussed in the context of positioning an outflow end of a shunt in a particular location (e.g., between layers of Tenon's capsule), the methods disclosed herein can be used to create a fluid pathway in which the outflow end of the shunt is positioned in other areas of low pressure, such as the supraciliary space, suprachoroidal space, the intrascleral space (i.e., between layers of sclera), intra-Tenon's adhesion space (i.e., between layers of Tenon's capsule), or subconjunctival space.
• For example, a method of treating glaucoma is disclosed that can comprise inserting an intraocular shunt into eye tissue such that an inflow end of the shunt is positioned in the anterior chamber of the eye and an outflow end of the shunt is positioned between layers of Tenon's capsule. The shunt can comprise a lumen that extends between the inflow and outflow ends and that is configured to permit flow of aqueous humor from the inflow end through the shunt to the outflow end.
• In accordance with some embodiments, the shunt can be introduced into the eye through the cornea. After introducing the shunt through the cornea, the shunt can be advanced into the sclera. For example, the shunt can be advanced into the sclera through the anterior chamber angle tissue.
• In some embodiments, the device comprises a shaft that can be advanced into the sclera until reaching and no further than a first position at which a bevel of the shaft is positioned between the layers of Tenon's capsule.
• In some embodiments, after the shaft is positioned within the sclera (e.g., after the shaft reaches the first position), a pusher component of the device can be advanced relative to the shaft such that the shunt is pushed distally out of the shaft. Although the entire shunt can be advanced out of the shaft by the pusher component, the method can be implemented such that less than an entire length of the shunt is pushed distally out of the shaft.
• The device can comprise a sleeve having a lumen and a distal end. The shaft can be received within the lumen of the sleeve.
• In some embodiments, after the shaft is positioned within the sclera (e.g., after the shaft reaches the first position), the pusher component can be advanced to a distalmost position at which a distal end of the pusher component is positioned longitudinally proximal to the sleeve distal end. Further, the pusher component can also be advanced to a distalmost position at which a distal end of the pusher component is positioned longitudinally adjacent to the sleeve distal end.
• Further, in some embodiments, the shaft can be positioned within the sclera (e.g., after the shaft reaches the first position) such that a distal end of the sleeve is spaced apart from the eye tissue. Once the shaft is in place, the pusher component can be advanced until a distal end of the pusher component is positioned longitudinally proximal to or adjacent to the sleeve distal end or the bevel. Furthermore, after the shunt has been at least partially advanced out of the bevel, the shaft can be proximally retracted into the sleeve. Proximal retraction of the shaft into the sleeve can be performed with the shaft maintaining its position relative to and within the sclera or with the sleeve maintaining its position relative to the sclera (whether spaced apart from the eye tissue or abutting the eye tissue), as discussed herein.
• Moreover, as noted herein, some embodiments of the methods can be performed whether the outflow end of the shunt is positioned between layers of Tenon's capsule or whether the outflow end of the shunt is positioned in another area of low pressure.
• For example, referring to embodiments in which the shunt outflow end is positioned between layers of Tenon's capsule, the device can be at the first position and a distal end of the sleeve can be spaced apart from the eye tissue, such as the anterior chamber angle tissue. Thereafter, while maintaining the position of the shaft relative to the sclera, the sleeve can be advanced distally over the shaft until the distal end of the sleeve contacts eye tissue, such as the anterior chamber angle tissue. After the sleeve distal end contacts the tissue, the shaft can be proximally withdrawn from the sclera until the bevel is received within a lumen of the sleeve. However, in some embodiments, the sleeve distal end can be maintained at a given position relative to the eye tissue (whether the sleeve distal end is spaced apart from or abutting the eye tissue) while the shaft is withdrawn into the sleeve.
• In some embodiments, a method of treating glaucoma is provided that can comprise inserting an intraocular shunt into eye tissue such that the shunt conducts fluid from the anterior chamber of the eye to a region between layers of Tenon's capsule. Further, in some embodiments, the method can comprise inserting an intraocular shunt into eye tissue such that the shunt conducts fluid from the anterior chamber of the eye to the intra-Tenon's adhesion space of the eye.
• The method can also be performed such that a hollow shaft is inserted into the eye through the cornea. The shaft can be configured to hold the shunt. For example, the shaft can be enter the eye through the cornea. The intra-Tenon's adhesion space can comprise a deep layer and a superficial layer, and an outflow end of the shunt can be positioned between the deep and superficial layers.
• Further, a bevel of a shaft can be advanced to a position between the deep and superficial layers, and while maintaining the bevel stationary relative to the eye tissue, the shunt can be distally advanced from the shaft into the intra-Tenon's adhesion space.
• In accordance with some embodiments, a method of treating glaucoma is disclosed that can comprise advancing a shaft of a device into eye tissue until a bevel of the shaft reaches a target area. Then, while maintaining the bevel substantially stationary relative to the target area, the sleeve of the device can be advanced distally over the shaft until a distal end of the sleeve contacts the eye tissue. Thereafter, upon contacting the sleeve distal end with the eye tissue, the shaft can be proximally withdrawn from the eye tissue.
• Additionally, while maintaining the bevel substantially stationary relative to the target area, a plunger can be advanced within the shaft to advance a shunt until the shunt extends into the target area. For example, less than an entire length of the shunt can be pushed distally out of the shaft. The plunger can be advanced until a distal end of the plunger is positioned longitudinally adjacent to the sleeve distal end. The shunt can be introduced into the eye through the cornea. The target area can be selected from supraciliary space, suprachoroidal space, a space between layers of sclera (i.e., intrascleral space), a space between layers of Tenon's capsule (i.e., intra-Tenon's adhesion space), or subconjunctival space. The sleeve can be advanced between about 1 mm to about 4 mm. Further, in some embodiments, the sleeve can be advanced between about 2 mm to about 3 mm.
• For example, in some embodiments, a method of deploying an intraocular shunt into an eye is provided. The method can comprise the steps of: inserting into the eye a hollow shaft configured to hold the intraocular shunt; and advancing the shunt from the hollow shaft such that the shunt forms a passage from the anterior chamber of the eye to the intra-Tenon's adhesion space of the eye.
• The inserting step can further comprise the step of injecting an aqueous solution into the eye. For example, the aqueous solution can be injected below Tenon's capsule. The inserting step can also comprise ab interno insertion of the hollow shaft into the eye. Ab interno insertion can comprise inserting the hollow shaft into the eye above the corneal limbus. Further, ab interno insertion can comprise inserting the hollow shaft into the eye below the corneal limbus.
• Additionally, some methods can comprise: inserting into the eye a hollow shaft configured to hold the intraocular shunt, a portion of the hollow shaft extending linearly along a longitudinal axis, and at least one other portion of the hollow shaft extending off the longitudinal axis; and advancing the shunt from the hollow shaft such that the shunt forms a passage from the anterior chamber of the eye to the intra-Tenon's adhesion space.
• In accordance with some embodiments, a method of treating glaucoma can also comprise inserting an intraocular shunt into eye tissue such that an inflow end of the shunt is positioned in the anterior chamber of the eye and an outflow end of the shunt is positioned between layers of Tenon's capsule. The layers of Tenon's capsule can comprise a deep layer and a superficial layer.
• Some embodiments of the methods disclosed herein such that the inserting step can further comprise the step of injecting an aqueous solution into the eye. For example, an aqueous solution can be injected below Tenon's capsule. The inserting step can also comprise ab interno insertion of the hollow shaft into the eye. Ab interno insertion can comprise inserting the hollow shaft into the eye above the corneal limbus. Ab interno insertion can comprise inserting the hollow shaft into the eye below the corneal limbus.
• Some embodiments of the methods disclosed herein can be implemented such that the inserting step comprises ab interno insertion of the hollow shaft into the eye.
• Some embodiments of the methods disclosed herein can be implemented such that the hollow shaft is inserted into the eye without removing an anatomical feature of the eye.
• The anatomical feature of the eye can be selected from the group consisting of: the trabecular meshwork, the iris, the cornea, and the aqueous humor. In accordance with some embodiments, the method can be performed without inducing subconjunctival blebbing or endophthalmitis.
• Additional features and advantages of the subject technology will be set forth in the description below, and in part will be apparent from the description, or may be learned by practice of the subject technology. The advantages of the subject technology will be realized and attained by the structure particularly pointed out in the written description and embodiments hereof as well as the appended drawings.
• It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the subject technology.
BRIEF DESCRIPTION OF THE DRAWINGS
• Various features of illustrative embodiments are described below with reference to the drawings. The illustrated embodiments are intended to illustrate, but not to limit, the inventions. The drawings contain the following figures:
• FIG. 1 provides a cross-sectional diagram of the general anatomy of the eye.
• FIG. 2 is an enlarged cross-sectional diagram of the eye taken along section lines2-2 ofFIG. 1.
• FIG. 3 depicts, implantation of an intraocular shunt with a distal end of a deployment device holding a shunt, shown in cross-section, according to some embodiments.
• FIG. 4 depicts an intraocular shunt at least partially disposed within a hollow shaft of a deployment device, according to some embodiments.
• FIG. 5 provides a schematic of a shunt having a flexible portion, according to some embodiments.
• FIGS. 6A-6C provide schematics of a shunt implanted into an eye for regulation of fluid flow from the anterior chamber of the eye to a drainage structure of the eye, according to some embodiments.
• FIG. 7A shows an embodiment of a shunt in which the proximal portion of the shunt includes more than one port and the distal portion of the shunt includes a single port.
• FIG. 7B shows another embodiment of a shunt in which the proximal portion includes a single port and the distal portion includes more than one port.
• FIG. 7C shows another embodiment of a shunt in which the proximal portions include more than one port and the distal portions include more than one port.
• FIGS. 8A-8B show different embodiments of multi-port shunts having different diameter ports.
• FIGS. 9A-9C provide schematics of shunts having a slit located along a portion of the length of the shunt, according to some embodiments.
• FIG. 10 depicts a shunt having multiple slits along a length of the shunt, according to some embodiments.
• FIG. 11 depicts a shunt having a slit at a proximal end of the shunt, according to some embodiments.
• FIG. 12 provides a schematic of a shunt that has a variable inner diameter, according to some embodiments.
• FIGS. 13A-13D depict a shunt having multiple prongs at a distal and/or proximal end, according to some embodiments.
• FIGS. 14A-14D depict a shunt having a longitudinal slit at a distal and/or proximal end, according to some embodiments.
• FIG. 15 is a schematic showing an embodiment of a shunt deployment device.
• FIG. 16 shows an exploded view of the device shown inFIG. 16.
• FIGS. 17A-17D are schematics showing different enlarged views of the deployment mechanism of the deployment device, according to some embodiments.
• FIGS. 18A-18C are schematics showing interaction of the deployment mechanism with a portion of the housing of the deployment device, according to some embodiments.
• FIG. 19 shows a cross-sectional view of the deployment mechanism of the deployment device, according to some embodiments.
• FIGS. 20A-20B show schematics of the deployment mechanism in a pre-deployment configuration, according to some embodiments.
• FIG. 20C shows an enlarged view of the distal portion of the deployment device ofFIG. 20A, with an intraocular shunt loaded within a hollow shaft of the deployment device, according to some embodiments.
• FIGS. 21A-21B show schematics of the deployment mechanism at the end of the first stage of deployment of the shunt from the deployment device, according to some embodiments.
• FIG. 21C shows an enlarged view of the distal portion of the deployment device ofFIG. 21A, with an intraocular shunt partially deployed from within a hollow shaft of the deployment device, according to some embodiments.
• FIG. 22A shows a schematic of the deployment device after deployment of the shunt from the device, according to some embodiments.
• FIG. 22B show a schematic of the deployment mechanism at the end of the second stage of deployment of the shunt from the deployment device, according to some embodiments.
• FIG. 22C shows an enlarged view of the distal portion of the deployment device after retraction of the shaft with the pusher abutting the shunt, according to some embodiments.
• FIG. 22D shows an enlarged view of the distal portion of the deployment device after deployment of the shunt, according to some embodiments.
• FIGS. 23-30 depict a sequence for ab interno shunt placement, according to some embodiments.
• FIG. 31 depicts an implanted shunt in an S-shaped scleral passageway, according to some embodiments.
• FIG. 32 depicts an example of a hollow shaft configured to hold an intraocular shunt fully within the shaft, according to some embodiments.
• FIGS. 33-39 depict a sequence for ab externo shunt placement, according to some embodiments.
• FIGS. 40-41 depict a sequence for ab externo insertion of a shaft of a deployment device using an applicator, according to some embodiments.
• FIG. 42 depicts deployment of the shunt in the intra scleral space where a distal end of the shunt is flush with the sclera surface, according to some embodiments.
• FIG. 43 depicts deployment of the shunt in the intra scleral space where a distal end of the shunt is about 200-500 micron behind the scleral exit, according to some embodiments.
• FIG. 44 depicts deployment of the shunt in the intra scleral space where a distal end of the shunt is more than about 500 micron behind the scleral exit, according to some embodiments.
• FIG. 45 depicts placement of a shunt in the supraciliary space, according to some embodiments.
• FIG. 46 depicts placement of a shunt in the suprachoroidal space, according to some embodiments.
• FIG. 47 depicts placement of a shunt in the subconjunctival space, according to some embodiments.
• FIG. 48 depicts placement of a shunt in the intrascleral space, according to some embodiments.
• FIG. 49 depicts placement of a shunt in the intra-Tenon's adhesion space, according to some embodiments.
• FIG. 50 is an enlarged schematic cross-sectional view taken alongsection50 ofFIG. 49.
• FIG. 51 is a perspective view taken along section lines51-51 ofFIG. 50.
• FIGS. 52A-52E depict an intraocular shunt being deployed within the eye, according to another embodiment.
• FIGS. 53A-53E depict an intraocular shunt being deployed within the eye, according to yet another embodiment.
• FIGS. 54A-54E depict an intraocular shunt being deployed within the eye, according to yet another embodiment.
DETAILED DESCRIPTION
• In the following detailed description, numerous specific details are set forth to provide a full understanding of the subject technology. It should be understood that the subject technology may be practiced without some of these specific details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the subject technology.
• Further, while the present description sets forth specific details of various embodiments, it will be appreciated that the description is illustrative only and should not be construed in any way as limiting. Additionally, it is contemplated that although some embodiments may be disclosed or shown in the context of ab interno procedures, such embodiments can be used in ab externo procedures. Furthermore, various applications of such embodiments and modifications thereto, which may occur to those who are skilled in the art, are also encompassed by the general concepts described herein.
• Glaucoma is a disease in which the optic nerve is damaged, leading to progressive, irreversible loss of vision. It is typically associated with increased pressure of the fluid (i.e., aqueous humor) in the eye. Untreated glaucoma leads to permanent damage of the optic nerve and resultant visual field loss, which can progress to blindness. Once lost, this damaged visual field cannot be recovered.
• In conditions of glaucoma, the pressure of the aqueous humor in the eye (anterior chamber) increases and this resultant increase of pressure can cause damage to the vascular system at the back of the eye and especially to the optic nerve. The treatment of glaucoma and other diseases that lead to elevated pressure in the anterior chamber involves relieving pressure within the anterior chamber to a normal level.
• Glaucoma filtration surgery is a surgical procedure typically used to treat glaucoma. The procedure involves placing a shunt in the eye to relieve intraocular pressure by creating a pathway for draining aqueous humor from the anterior chamber of the eye. The shunt is typically positioned in the eye such that it creates a drainage pathway between the anterior chamber of the eye and a region of lower pressure. Various structures and/or regions of the eye having lower pressure that have been targeted for aqueous humor drainage include Schlemm's canal, the subconjunctival space, the episcleral vein, the suprachoroidal space, or the subarachnoid space. Methods of implanting intraocular shunts are known in the art. Shunts may be implanted using an ab externo approach (entering through the conjunctiva and inwards through the sclera) or an ab interno approach (entering through the cornea, across the anterior chamber, through the trabecular meshwork and sclera).
• FIG. 1 provides a schematic diagram of the general anatomy of the eye. An anterior aspect of theanterior chamber1 of the eye is thecornea2, and a posterior aspect of theanterior chamber1 of the eye is theiris4. Beneath theiris4 is thelens5. Theanterior chamber1 is filled withaqueous humor3. Theaqueous humor3 drains into a space(s)6 deep to theconjunctiva7 through the trabecular meshwork (not shown in detail) of thesclera8. The aqueous humor is drained from the space(s)6 deep to theconjunctiva7 through a venous drainage system (not shown).
• FIG. 2 is an enlarged view of the schematic diagram ofFIG. 1 taken along section lines2-2.FIG. 2 illustrates a detail view of thesclera8 and surrounding tissue. As shown, theconjunctiva7 attaches to thesclera8 at thelimbus9.
• Deep to theconjunctiva7 is Tenon'scapsule10, sometimes referred to as Tenon's membrane or Tenon's tendon. Tenon'scapsule10 comprises two layers (i.e., superficial and deep layers) and anintra-Tenon's adhesion space10 that extends between the superficial and deep layers of Tenon'scapsule10. Theintra-Tenon's adhesion space11 surrounds the eye circumferentially. Theintra-Tenon's adhesion space11 can extend around the eye posterior to thelimbus9.
• In the view ofFIG. 2, deep to theintra-Tenon's adhesion space11 is arectus muscle20. The eye has four rectus muscles (superior, inferior, lateral, and medial) that attach to sclera via a rectus tendon.FIG. 2 illustrates that therectus muscle20 attaches to thesclera8 via arectus tendon22. For illustration purposes, therectus tendon22 is shown inserting onto thesclera8. In some cases, there may not be a clear insertion point of therectus tendon22 onto thesclera8, but there will be a gradual transition between therectus tendon22 and theintra-Tenon's adhesion space11.
• Additionally, as illustrated inFIG. 1, Tenon'scapsule10 and theintra-Tenon's adhesion space11 is illustrated extending anteriorly relative to and superficial to therectus muscle20. As also shown, posterior to the rectus tendon, Tenon'scapsule10 and theintra-Tenon's adhesion space11 also extend deep to and around therectus muscle20. In this region, there is a reflection of Tenon'scapsule10 and theintra-Tenon's adhesion space11 from therectus muscle20 onto the globe orsclera8. Thus, Tenon'scapsule10 and theintra-Tenon's adhesion space11 envelop or encapsulate therectus muscle20.
• FIG. 2 illustrates that in some locations, Tenon'scapsule10, and thus, theintra-Tenon's adhesion space11, surrounds arectus muscle20. According to some embodiments of the methods disclosed herein, theintra-Tenon's adhesion space11 can be accessed from theanterior chamber1. Tenon'scapsule10 and theintra-Tenon's adhesion space11 surround the eye circumferentially.
• FIG. 2 also illustrates the drainage channels of the eye, including Schlemm'scanal30 and thetrabecular meshwork32, which extend through thesclera8. Further, deep to thesclera8, theciliary body34 is also shown. Theciliary body34 transitions posteriorly to thechoroid40. Deep to thelimbus9 is ascleral spur36. Thescleral spur36 extends circumferentially within theanterior chamber1 of the eye. Further, thescleral spur36 is disposed anteriorly to theanterior chamber angle38. Furthermore, “anterior chamber angle tissue” can refer to the eye tissue in the region extending along and/or including one or more of thecornea2, thesclera8, Schlemm'scanal30, thetrabecular meshwork32, theciliary body34, theiris35, or thescleral spur36.
• Accordingly, for definitional purposes, the space between theconjunctiva7 and Tenon's capsule or theintra-Tenon's adhesion space11 is referred to herein as subconjunctival space332 (here shown as a potential space). Further, the space within adeep layer360 and asuperficial layer370 of Tenon'scapsule10 is referred to herein as theintra-Tenon's adhesion space11. Additionally, the space within the sclera8 (i.e., between the superficial and deep layers of the sclera8) is referred to herein as intrascleral space342 (here shown as a potential space). The space between thesclera8 and theciliary body34 is referred to herein as supraciliary space310 (here shown as a potential space). Finally, the space between thesclera8 and thechoroid40 is referred to as suprachoroidal space322 (here shown as a potential space). Thesupraciliary space310 can be continuous with thesuprachoroidal space322.
• Ab interno approaches for implanting an intraocular shunt in the subconjunctival space are shown for example in Yu et al. (U.S. Pat. No. 6,544,249 and U.S. Patent Publication No. 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511), the contents of each of which are incorporated by reference herein in its entirety. Briefly and with reference toFIG. 3, a surgical intervention to implant the shunt involves inserting into the eye adeployment device115 that holds an intraocular shunt, and deploying the shunt within theeye116. Adeployment device115 holding the shunt enters theeye116 through the cornea117 (ab interno approach). Thedeployment device115 is advanced across the anterior chamber120 (as depicted by the broken line) in what is referred to as a transpupil implant insertion. Thedeployment device115 is advanced through thesclera121 until a distal portion of the device is in proximity to thesubconjunctival space118 deep to theconjunctiva119. The shunt is then deployed from the deployment device, producing a conduit between the anterior chamber and the subconjunctival space to allow aqueous humor to drain through the conjunctival lymphatic system.
• While such ab interno subconjunctival filtration procedures have been successful in relieving intraocular pressure, there is a substantial risk that the intraocular shunt may be deployed too close to the conjunctiva, resulting in irritation and subsequent inflammation and/or scarring of the conjunctiva, which can cause the glaucoma filtration procedure to fail (See Yu et al., Progress in Retinal and Eye Research, 28:303-325 (2009)). Additionally, commercially available shunts that are currently utilized in such procedures are not ideal for ab interno subconjunctival placement due to the length of the shunt (i.e., too long) and/or the materials used to make the shunt (e.g., gold, polymer, titanium, or stainless steel), and can cause significant irritation to the tissue surrounding the shunt, as well as the conjunctiva, if deployed too close.
• The present disclosure provides methods for implanting intraocular shunts within the sclera (i.e., intrascleral implantation) and are thus suitable for use in an glaucoma filtration procedure (ab interno or ab externo). In some embodiments of the methods disclosed herein, the implanted shunt forms a passage from the anterior chamber of the eye into the sclera (i.e., intrascleral space). Design and/or deployment of an intraocular shunt such that the inlet terminates in the anterior chamber and the outlet terminates intrascleral safeguard the integrity of the conjunctiva to allow subconjunctival drainage pathways to successfully form. Additionally, drainage into the intrascleral space provides access to more lymphatic channels than just the conjunctival lymphatic system, such as the episcleral lymphatic network.
• Additionally, some embodiments of the methods disclosed herein recognize that while intrascleral shunt placement avoids contact with the conjunctiva, fluid outflow from the shunt into the intrascleral space may overwhelm the natural drainage structures (e.g., the episcleral vessel complex) proximate the intrascleral space. According to some embodiments, the present disclosure can combine intrascleral shunt placement with creation of a passageway through the sclera, thereby facilitating fluid drainage from the intrascleral space. Such a passageway facilitates diffusion of fluid into the subconjunctival and suprachoroidal spaces. Accordingly, the advantages of intrascleral shunt placement are recognized and the additional drainage passageway prevents the natural drainage structures proximate the intrascleral space from becoming overwhelmed with fluid output from the shunt.
Embodiments of Intraocular Shunts
• According to some embodiments, the present disclosure provides intraocular shunts that are configured to form a drainage pathway from the anterior chamber of the eye to the intrascleral space. In particular, according to some embodiments, the intraocular shunts have a length that is sufficient to form a drainage pathway from the anterior chamber of the eye to the intrascleral space. The length of the shunt is important for achieving placement specifically in the intrascleral space. A shunt that is too long will extend beyond the intrascleral space and irritate the conjunctiva which can cause the filtration procedure to fail, as previously described. A shunt that is too short will not provide sufficient access to drainage pathways such as the episcleral lymphatic system or the conjunctival lymphatic system.
• According to some embodiments, shunts used in methods disclosed herein may be any length that allows for drainage of aqueous humor from an anterior chamber of an eye to the intrascleral space. Exemplary shunts range in length from about 1 mm to about 10 mm or between about 2 mm to about 6 mm, or any specific value within said ranges. In certain embodiments, the length of the shunt is between about 2 mm to about 4 mm, or any specific value within said range. According to some embodiments, the intraocular shunts disclosed herein can be particularly suitable for use in an ab interno glaucoma filtration procedure. Commercially available shunts that are currently used in ab interno filtration procedures are typically made of a hard, inflexible material such as gold, polymer, titanium, or stainless steel, and cause substantial irritation of the eye tissue, resulting in ocular inflammation such as subconjunctival blebbing or endophthalmitis. Some embodiments of the methods disclosed herein may be conducted using any commercially available shunts, such as the Optonol Ex-PRESS™ mini Glaucoma shunt, and the Solx DeepLight Gold™ Micro-Shunt.
• In some embodiments, the intraocular shunts disclosed herein can be flexible, and have an elasticity modulus that is substantially identical to the elasticity modulus of the surrounding tissue in the implant site. As such, some embodiments of the intraocular shunts disclosed herein can be easily bendable, do not erode or cause a tissue reaction, and do not migrate once implanted. Thus, when implanted in the eye using an ab interno procedure, such as the methods described herein, some embodiments of the intraocular shunts disclosed herein do not induce substantial ocular inflammation such as subconjunctival blebbing or endophthalmitis. Additional exemplary features of some embodiments of intraocular shunts are discussed in further detail below.
Tissue Compatible Shunts
• In certain aspects, the present disclosure generally provides shunts composed of a material that has an elasticity modulus that is compatible with an elasticity modulus of tissue surrounding the shunt. In this manner, some embodiments of the shunts can be flexibility matched with the surrounding tissue, and thus will remain in place after implantation without the need for any type of anchor that interacts with the surrounding tissue. Consequently, some embodiments of the shunt will maintain fluid flow away for an anterior chamber of the eye after implantation without causing irritation or inflammation to the tissue surrounding the eye.
• Elastic modulus, or modulus of elasticity, is a mathematical description of an object or substance's tendency to be deformed elastically when a force is applied to it. The elastic modulus of an object is defined as the slope of its stress-strain curve in the elastic deformation region:
• $\lambda \stackrel{\mathrm{def}}{=}\frac{\mathrm{Stress}}{\mathrm{Strain}}$
• where lambda (λ) is the elastic modulus, stress is the force causing the deformation divided by the area to which the force is applied; and strain is the ratio of the change caused by the stress to the original state of the object. The elasticity modulus may also be known as Young's modulus (E), which describes tensile elasticity, or the tendency of an object to deform along an axis when opposing forces are applied along that axis. Young's modulus is defined as the ratio of tensile stress to tensile strain. For further description regarding elasticity modulus and Young's modulus, see for example Gere (Mechanics of Materials, 6th Edition, 2004, Thomson), the content of which is incorporated by reference herein in its entirety.
• The elasticity modulus of any tissue can be determined by one of skill in the art. See for example Samani et al. (Phys. Med. Biol. 48:2183, 2003); Erkamp et al. (Measuring The Elastic Modulus Of Small Tissue Samples, Biomedical Engineering Department and Electrical Engineering and Computer Science Department University of Michigan Ann Arbor, Mich. 48109-2125; and Institute of Mathematical Problems in Biology Russian Academy of Sciences, Pushchino, Moscow Region 142292 Russia); Chen et al. (IEEE Trans. Ultrason. Ferroelec. Freq. Control 43:191-194, 1996); Hall, (In 1996 Ultrasonics Symposium Proc., pp. 1193-1196, IEEE Cat. No. 96CH35993, IEEE, New York, 1996); and Parker (Ultrasound Med. Biol. 16:241-246, 1990), each of which provides methods of determining the elasticity modulus of body tissues. The content of each of these is incorporated by reference herein in its entirety.
• The elasticity modulus of tissues of different organs is known in the art. For example, Pierscionek et al. (Br J Ophthalmol, 91:801-803, 2007) and Friberg (Experimental Eye Research, 473:429-436, 1988) show the elasticity modulus of the cornea and the sclera of the eye. The content of each of these references is incorporated by reference herein in its entirety. Chen, Hall, and Parker show the elasticity modulus of different muscles and the liver. Erkamp shows the elasticity modulus of the kidney.
• Some embodiments of the shunts can be composed of a material that is compatible with an elasticity modulus of tissue surrounding the shunt. In certain embodiments, the material has an elasticity modulus that is substantially identical to the elasticity modulus of the tissue surrounding the shunt. In other embodiments, the material has an elasticity modulus that is greater than the elasticity modulus of the tissue surrounding the shunt. Exemplary materials includes biocompatible polymers, such as polycarbonate, polyethylene, polyethylene terephthalate, polyimide, polystyrene, polypropylene, poly(styrene-b-isobutylene-b-styrene), or silicone rubber.
• In some embodiments, the shunt can be composed of a material that has an elasticity modulus that is compatible with the elasticity modulus of tissue in the eye, particularly scleral tissue. In certain embodiments, compatible materials are those materials that are softer than scleral tissue or marginally harder than scleral tissue, yet soft enough to prohibit shunt migration. The elasticity modulus for anterior scleral tissue is about 2.9±1.4×106 N/m2, and 1.8±1.1×106 N/m2 for posterior scleral tissue. See Friberg (Experimental Eye Research, 473:429-436, 1988). An exemplary material is cross linked gelatin derived from Bovine or Porcine Collagen.
• The present disclosure encompasses shunts of different shapes and different dimensions, and some embodiments of the shunts disclosed herein may be any shape or any dimension that may be accommodated by the eye. In certain embodiments, the intraocular shunt is of a cylindrical shape and has an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter from about 10 μm to about 250 μm, an outside diameter from about 100 μm to about 450 μm, and a length from about 2 mm to about 10 mm.
Shunts Reactive to Pressure
• In other aspects, the present disclosure generally provides shunts in which a portion of the shunt is composed of a flexible material that is reactive to pressure, i.e., the diameter of the flexible portion of the shunt fluctuates depending upon the pressures exerted on that portion of the shunt.FIG. 5 provides a schematic of ashunt123 having aflexible portion151. In this figure, theflexible portion151 is shown in the middle of theshunt123. However, theflexible portion151 may be located in any portion of the shunt, such as the proximal or distal portion of the shunt. In certain embodiments, the entire shunt is composed of the flexible material, and thus the entire shunt is flexible and reactive to pressure.
• Theflexible portion151 of theshunt123 acts as a valve that regulates fluid flow through the shunt. The human eye produces aqueous humor at a rate of about 2 μl/min for about 3 ml/day. The entire aqueous volume is about 0.25 ml. When the pressure in the anterior chamber falls after surgery to about 7 mmHg to about 8 mmHg, it is assumed the majority of the aqueous humor is exiting the eye through the implant since venous backpressure prevents any significant outflow through normal drainage structures (e.g., the trabecular meshwork).
• After implantation, intraocular shunts have pressure exerted upon them by tissues surrounding the shunt (e.g., scleral tissue such as the sclera channel and the sclera exit) and pressure exerted upon them by aqueous humor flowing through the shunt. The flow through the shunt, and thus the pressure exerted by the fluid on the shunt, is calculated by the equation:
• $\Phi =\frac{\mathrm{dV}}{\mathrm{dT}}=v\pi {\mathrm{<figure-callout\; label="R"\; filenames="US20220304856A1-20220929-D00001.png,US20220304856A1-20220929-D00002.png"\; state="\{\{state\}\}">R</figure-callout>}}^2=\frac{\pi {\mathrm{<figure-callout\; label="R"\; filenames="US20220304856A1-20220929-D00001.png"\; state="\{\{state\}\}">R</figure-callout>}}^4}{8\eta }\left(\frac{-\Delta P}{\Delta x}\right)=\frac{\pi {\mathrm{<figure-callout\; label="R"\; filenames="US20220304856A1-20220929-D00001.png"\; state="\{\{state\}\}">R</figure-callout>}}^4}{8\eta }\frac{❘\Delta P❘}{L}$
• where Φ is the volumetric flow rate; V is a volume of the liquid poured (cubic meters); t is the time (seconds); v is mean fluid velocity along the length of the tube (meters/second); x is a distance in direction of flow (meters); R is the internal radius of the tube (meters); ΔP is the pressure difference between the two ends (pascals); η is the dynamic fluid viscosity (pascal-second (Pa·s)); and L is the total length of the tube in the x direction (meters).
• FIG. 6A provides a schematic of ashunt126 implanted into an eye for regulation of fluid flow from the anterior chamber of the eye to an area of lower pressure (e.g., the intrascleral space). The shunt is implanted such that aproximal end127 of theshunt126 resides in theanterior chamber128 of the eye, and adistal end129 of theshunt126 resides outside of the anterior chamber to conduct aqueous humor from the anterior chamber to an area of lower pressure. Aflexible portion130 of theshunt126 spans at least a portion of the sclera of the eye. As shown inFIG. 6A, the flexible portion spans an entire length of thesclera131.
• When the pressure exerted on theflexible portion130 of theshunt126 by sclera131 (vertical arrows) is greater than the pressure exerted on theflexible portion130 of theshunt126 by the fluid flowing through the shunt (horizontal arrow), theflexible portion130 decreases in diameter, restricting flow through the shunt126 (FIG. 6B). The restricted flow results in aqueous humor leaving theanterior chamber128 at a reduced rate.
• When the pressure exerted on theflexible portion130 of theshunt126 by the fluid flowing through the shunt (horizontal arrow) is greater than the pressure exerted on theflexible portion130 of theshunt126 by the sclera131 (vertical arrows), theflexible portion130 increases in diameter, increasing flow through the shunt126 (FIG. 6C). The increased flow results in aqueous humor leaving theanterior chamber128 at an increased rate.
• The present disclosure encompasses shunts of different shapes and different dimensions, and some embodiments of the shunts disclosed herein may be any shape or any dimension that may be accommodated by the eye. In certain embodiments, the intraocular shunt is of a cylindrical shape and has an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter from about 10 μm to about 250 μm, an outside diameter from about 100 μm to about 450 μm, and a length from about 2 mm to about 10 mm.
• In some embodiments, the shunt has a length of about 6 mm and an inner diameter of about 64 μm. With these dimensions, the pressure difference between the proximal end of the shunt that resides in the anterior chamber and the distal end of the shunt that resides outside the anterior chamber is about 4.3 mmHg. Such dimensions thus allow the implant to act as a controlled valve and protect the integrity of the anterior chamber.
• It will be appreciated that different dimensioned implants may be used. For example, shunts that range in length from about 2 mm to about 10 mm and have a range in inner diameter from about 10 μm to about 100 μm allow for pressure control from about 0.5 mmHg to about 20 mmHg.
• The material of the flexible portion and the thickness of the wall of the flexible portion will determine how reactive the flexible portion is to the pressures exerted upon it by the surrounding tissue and the fluid flowing through the shunt. Generally, with a certain material, the thicker the flexible portion, the less responsive the portion will be to pressure. In certain embodiments, the flexible portion is a gelatin or other similar material, and the thickness of the gelatin material forming the wall of the flexible portion ranges from about 10 μm thick to about 100 μm thick.
• In a certain embodiment, the gelatin used for making the flexible portion is known as gelatin Type B from bovine skin. An exemplary gelatin is PB Leiner gelatin from bovine skin, Type B, 225 Bloom, USP. Another material that may be used in the making of the flexible is available from Sigma Chemical Company of St. Louis, Mo. under Code G-9382. Still other suitable gelatins include bovine bone gelatin, porcine bone gelatin and human-derived gelatins. In addition to gelatins, the flexible portion may be made of hydroxypropyl methylcellulose (HPMC), collagen, polylactic acid, polylglycolic acid, hyaluronic acid and glycosaminoglycans.
• In certain embodiments, the gelatin is cross-linked. Cross-linking increases the inter- and intramolecular binding of the gelatin substrate. Any method for cross-linking the gelatin may be used. In some embodiments, the formed gelatin is treated with a solution of a cross-linking agent such as, but not limited to, glutaraldehyde. Other suitable compounds for cross-linking include 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). Cross-linking by radiation, such as gamma or electron beam (e-beam) may be alternatively employed.
• In one embodiment, the gelatin is contacted with a solution of about 25% glutaraldehyde for a selected period of time. One suitable form of glutaraldehyde is a grade 1G5882 glutaraldehyde available from Sigma Aldridge Company of Germany, although other glutaraldehyde solutions may also be used. The pH of the glutaraldehyde solution should be in the range of about 7 to about 7.8 and, more particularly, about 7.35 to about 7.44 and typically about 7.4+/−0.01. If necessary, the pH may be adjusted by adding a suitable amount of a base such as sodium hydroxide as needed.
• Methods for forming the flexible portion of the shunt are shown for example in Yu et al. (U.S. patent application number 2008/0108933), the content of which is incorporated by reference herein in its entirety. In an exemplary protocol, the flexible portion may be made by dipping a core or substrate such as a wire of a suitable diameter in a solution of gelatin. The gelatin solution is typically prepared by dissolving a gelatin powder in de-ionized water or sterile water for injection and placing the dissolved gelatin in a water bath at a temperature of about 55° C. with thorough mixing to ensure complete dissolution of the gelatin. In one embodiment, the ratio of solid gelatin to water is about 10% to about 50% gelatin by weight to about 50% to about 90% by weight of water. In an embodiment, the gelatin solution includes about 40% by weight, gelatin dissolved in water. The resulting gelatin solution should be devoid of air bubbles and has a viscosity that is between about 200 centipoise (“cp”) to about 500 cp and more particularly between about 260 cp and about 410 cp.
• Once the gelatin solution has been prepared, in accordance with the method described above, supporting structures such as wires having a selected diameter are dipped into the solution to form the flexible portion. Stainless steel wires coated with a biocompatible, lubricious material such as polytetrafluoroethylene (Teflon) are preferred.
• Typically, the wires are gently lowered into a container of the gelatin solution and then slowly withdrawn. The rate of movement is selected to control the thickness of the coat. In addition, it is preferred that the tube be removed at a constant rate in order to provide the desired coating. To ensure that the gelatin is spread evenly over the surface of the wire, in one embodiment, the wires may be rotated in a stream of cool air which helps to set the gelatin solution and affix film onto the wire. Dipping and withdrawing the wire supports may be repeated several times to further ensure even coating of the gelatin. Once the wires have been sufficiently coated with gelatin, the resulting gelatin films on the wire may be dried at room temperature for at least 1 hour, and more preferably, about 10 hours to about 24 hours. Apparatus for forming gelatin tubes are described in Yu et al. (U.S. patent application number 2008/0108933).
• Once dried, the formed flexible portions may be treated with a cross-linking agent. In one embodiment, the formed flexible portion may be cross-linked by dipping the wire (with film thereon) into the 25% glutaraldehyde solution, at pH of from about 7.0 to about 7.8 and more preferably from about 7.35 to about 7.44 at room temperature for at least about 4 hours and preferably from about 10 to about 36 hours, depending on the degree of cross-linking desired. In one embodiment, the formed flexible portion is contacted with a cross-linking agent such as glutaraldehyde for at least about 16 hours. Cross-linking can also be accelerated when it is performed a high temperatures. It is believed that the degree of cross-linking is proportional to the bioabsorption time of the shunt once implanted. In general, the more cross-linking, the longer the survival of the shunt in the body.
• The residual glutaraldehyde or other cross-linking agent is removed from the formed flexible portion by soaking the tubes in a volume of sterile water for injection. The water may optionally be replaced at regular intervals, circulated or re-circulated to accelerate diffusion of the unbound glutaraldehyde from the tube. The tubes are washed for a period of a few hours to a period of a few months with the ideal time being from about 3 days to about 14 days. The now cross-linked gelatin tubes may then be dried (cured) at ambient temperature for a selected period of time. It has been observed that a drying period of from about 48 to about 96 hours and more typically 3 days (i.e., 72 hours) may be preferred for the formation of the cross-linked gelatin tubes.
• Where a cross-linking agent is used, it may be desirable to include a quenching agent in the method of making the flexible portion. Quenching agents remove unbound molecules of the cross-linking agent from the formed flexible portion. In certain cases, removing the cross-linking agent may reduce the potential toxicity to a patient if too much of the cross-linking agent is released from the flexible portion. In certain embodiments, the formed flexible portion is contacted with the quenching agent after the cross-linking treatment and, may be included with the washing/rinsing solution. Examples of quenching agents include glycine or sodium borohydride.
• After the requisite drying period, the formed and cross-linked flexible portion is removed from the underlying supports or wires. In one embodiment, wire tubes may be cut at two ends and the formed gelatin flexible portion slowly removed from the wire support. In another embodiment, wires with gelatin film thereon may be pushed off using a plunger or tube to remove the formed gelatin flexible portion.
Multi-Port Shunts
• Other aspects of the present disclosure generally provide multi-port shunts. Such shunts reduce probability of the shunt clogging after implantation because fluid can enter or exit the shunt even if one or more ports of the shunt become clogged with particulate. In certain embodiments, the shunt includes a hollow body defining a flow path and more than two ports, in which the body is configured such that a proximal portion receives fluid from the anterior chamber of an eye and a distal portion directs the fluid to drainage structures associated with the intrascleral space.
• The shunt may have many different configurations.FIG. 7A shows an embodiment of ashunt132 in which the proximal portion of the shunt (i.e., the portion disposed within the anterior chamber of the eye) includes more than one port (designated asnumbers133ato133e) and the distal portion of the shunt (i.e., the portion that is located in the intrascleral space) includes asingle port134.FIG. 7B shows another embodiment of ashunt132 in which the proximal portion includes asingle port133 and the distal portion includes more than one port (designated asnumbers134ato134e).FIG. 7C shows another embodiment of ashunt132 in which the proximal portions include more than one port (designated asnumbers133ato133e) and the distal portions include more than one port (designated asnumbers134ato134e). WhileFIGS. 7A-7C show shunts having ports at the proximal portion, distal portion, or both, those shunts are only exemplary embodiments. The ports may be located along any portion of the shunt, and some embodiments of the shunts disclosed herein include all shunts having more than two ports. For example, some embodiments of the shunts disclosed herein may include at least three ports, at least four ports, at least five ports, at least 10 ports, at least 15 ports, or at least 20 ports.
• The ports may be positioned in various different orientations and along various different portions of the shunt. In certain embodiments, at least one of the ports is oriented at an angle to the length of the body. In certain embodiments, at least one of the ports is oriented 90° to the length of the body. See for exampleFIG. 7A, which depictsports133a,133b,133d, and133eas being oriented at a 90° angle to port133c.
• The ports may have the same or different inner diameters. In certain embodiments, at least one of the ports has an inner diameter that is different from the inner diameters of the other ports.FIGS. 8A and 8B show an embodiment of ashunt132 having multiple ports (133aand133b) at a proximal end and asingle port134 at a distal end.FIG. 8A shows thatport133bhas an inner diameter that is different from the inner diameters ofports133aand134. In this figure, the inner diameter ofport133bis less than the inner diameter ofports133aand134. An exemplary inner diameter ofport133bis from about 20 μm to about 40 μm, particularly about 30 μm. In other embodiments, the inner diameter ofport133bis greater than the inner diameter ofports133aand134. See, for example,FIG. 8B.
• The present disclosure encompasses shunts of different shapes and different dimensions, and the some embodiments of the shunts disclosed herein may be any shape or any dimension that may be accommodated by the eye. In certain embodiments, the intraocular shunt is of a cylindrical shape and has an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter from about 10 μm to about 250 μm, an outside diameter from about 100 μm to about 450 μm, and a length from about 0.5 mm to about 20 mm. Some embodiments of the shunts disclosed herein may be made from any biocompatible material. An exemplary material is gelatin. Methods of making shunts composed of gelatin are described above.
• Shunts with Overflow Ports
• Other aspects of the present disclosure generally provide shunts with overflow ports. Those shunts are configured such that the overflow port remains partially or completely closed until there is a pressure build-up within the shunt sufficient to force open the overflow port. Such pressure build-up typically results from particulate partially or fully clogging an entry or an exit port of the shunt. Such shunts reduce probability of the shunt clogging after implantation because fluid can enter or exit the shunt by the overflow port even if one port of the shunt becomes clogged with particulate.
• In certain embodiments, the shunt includes a hollow body defining an inlet configured to receive fluid from an anterior chamber of an eye and an outlet configured to direct the fluid to the intrascleral space, the body further including at least one slit. The slit may be located at any place along the body of the shunt.FIG. 9A shows ashunt135 having aninlet136, anoutlet137, and aslit138 located in proximity to theinlet136.FIG. 9B shows ashunt135 having aninlet136, anoutlet137, and aslit139 located in proximity to theoutlet137.FIG. 9C shows ashunt135 having aninlet136, anoutlet137, aslit138 located in proximity to theinlet136, and aslit139 located in proximity to theoutlet137.
• WhileFIGS. 9A-9C show shunts have only a single overflow port at the proximal portion, the distal portion, or both the proximal and distal portions, those shunts are only exemplary embodiments. The overflow port(s) may be located along any portion of the shunt, and some embodiments of the shunts disclosed herein include shunts having more than one overflow port. In certain embodiments, some embodiments of the shunts disclosed herein include more than one overflow port at the proximal portion, the distal portion, or both. For example,FIG. 10 shows ashunt140 having aninlet141, anoutlet142, and slits143aand143blocated in proximity to theinlet141. Some embodiments of the shunts disclosed herein may include at least two overflow ports, at least three overflow ports, at least four overflow ports, at least five overflow ports, at least 10 overflow ports, at least 15 overflow ports, or at least 20 overflow ports. In certain embodiments, some embodiments of the shunts disclosed herein include two slits that overlap and are oriented at 90° to each other, thereby forming a cross.
• In certain embodiments, the slit may be at the proximal or the distal end of the shunt, producing a split in the proximal or the distal end of the implant.FIG. 11 shows an embodiment of ashunt144 having aninlet145,outlet146, and aslit147 that is located at the proximal end of the shunt, producing a split in theinlet145 of the shunt.
• In certain embodiments, the slit has a width that is substantially the same or less than an inner diameter of the inlet. In other embodiments, the slit has a width that is substantially the same or less than an inner diameter of the outlet. In certain embodiments, the slit has a length that ranges from about 0.05 mm to about 2 mm, and a width that ranges from about 10 μm to about 200 μm. Generally, the slit does not direct the fluid unless the outlet is obstructed. However, the shunt may be configured such that the slit does direct at least some of the fluid even if the inlet or outlet is not obstructed.
• The present disclosure encompasses shunts of different shapes and different dimensions, and some embodiments of the shunts disclosed herein may be any shape or any dimension that may be accommodated by the eye. In certain embodiments, the intraocular shunt is of a cylindrical shape and has an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter from about 10 μm to about 250 μm, an outside diameter from about 100 μm to about 450 μm, and a length from about 2 mm to about 10 mm. Some embodiments of the shunts disclosed herein may be made from any biocompatible material. An exemplary material is gelatin. Methods of making shunts composed of gelatin are described above.
Shunts Having a Variable Inner Diameter
• In other aspects, the present disclosure generally provides a shunt having a variable inner diameter. In some embodiments, the diameter increases from inlet to outlet of the shunt. By having a variable inner diameter that increases from inlet to outlet, a pressure gradient is produced and particulate that may otherwise clog the inlet of the shunt is forced through the inlet due to the pressure gradient. Further, the particulate will flow out of the shunt because the diameter only increases after the inlet.
• FIG. 12 shows an embodiment of ashunt148 having aninlet149 configured to receive fluid from an anterior chamber of an eye and anoutlet150 configured to direct the fluid to a location of lower pressure with respect to the anterior chamber, in which the body further includes a variable inner diameter that increases along the length of the body from theinlet149 to theoutlet150. In certain embodiments, the inner diameter continuously increases along the length of the body, for example as shown inFIG. 12. In other embodiments, the inner diameter remains constant along portions of the length of the body.
• In exemplary embodiments, the inner diameter may range in size from about 10 μm to about 200 μm, and the inner diameter at the outlet may range in size from about 15 μm to about 300 μm. The present disclosure encompasses shunts of different shapes and different dimensions, and some embodiments of the shunts disclosed herein may be any shape or any dimension that may be accommodated by the eye. In certain embodiments, the intraocular shunt is of a cylindrical shape and has an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter from about 10 μm to about 250 μm, an outside diameter from about 100 μm to about 450 μm, and a length from about 2 mm to about 10 mm. Shunts of the invention may be made from any biocompatible material. An exemplary material is gelatin. Methods of making shunts composed of gelatin are described above.
Shunts Having Pronged Ends
• In other aspects, the present disclosure generally provides shunts for facilitating conduction of fluid flow away from an organ, the shunt including a body, in which at least one end of the shunt is shaped to have a plurality of prongs. Such shunts reduce probability of the shunt clogging after implantation because fluid can enter or exit the shunt by any space between the prongs even if one portion of the shunt becomes clogged with particulate.
• FIGS. 13A-13D show embodiments of ashunt152 in which at least one end of theshunt152 includes a plurality of prongs153a-153d.FIGS. 13A-13D show embodiments in which both a proximal end and a distal end of the shunt are shaped to have the plurality of prongs. However, numerous different configurations are envisioned. For example, in certain embodiments, only the proximal end of the shunt is shaped to have the plurality of prongs. In other embodiments, only the distal end of the shunt is shaped to have the plurality of prongs.
• Prongs153a-153dcan have any shape (i.e., width, length, height).FIGS. 13A-13B show prongs153a-153das straight prongs. In this embodiment, the spacing between the prongs153a-153dis the same. In another embodiment shown inFIGS. 13C-13D, prongs153a-153dare tapered. In this embodiment, the spacing between the prongs increases toward a proximal and/or distal end of theshunt152.
• FIGS. 13A-13D show embodiments that include four prongs. However, some embodiments of the shunts disclosed herein may accommodate any number of prongs, such as two prongs, three prongs, four prongs, five prongs, six prongs, seven prongs, eight prongs, nine prongs, ten prongs, etc. The number of prongs chosen will depend on the desired flow characteristics of the shunt.
• The present disclosure encompasses shunts of different shapes and different dimensions, and some embodiments of the shunts disclosed herein may be any shape or any dimension that may be accommodated by the eye. In certain embodiments, the intraocular shunt is of a cylindrical shape and has an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter from about 10 μm to about 250 μm, an outside diameter from about 100 μm to about 450 μm, and a length from about 2 mm to about 10 mm. Some embodiments of the shunts disclosed herein may be made from any biocompatible material. An exemplary material is gelatin. Methods of making shunts composed of gelatin are described above.
Shunts Having a Longitudinal Slit
• In other aspects, the present disclosure generally provides a shunt for draining fluid from an anterior chamber of an eye that includes a hollow body defining an inlet configured to receive fluid from an anterior chamber of the eye and an outlet configured to direct the fluid to a location of lower pressure with respect to the anterior chamber; the shunt being configured such that at least one end of the shunt includes a longitudinal slit. Such shunts reduce probability of the shunt clogging after implantation because the end(s) of the shunt can more easily pass particulate which would generally clog a shunt lacking the slits.
• FIGS. 14A-14D show embodiments of ashunt154 in which at least one end of theshunt154 includes alongitudinal slit155 that produces atop portion156aand abottom portion156bin a proximal and/or distal end of theshunt154.FIGS. 14A-14D show an embodiment in which both a proximal end and a distal end include alongitudinal slit155 that produces atop portion156aand abottom portion156bin both ends of theshunt154. However, numerous different configurations are envisioned. For example, in certain embodiments, only the proximal end of the shunt includeslongitudinal slit155. In other embodiments, only the distal end of the shunt includeslongitudinal slit155.
• Longitudinal slit155 can have any shape (i.e., width, length, height).FIGS. 14A-14B show alongitudinal slit155 that is straight such that the space between thetop portion156aand thebottom portion156bremains the same along the length of theslit155. In another embodiment shown inFIGS. 14C-14D,longitudinal slit155 is tapered. In this embodiment, the space between the top portion145aand thebottom portion156bincreases toward a proximal and/or distal end of theshunt154.
• The present disclosure encompasses shunts of different shapes and different dimensions, and the some embodiments of the shunts disclosed herein may be any shape or any dimension that may be accommodated by the eye. In certain embodiments, the intraocular shunt is of a cylindrical shape and has an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter from about 10 μm to about 250 μm, an outside diameter from about 100 μm to about 450 μm, and a length from about 2 mm to about 10 mm. Some embodiments of the shunts disclosed herein may be made from any biocompatible material. An exemplary material is gelatin. Methods of making shunts composed of gelatin are described above.
Pharmaceutical Agents
• In certain embodiments, some embodiments of the shunts disclosed herein may be coated or impregnated with at least one pharmaceutical and/or biological agent or a combination thereof. The pharmaceutical and/or biological agent may coat or impregnate an entire exterior of the shunt, an entire interior of the shunt, or both. Alternatively, the pharmaceutical or biological agent may coat and/or impregnate a portion of an exterior of the shunt, a portion of an interior of the shunt, or both. Methods of coating and/or impregnating an intraocular shunt with a pharmaceutical and/or biological agent are known in the art. See for example, Darouiche (U.S. Pat. Nos. 7,790,183; 6,719,991; 6,558,686; 6,162,487; 5,902,283; 5,853,745; and 5,624,704) and Yu et al. (U.S. Patent App. No. 2008/0108933). The content of each of these references is incorporated by reference herein its entirety.
• In certain embodiments, the exterior portion of the shunt that resides in the anterior chamber after implantation (e.g., about 1 mm of the proximal end of the shunt) is coated and/or impregnated with the pharmaceutical or biological agent. In other embodiments, the exterior of the shunt that resides in the scleral tissue after implantation of the shunt is coated and/or impregnated with the pharmaceutical or biological agent. In other embodiments, the exterior portion of the shunt that resides in the intrascleral space after implantation is coated and/or impregnated with the pharmaceutical or biological agent. In embodiments in which the pharmaceutical or biological agent coats and/or impregnates the interior of the shunt, the agent may be flushed through the shunt and into the area of lower pressure (e.g., the intrascleral space).
• Any pharmaceutical and/or biological agent or combination thereof may be used with some embodiments of the shunts disclosed herein. The pharmaceutical and/or biological agent may be released over a short period of time (e.g., seconds) or may be released over longer periods of time (e.g., days, weeks, months, or even years). Exemplary agents include anti-mitotic pharmaceuticals such as Mitomycin-C or 5-Fluorouracil, anti-VEGF (such as Lucentis, Macugen, Avastin, VEGF or steroids).
Deployment Devices
• Any deployment device or system known in the art may be used with some embodiments of the methods disclosed herein. In certain embodiments, deployment into the eye of an intraocular shunt according to some embodiments can be achieved using a hollow shaft configured to hold the shunt, as described herein. The hollow shaft can be coupled to a deployment device or part of the deployment device itself. Deployment devices that are suitable for deploying shunts according to some embodiments include, but are not limited to the deployment devices described in U.S. Pat. Nos. 6,007,511, 6,544,249, U.S. Publication No. 2008/0108933, U.S. Patent App. No. 61/904,429, filed on Nov. 14, 2013, and U.S. patent application Ser. No. 14/313,970, filed on Jun. 24, 2013, the contents of which are each incorporated herein by reference in their entireties. In other embodiments, the deployment devices are devices as described in co-pending and co-owned U.S. patent application Ser. No. 12/946,222 filed on Nov. 15, 2010, or deployment devices described in co-pending and co-owned U.S. patent application Ser. No. 12/946,645 filed on Nov. 15, 2010, the entire content of each of which is incorporated by reference herein.
• A shunt deployment device, such as those disclosed herein, can be used to implant the shunt in accordance with a variety of potential procedures, which can be modified or updated, according to aspects of the disclosure herein, as well as future methodologies and device features. For example, as discussed and shown below with regard toFIGS. 52A-54E, a shunt deployment device can be used to implant a shunt using a variety of different procedures. The deployment device can be manual or automatic and can include features of one or more of the devices discussed or mentioned herein.
• For example, in some embodiments, the shunts can be deployed into the eye using thedeployment device200 depicted inFIG. 15. WhileFIG. 15 shows a handheld, manually operated shunt deployment device, it will be appreciated that devices according to some embodiments may be coupled with robotic systems and may be completely or partially automated. As shown inFIG. 15,deployment device200 includes a generally cylindrical body orhousing201; however, the body shape ofhousing201 could be other than cylindrical.Housing201 may have an ergonomical shape, allowing for comfortable grasping by an operator.Housing201 is shown withoptional grooves202 to allow for easier gripping by a surgeon.
• According to some embodiments, the shunt can be advanced into the eye tissue at a rate of between about 0.15 mm/sec to about 0.85 mm/sec. Further, in some embodiments, the shunt can be advanced into the eye tissue at a rate of between about 0.25 mm/sec to about 0.65 mm/sec.
• Housing201 is shown having a larger proximal portion that tapers to a distal portion. The distal portion includes ahollow sleeve205. Thehollow sleeve205 is configured for insertion into an eye and to extend into an anterior chamber of an eye. Thehollow sleeve205 is visible within an anterior chamber of an eye. According to some embodiment, thesleeve205 can provide a visual preview or guide for an operator as to placement of the proximal portion of the shunt within the anterior chamber of an eye, as discussed below with regard toFIGS. 52A-52E. Thesleeve205 can provide a visual reference point that may be used by an operator to hold device100 steady during the shunt deployment process, thereby assuring optimal longitudinal placement of the shunt within the eye.
• According to some embodiments, thesleeve205 may also include an edge231 at a distal end that provides resistance feedback to an operator upon insertion of thedeployment device200 within an eye232 of a person during delivery of theshunt215, as discussed below with regard toFIGS. 53A-54E. Upon advancement of thedevice200 across an anterior chamber233 of the eye232, thehollow sleeve205 will eventually contact the anterior chamber angle tissue, and may abut sclera234, providing resistance feedback to an operator that no further advancement of thedevice200 is necessary. Atemporary guard208 is configured to fit aroundsleeve205 and extend beyond an end ofsleeve205. The edge231 of thesleeve205 prevents theshaft204 from accidentally being pushed too far through the sclera234. The guard is used during shipping of the device and protects an operator from a distal end of ahollow shaft204 that extends beyond the end of thesleeve205. The guard is removed prior to use of the device.
• Housing201 is open at its proximal end, such that a portion of adeployment mechanism203 may extend from the proximal end of thehousing201. A distal end ofhousing201 is also open such that at least a portion of ahollow shaft204 may extend through and beyond the distal end of thehousing201.Housing201 further includes aslot206 through which an operator, such as a surgeon, using thedevice200 may view anindicator207 on thedeployment mechanism203.
• Housing201 may be made of any material that is suitable for use in medical devices. For example,housing201 may be made of a lightweight aluminum or a biocompatible plastic material. Examples of such suitable plastic materials include polycarbonate and other polymeric resins such as DELRIN and ULTEM. In certain embodiments,housing201 is made of a material that may be autoclaved, and thus allow forhousing201 to be re-usable. Alternatively,device200 may be sold as a one-time-use device, and thus the material of the housing does not need to be a material that is autoclavable.
• Housing201 may be made of multiple components that connect together to form the housing.FIG. 16 shows an exploded view ofdeployment device200. In this figure,housing201 is shown having threecomponents201a,201b, and201c. The components are designed to screw together to formhousing201.FIGS. 17A-17D also showdeployment mechanism203. Thehousing201 is designed such thatdeployment mechanism203 fits within assembledhousing201.Housing201 is designed such that components ofdeployment mechanism203 are movable withinhousing201.
• FIGS. 17A-17D show different enlarged views of thedeployment mechanism203.Deployment mechanism203 may be made of any material that is suitable for use in medical devices. For example,deployment mechanism203 may be made of a lightweight aluminum or a biocompatible plastic material. Examples of such suitable plastic materials include polycarbonate and other polymeric resins such as DELRIN and ULTEM. In certain embodiments,deployment mechanism203 is made of a material that may be autoclaved, and thus allow fordeployment mechanism203 to be re-usable. Alternatively,device200 may be sold as a one-time-use device, and thus the material of the deployment mechanism does not need to be a material that is autoclavable.
• Deployment mechanism203 includes adistal portion209 and adistal portion210. Thedeployment mechanism203 is configured such thatdistal portion209 is movable withindistal portion210. More particularly,distal portion209 is capable of partially retracting to withinproximal portion210.
• In this embodiment, thedistal portion209 is shown to taper to a connection with ahollow shaft204. This embodiment is illustrated such that the connection between thehollow shaft204 and thedistal portion209 of thedeployment mechanism203 occurs inside thehousing201. In other embodiments, the connection betweenhollow shaft204 and thedistal portion209 of thedeployment mechanism203 may occur outside of thehousing201.Hollow shaft204 may be removable from thedistal portion209 of thedeployment mechanism203. Alternatively, thehollow shaft204 may be permanently coupled to thedistal portion209 of thedeployment mechanism203.
• Generally,hollow shaft204 is configured to hold an intraocular shunt, such as the intraocular shunts according to some embodiments. Theshaft204 may be any length. A usable length of the shaft may be anywhere from about 5 mm to about 40 mm, and is about 15 mm in certain embodiments. In certain embodiments, the shaft is straight. In other embodiments, shaft is of a shape other than straight, for example a shaft having a bend along its length.
• A proximal portion of the deployment mechanism includesoptional grooves216 to allow for easier gripping by an operator for easier rotation of the deployment mechanism, which will be discussed in more detail below. Theproximal portion210 of the deployment mechanism also includes at least one indicator that provides feedback to an operator as to the state of the deployment mechanism. The indicator may be any type of indicator known in the art, for example a visual indicator, an audio indicator, or a tactile indicator.FIGS. 17A and 17C show a deployment mechanism having two indicators, aready indicator211 and a deployedindicator219.Ready indicator211 provides feedback to an operator that the deployment mechanism is in a configuration for deployment of an intraocular shunt from thedeployment device200. Theready indicator211 is shown in this embodiment as a green oval having a triangle within the oval. Deployedindicator219 provides feedback to the operator that the deployment mechanism has been fully engaged and has deployed the shunt from thedeployment device200. The deployedindicator219 is shown in this embodiment as a yellow oval having a black square within the oval. The indicators are located on the deployment mechanism such that when assembled, theindicators211 and219 may be seen throughslot206 inhousing201.
• Theproximal portion210 includes astationary portion210band arotating portion210a. Theproximal portion210 includes achannel212 that runs part of the length ofstationary portion210band the entire length of rotatingportion210a. Thechannel212 is configured to interact with aprotrusion217 on an interior portion ofhousing component201a(FIGS. 18A and 18B). During assembly, theprotrusion217 onhousing component201ais aligned withchannel212 on thestationary portion210bandrotating portion210aof thedeployment mechanism203. Theproximal portion210 ofdeployment mechanism203 is slid withinhousing component201 a until theprotrusion217 sits withinstationary portion210b(FIG. 18C). Assembled, theprotrusion217 interacts with thestationary portion210bof thedeployment mechanism203 and prevents rotation ofstationary portion210b. In this configuration, rotatingportion210ais free to rotate withinhousing component201a.
• Referring back toFIGS. 17A-17D, the rotatingportion210aofproximal portion210 ofdeployment mechanism203 also includeschannels213a,213b, and213c.Channel213aincludes afirst portion213a1 that is straight and runs perpendicular to the length of therotating portion210a, and asecond portion213a2 that runs diagonally along the length of rotatingportion210a, downwardly toward a proximal end of thedeployment mechanism203.Channel213bincludes afirst portion213b1 that runs diagonally along the length of therotating portion210a, downwardly toward a distal end of thedeployment mechanism203, and a second portion that is straight and runs perpendicular to the length of therotating portion210a. The point at whichfirst portion213a1 transitions tosecond portion213a2 alongchannel213a, is the same as the point at whichfirst portion213b1 transitions tosecond portion213b2 alongchannel213b.Channel213cis straight and runs perpendicular to the length of therotating portion210a. Within each ofchannels213a,213b, and213c, sitmembers214a,214b, and214crespectively.Members214a,214b, and214care movable withinchannels213a,213b, and213c.Members214a,214b, and214calso act as stoppers that limit movement of rotatingportion210a, which thereby limits axial movement of theshaft204.
• FIG. 19 shows a cross-sectional view ofdeployment mechanism203.Member214ais connected to thedistal portion209 of thedeployment mechanism203. Movement ofmember214aresults in retraction of thedistal portion209 of thedeployment mechanism203 to within theproximal portion210 of thedeployment mechanism203.Member214bis connected to apusher component218. Thepusher component218 extends through thedistal portion209 of thedeployment mechanism203 and extends into a portion ofhollow shaft204. The pusher component is involved in deployment of a shunt from thehollow shaft204. An exemplary pusher component is a plunger. Movement ofmember214bengagespusher218 and results inpusher218 advancing withinhollow shaft204.
• Reference is now made toFIGS. 20A-22D, which accompany the following discussion regarding deployment of ashunt215 fromdeployment device200.FIG. 20A showsdeployment device200 in a pre-deployment configuration. In this configuration,shunt215 is loaded within hollow shaft204 (FIG. 20C). As shown inFIG. 20C,shunt215 is only partially withinshaft204, such that a portion of the shunt is exposed. However, theshunt215 does not extend beyond the end of theshaft204. In other embodiments, theshunt215 is completely disposed withinhollow shaft204. Theshunt215 is loaded intohollow shaft204 such that the shunt abutspusher component218 withinhollow shaft204. A distal end ofshaft204 is beveled to assist in piercing tissue of the eye.
• Additionally, in the pre-deployment configuration, a portion of theshaft204 extends beyond the sleeve205 (FIG. 20C). The deployment mechanism is configured such thatmember214aabuts a distal end of thefirst portion213a1 ofchannel213a, andmember214babuts a proximal end of thefirst portion213b1 ofchannel213b(FIG. 20B). In this configuration, theready indicator211 is visible throughslot206 of thehousing201, providing feedback to an operator that the deployment mechanism is in a configuration for deployment of an intraocular shunt from the deployment device200 (FIG. 20A). In this configuration, thedevice200 is ready for insertion into an eye (insertion configuration or pre-deployment configuration). Methods for inserting and implanting shunts are discussed in further detail below.
• Once the device has been inserted into the eye and advanced to a location to where the shunt will be deployed, theshunt215 may be deployed from thedevice200. Thedeployment mechanism203 is a two-stage system. The first stage is engagement of thepusher component218 and the second stage is retraction of thedistal portion209 to within theproximal portion210 of thedeployment mechanism203. Rotation of therotating portion210aof theproximal portion210 of thedeployment mechanism203 sequentially engages the pusher component and then the retraction component.
• In the first stage of shunt deployment, the pusher component is engaged and the pusher partially deploys the shunt from the deployment device. During the first stage, rotatingportion210aof theproximal portion210 of thedeployment mechanism203 is rotated, resulting in movement ofmembers214aand214balongfirst portions213a1 and213b1 inchannels213aand213b. Since thefirst portion213a1 ofchannel213ais straight and runs perpendicular to the length of therotating portion210a, rotation of rotatingportion210adoes not cause axial movement ofmember214a. Without axial movement ofmember214a, there is no retraction of thedistal portion209 to within theproximal portion210 of thedeployment mechanism203. Since thefirst portion213b1 ofchannel213bruns diagonally along the length of therotating portion210a, upwardly toward a distal end of thedeployment mechanism203, rotation of rotatingportion210acauses axial movement ofmember214btoward a distal end of the device. Axial movement ofmember214btoward a distal end of the device results in forward advancement of thepusher component218 within thehollow shaft204. Such movement ofpusher component218 results in partial deployment of theshunt215 from theshaft204.
• FIGS. 21A-21C show schematics of the deployment mechanism at the end of the first stage of deployment of the shunt from the deployment device. As is shownFIG. 21A,members214aand214bhave finished traversing alongfirst portions213a1 and213b1 ofchannels213aand213b. Additionally,pusher component218 has advanced within hollow shaft204 (FIG. 21B), and shunt215 has been partially deployed from the hollow shaft204 (FIG. 21C). As is shown in these figures, a portion of theshunt215 extends beyond an end of theshaft204.
• In the second stage of shunt deployment, the retraction component is engaged and the distal portion of the deployment mechanism is retracted to within the proximal portion of the deployment mechanism, thereby completing deployment of the shunt from the deployment device. During the second stage, rotatingportion210aof theproximal portion210 of thedeployment mechanism203 is further rotated, resulting in movement ofmembers214aand214balongsecond portions213a2 and213b2 inchannels213aand213b. Since thesecond portion213b2 ofchannel213bis straight and runs perpendicular to the length of therotating portion210a, rotation of rotatingportion210adoes not cause axial movement ofmember214b. Without axial movement ofmember214b, there is no further advancement ofpusher component218. Since thesecond portion213a2 ofchannel213aruns diagonally along the length of therotating portion210a, downwardly toward a proximal end of thedeployment mechanism203, rotation of rotatingportion210acauses axial movement ofmember214atoward a proximal end of the device. Axial movement ofmember214atoward a proximal end of the device results in retraction of thedistal portion209 to within theproximal portion210 of thedeployment mechanism203. Retraction of thedistal portion209, results in retraction of thehollow shaft204. Since theshunt215 abuts thepusher component218, the shunt remains stationary as thehollow shaft204 retracts from around the shunt215 (FIG. 21C). Theshaft204 retracts almost completely to within thesleeve205. During both stages of the deployment process, thesleeve205 remains stationary and in a fixed position.
• FIGS. 22A-22D show schematics of thedevice200 after deployment of theshunt215 from thedevice200.FIG. 22B shows a schematic of the deployment mechanism at the end of the second stage of deployment of the shunt from the deployment device. As is shown inFIG. 22B,members214aand214bhave finished traversing alongsecond portions213a1 and213b1 ofchannels213aand213b. Additionally,distal portion209 has retracted to withinproximal portion210, thus resulting in retraction of thehollow shaft204 to within thesleeve205.FIG. 22D shows an enlarged view of the distal portion of the deployment device after deployment of the shunt. This figure shows that thehollow shaft204 is not fully retracted to within thesleeve205 of thedeployment device200. However, in certain embodiments, theshaft204 may completely retract to within thesleeve205.
Methods for Intrascleral Shunt Placement
• Some embodiments of the methods disclosed herein can involve creating an opening in the sclera (e.g., by piercing the sclera with a delivery device), and positioning a shunt in the anterior chamber of the eye such that the shunt terminates adjacent an opening formed in the sclera. In some embodiments, such placement can permit flow through the shunt to reach the intrascleral space, thereby facilitating fluid flow through both the opening and the intrascleral space. The outlet of the shunt may be positioned in different places within the intrascleral space. For example, the outlet of the shunt may be positioned within the sclera (e.g., within deep and superficial layers or tissue of the sclera). Alternatively, the outlet of the shunt may be positioned such that the outlet is even with or superficial to the opening through the sclera.
• Methods of implanting intraocular shunts are known in the art. Shunts may be implanted using an ab externo approach (entering through the conjunctiva and inwards through the sclera) or an ab interno approach (entering through the cornea, across the anterior chamber, through the trabecular meshwork and sclera). The deployment device may be any device that is suitable for implanting an intraocular shunt into an eye. Such devices generally include a shaft connected to a deployment mechanism. In some devices, a shunt is positioned over an exterior of the shaft and the deployment mechanism works to deploy the shunt from an exterior of the shaft. In other devices, the shaft is hollow and the shunt is at least partially disposed in the shaft. In those devices, the deployment mechanism works to deploy the shunt from within the shaft. Depending on the device, a distal portion of the shaft may be sharpened or blunt, or straight or curved.
Ab-Interno Approach
• Ab interno approaches for implanting an intraocular shunt in the subconjunctival space are shown for example in Yu et al. (U.S. Pat. No. 6,544,249 and U.S. Patent Publication No. 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511), the contents of each of which are incorporated by reference herein in its entirety. An exemplary ab-interno method employs a transpupil approach and involves creating a first opening in the sclera of an eye, advancing a shaft configured to hold an intraocular shunt across an anterior chamber of an eye and through the sclera to create a second opening in the sclera, retracting the shaft through the second opening to within the sclera (i.e., the intrascleral space), deploying the shunt from the shaft such that the shunt forms a passage from the anterior chamber of the eye to the intrascleral space of the eye, such that an outlet of the shunt is positioned so that at least some of the fluid that exits the shunt flows through the second opening in the sclera, and withdrawing the shaft from the eye. The first opening in the sclera may be made in any manner. In certain embodiments, the shaft creates the first opening in the sclera. In other embodiments, a tool other than the shaft creates the first opening in the sclera.
• In certain embodiments, some embodiments of the methods disclosed herein can generally involve inserting into the eye a hollow shaft configured to hold an intraocular shunt. In certain embodiments, the hollow shaft is a component of a deployment device that may deploy the intraocular shunt. The shunt is then deployed from the shaft into the eye such that the shunt forms a passage from the anterior chamber into the sclera (i.e., the intrascleral space). The hollow shaft is then withdrawn from the eye.
• To place the shunt within the eye, a surgical intervention to implant the shunt is performed that involves inserting into the eye a deployment device that holds an intraocular shunt, and deploying at least a portion of the shunt within intrascleral space.FIGS. 23-30 provide an exemplary sequence for ab interno shunt placement. In certain embodiments, ahollow shaft109 of a deployment device holding theshunt112 enters the eye through the cornea (ab interno approach,FIG. 23). Theshaft109 is advanced across theanterior chamber110 in what is referred to as a transpupil implant insertion. Theshaft109 is advanced through the anterior angle tissues of the eye and into thesclera8 and further advanced until it passes through thesclera8, thereby forming a second opening in the sclera8 (FIGS. 24-25). Once the second opening in thesclera8 is achieved, theshaft109 is retracted all the way back through thesclera8 and into theanterior chamber110 of the eye (FIGS. 26-29). During this shaft retraction, theshunt112 is held in place by aplunger rod111 that is positioned behind the proximal end of theshunt112. After theshaft109 has been completely withdrawn from thesclera8, theplunger rod111 is withdrawn as well and the shunt implantation sequence is complete (FIG. 30). This process results in an implantedshunt112 in which a distal end of theshunt112 is proximate apassageway114 through thesclera8. Once fully deployed, a proximal end ofshunt112 resides in theanterior chamber110 and a distal end ofshunt112 resides in the intrascleral space. Preferably asleeve113 is used around theshaft112 and designed in length such that thesleeve113 acts as a stopper for the scleral penetration of the shaft and also determines the longitudinal placement of the proximal end of the shunt.
• Insertion of the shaft of the deployment device into thesclera8 produces a long scleral channel of about 2 mm to about 5 mm in length. Withdrawal of the shaft of the deployment device prior to deployment of theshunt112 from the device produces a space in which theshunt112 may be deployed. Deployment of theshunt112 allows foraqueous humor3 to drain into traditional fluid drainage channels of the eye (e.g., the intrascleral vein, the collector channel, Schlemm's canal, the trabecular outflow, and the uveoscleral outflow to the ciliary muscle. The deployment is performed such that an outlet of the shunt is positioned proximate the opening in the sclera so that at least some of the fluid that exits the shunt flows through the opening in the sclera, thereby ensuring that the intrascleral space does not become overwhelmed with fluid output from the shunt.
• FIG. 32 provides an exemplary schematic of a hollow shaft for use in accordance with some embodiments of the methods disclosed herein. This figure shows ahollow shaft122 that is configured to hold anintraocular shunt123. The shaft may hold the shunt within thehollow interior124 of the shaft, as is shown inFIG. 32. Alternatively, the hollow shaft may hold the shunt on anouter surface125 of the shaft. In some embodiments, the shunt is held completely within the hollow interior of theshaft124, as is shown inFIG. 32. In other embodiments, ashunt123ais only partially disposed within ahollow shaft123b, as shown inFIG. 4. Generally, in one embodiment, the intraocular shunts are of a cylindrical shape and have an outside cylindrical wall and a hollow interior. The shunt may have an inside diameter of about 10 μm to about 250 μm, an outside diameter of about 100 μm to about 450 μm, and a length of about 1 mm to about 12 mm. In some embodiments, the shunt has a length of about 2 mm to about 10 mm and an outside diameter of about 150 μm to about 400 μm. Thehollow shaft122 is configured to at least hold a shunt of such shape and such dimensions. However, thehollow shaft122 may be configured to hold shunts of different shapes and different dimensions than those described above, and some embodiments can encompass ashaft122 that may be configured to hold any shaped or dimensioned intraocular shunt.
• Preferably, some embodiments of the methods disclosed herein are conducted by making an incision in the eye prior to insertion of the deployment device. In some embodiments of the methods disclosed herein may be conducted without making an incision in the eye prior to insertion of the deployment device. In certain embodiments, the shaft that is connected to the deployment device has a sharpened point or tip. In certain embodiments, the hollow shaft is a needle. Exemplary needles that may be used are commercially available from Terumo Medical Corp. (Elkington Md.). In some embodiments, the needle has a hollow interior and a beveled tip, and the intraocular shunt is held within the hollow interior of the needle. In another embodiment, the needle has a hollow interior and a triple ground point or tip.
• Some embodiments of the methods disclosed herein are preferably conducted without needing to remove an anatomical portion or feature of the eye, including but not limited to the trabecular meshwork, the iris, the cornea, or aqueous humor. Some embodiments of the methods disclosed herein are also preferably conducted without inducing substantial ocular inflammation, such as subconjunctival blebbing or endophthalmitis. Such methods can be achieved using an ab interno approach by inserting the hollow shaft configured to hold the intraocular shunt through the cornea, across the anterior chamber, through the trabecular meshwork and into the sclera. However, some embodiments of the methods disclosed herein may be conducted using an ab externo approach.
• When some embodiments of the methods disclosed herein are conducted using an ab interno approach, the angle of entry through the cornea as well as the up and downward forces applied to the shaft during the scleral penetration affect optimal placement of the shunt in the intrascleral space. Preferably, the hollow shaft is inserted into the eye at an angle superficial to the corneal limbus, in contrast with entering through or deep to the corneal limbus. For example, the hollow shaft is inserted about 0.25 mm to about 3.0 mm, preferably about 0.5 mm to about 2.5 mm, more preferably about 1.0 mm to about 2.0 mm superficial to the corneal limbus, or any specific value within said ranges, e.g., about 1.0 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about 1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, or about 2.0 mm superficial to the corneal limbus.
• Without intending to be bound by any theory, placement of the shunt farther from the limbus at the exit site, as provided by an angle of entry superficial to the limbus, as well as an S-shaped scleral tunnel (FIG. 31) due to applied up or downward pressure during the scleral penetration of the shaft is believed to provide access to more lymphatic channels for drainage of aqueous humor, such as the episcleral lymphatic network, in addition to the conjunctival lymphatic system.
Ab Externo Approach
• In other embodiments, an ab externo approach is employed. Ab externo implantation approaches are shown for example in Nissan et al. (U.S. Pat. No. 8,109,896), Tu et al. (U.S. Pat. No. 8,075,511), and Haffner et al. (U.S. Pat. No. 7,879,001), the content of each of which is incorporated by reference herein in its entirety. An exemplary ab externo approach avoids having to make a scleral flap. In this preferred embodiment, a distal end of the deployment device is used to make an opening into the eye and into the sclera. For example, a needle is inserted from ab externo through the sclera and exits the anterior angle of the eye. The needle is then withdrawn, leaving a scleral slit behind. A silicone tube with sufficient stiffness is then manually pushed through the scleral slit from the outside so that the distal tube ends distal to the Trabecular Meshwork in the anterior chamber of the eye. Towards the proximal end, the tube exits the sclera, lays on top of it, and connects on its proximal end to a plate that is fixated by sutures to the outside scleral surface far away (>10 mm) from the limbus.
• FIGS. 33-39 describes another ab externo method that uses a deployment device. In this method, a distal portion of the deployment device includes ahollow shaft109 that has a sharpened tip (FIG. 33). Ashunt112 resides within theshaft109. Thedistal shaft109 is advanced into the eye and into thesclera8 until a proximal portion of the shaft resides in theanterior chamber110 and a distal portion of theshaft109 is inside the scleral8 (FIGS. 34-36). Deployment of theshunt112 that is located inside theshaft109 is then accomplished by a mechanism that withdraws theshaft109 while theshunt112 is held in place by aplunger111 behind the proximal end of the shunt112 (FIGS. 37-39). As the implantation sequence progresses, theshaft109 is completely withdrawn from thesclera8. After that, theplunger111 is withdrawn from thesclera8, leaving theshunt112 behind with its distal end inside thesclera8, its proximal end inside theanterior chamber110, and apassageway114 through thesclera8. In a preferred embodiment theshaft109 is placed inside asleeve113 that is dimensioned in length relative to theshaft109 such that it will act as stopper during the penetration of theshaft109 into the eye and at the same time assures controlled longitudinal placement of theshunt112 relative to the outer surface of the eye. Thesleeve113 may be beveled to match the anatomical angle of the entry site surface.
• The shaft penetrates the conjunctival layer before it enters and penetrates the sclera. This causes a conjunctival hole that could create a fluid leakage after the shunt placement has been completed. To minimize the chance for any leakage, a small diameter shaft is used that results in a self-sealing conjunctival wound. To further reduce the chance for a conjunctival leak, a suture can be placed in the conjunctiva around the penetration area after the shunt placement.
• Furthermore the preferred method of penetrating the conjunctiva is performed by shifting the conjunctival layers from posterior to the limbus towards the limbus, using e.g. an applicator such as a Q-tip, before the shaft penetration is started. This is illustrated inFIGS. 40-41. That figure shows that anapplicator157 is put onto theconjunctiva158, about 6 mm away from the limbus. The loose conjunctiva layer is then pushed towards the limbus to create folding tissue layers that are about 2 mm away from the limbus. Thedevice shaft109 is now inserted through the conjunctiva andsclera8 starting about 4 mm away from the limbus. After the shunt placement has been completed, the Q-tip is released and the conjunctival perforation relaxes back from about 4 mm to about 8 mm limb at distance. This can cause the conjunctival perforation to be 4 mm away from the now slowly starting drainage exit. This distance will reduce any potential for leakage and allows for a faster conjunctival healing response. Alternative to this described upward shift, a sideway shift of the conjunctiva or anything in between is feasible as well. In another embodiment of the ab externo method, a conjunctival slit is cut and the conjunctiva is pulled away from the shaft entry point into the sclera. After the shunt placement is completed, the conjunctival slit is closed again through sutures.
• In certain embodiments, since the tissue surrounding the trabecular meshwork is optically opaque, an imaging technique, such as ultrasound biomicroscopy (UBM), optical coherence tomography (OCT) or a laser imaging technique, can be utilized. The imaging can provide guidance for the insertion of the deployment device and the deployment of the shunt. This technique can be used with a large variety of shunt embodiments with slight modifications since the trabecular meshwork is punctured from the scleral side, rather than the anterior chamber side, in the ab externo insertion.
• In another ab externo approach, a superficial flap may be made in the sclera and then a second deep scleral flap may be created and excised leaving a scleral reservoir under the first flap. Alternatively, a single scleral flap may be made with or without excising any portion of the sclera.
• A shaft of a deployment device is inserted under the flap and advanced through the sclera and into an anterior chamber. The shaft is advanced into the sclera until a proximal portion of the shaft resides in the anterior chamber and a distal portion of the shaft is in proximity to the trabecular outflow. The deployment is then performed such that an outlet of the shunt is positioned proximate the second opening in the sclera so that at least some of the fluid that exits the shunt flows through the first opening in the sclera, thereby ensuring that the intrascleral space does not become overwhelmed with fluid output from the shunt. At the conclusion of the ab externo implantation procedure, the scleral flap may be sutured closed. The procedure also may be performed without suturing.
• Regardless of the implantation method employed, some embodiments of the methods disclosed herein recognize that the proximity of the distal end of the shunt to the scleral exit slit affects the flow resistance through the shunt, and therefore affects the intraocular pressure in the eye. For example, if the distal end of theshunt112 is flush with the sclera surface then there is no scleral channel resistance (FIG. 42). In this embodiment, total resistance comes from theshunt112 alone. In another embodiment, if the distal end of theshunt112 is about 200 μm to about 500 μm behind the scleral exit, then the scleral slit closes partially around the exit location, adding some resistance to the outflow of aqueous humor (FIG. 43). In another embodiments, if the distal end of theshunt112 is more than about 500 micron behind the scleral exit, than the scleral slit closes completely around the exit location with no backpressure and opens gradually to allow aqueous humor to seep out when the intraocular pressure raises e.g. above 10 mmHg (FIG. 44). The constant seepage of aqueous humor keeps the scleral slit from scaring closed over time.
• Effectively, shunt placement according to some embodiments of the methods disclosed herein achieve a valve like performance where the scleral slit in front of the distal shunt end acts like a valve. The opening (cracking) pressure of this valve can be adjusted by the outer shunt diameter and its exact distal end location relative to the scleral exit site. Typical ranges of adjustment are 1 mmHg to 20 mmHg. This passageway distance can be controlled and adjusted through the design of the inserting device as well as the shunt length and the deployment method. Therefore a specific design can be chosen to reduce or prevent hypotony (<6 mmHg) as a post-operative complication.
• FIGS. 45-51 illustrates placement of a shunt in various locations of the eye, according to some embodiments. In these figures, the first end of a shunt is positioned in the region of lower pressure and a second end of the shunt is positioned in a region of high pressure. For example, inFIG. 45, an end of ashunt300 is shown extending into theanterior chamber1.
• According to some embodiments of the methods disclosed herein, the shunt can access the region of lower pressure by extending through the anterior chamber angle tissue. Thus, whether the shunt is targeting supraciliary space, suprachoroidal space, the intrascleral space, intra-Tenon's adhesion space, or subconjunctival space, the shunt can be placed through the anterior chamber angle tissue.
• FIG. 45 illustrates supraciliary placement of ashunt300. As shown, theshunt300 extends from theanterior chamber1 to thesupraciliary space310.FIG. 46 illustrates suprachoroidal placement of ashunt320. As shown, theshunt320 extends from theanterior chamber1 to asuprachoroidal space322. As discussed above, thesupraciliary space310 can be continuous with thesuprachoroidal space322.
• FIG. 47 illustrates subconjunctival placement of ashunt330. As shown, theshunt330 extends from theanterior chamber1 to thesubconjunctival space332.FIG. 48 illustrates intrascleral placement of ashunt340. As shown, theshunt340 extends from theanterior chamber1 to theintrascleral space342.
• FIG. 49 depicts placement of ashunt350 in theintra-Tenon's adhesion space11 of Tenon'scapsule10, according to some embodiments. As shown, theshunt350 extends from theanterior chamber1 to theintra-Tenon's adhesion space11. Theshunt350 can be passed through thesclera8. In some embodiments, theshunt350 can extend at least partially through Schlemm'scanal30 and/or thetrabecular meshwork32. Further, theshunt350 can extend through thetrabecular meshwork32 without passing through Schlemm'scanal30. Furthermore, theshunt350 can extend entirely through thesclera8 without passing through Schlemm'scanal30 or thetrabecular meshwork32. This may be accomplished by passing through the sclera in a location posterior to Schlemm'scanal34 anterior to thetrabecular meshwork32, above thescleral spur36. In accordance with some embodiments, theshunt350 can access theintra-Tenon's adhesion space11 in a location anterior to therectus muscle20. For example, a distal end of theshunt350 can be positioned between the layers ofintra-Tenon's adhesion space11 anterior to therectus muscle20.
• FIG. 50 is an enlarged schematic cross-sectional view taken along section lines50-50 ofFIG. 49. As illustrated inFIG. 50, theshunt350 extends through theintra-Tenon's adhesion space11. As shown, theintra-Tenon's adhesion space11 comprises spongy, porous tissue (adhesions352) that can facilitate drainage of aqueous humor from the anterior chamber.
• When placing theshunt350 into theintra-Tenon's adhesion space11, some embodiments of the methods disclosed herein can comprise accessing theintra-Tenon's adhesion space11 by inserting a needle through adeep layer360 of Tenon'scapsule10 and positioning adistal end362 of theshunt350 into theintra-Tenon's adhesion space11.
• For example, theshunt350 can enterintra-Tenon's adhesion space11 and, while maintaining the position of the needle (to avoid further advancement of the needle into the intra-Tenon's adhesion space11), theshunt350 can then be urged distally into theintra-Tenon's adhesion space11 in order to preserve theadhesions352 that extend between asuperficial layer370 and thedeep layer360 of the Tenon'scapsule10.
• In some embodiments, when thedeep layer360 is pierced, theshunt350 can be at least partially exposed beyond a distal tip of a needle and urged distally using a pusher component such that the shunt moves distally out of the needle while maintaining the needle in a generally stationary position. For example,FIG. 51 illustrates that thedistal end362 of theshunt350 can be urged distally such that thedistal end362 passes betweenadjacent adhesions352, which may cause theshunt350 to deflect, bend, and/or curve within theintra-Tenon's adhesion space11. Embodiments of such methods can thus be performed to allow non-destructive access to theintra-Tenon's adhesion space11.
Deployment Device Motion Sequences
• According to some embodiments, the deployment device can be operated to release a shunt within the eye using a variety of motion sequences. The motion sequences can be performed manually or automatically, with a device. In some embodiments of the sequences discussed below, the operator or clinician can perform a procedure using only two discrete motions: advancing the device into the eye until reaching a final stop position and then, after the shunt has been implanted into the tissue, retracting the device from the eye. However, in accordance with some embodiments of the sequences discussed below, the operator or clinician can also exert a rotational force on one or more components of the device or on the device as a whole, to control advancement and release of the shunt. Further, in some embodiments of the sequences discussed below, the operator or clinician can perform the procedure using more than two discrete axial motions, such as: advancing the device into the eye until reaching a preliminary stop position, and while implanting the shunt into the tissue, advancing the device toward a final stop position; thereafter, when the shunt is implanted into the tissue, the device can be proximally withdrawn from the tissue. Additionally, in some embodiments of the sequences discussed below, the operator or clinician can exert axial and rotational forces on the device to facilitate placement and release of the shunt.
• Various procedures for releasing a shunt into the eye are discussed below with respect toFIGS. 52A-54E and aspects of this discussion can be applied to more than one of the embodiments of the procedures discussed herein. Such procedures allow a clinician to use a deployment device to place the shunt precisely within the eye while minimizing any trauma to the surrounding eye tissue.
• As shown,FIGS. 52A-52E illustrate placement of a shunt into the subconjunctival space. However, as discussed herein, the desired location can be one of various anatomical locations within the eye, including, but not limited to the intrascleral space, the subconjunctival space, and/or the intra-Tenon's adhesion space. According to some embodiments, the shunt can be positioned such that one or more drainage outlets of the shunt extends within one or more anatomical locations within the eye, such as a single anatomical location, or across multiple anatomical locations, thereby providing drainage to either a single or multiple locations.
• Further, according to some embodiments, the deployment device can comprise a shaft that has a hard tip (e.g., to pierce the sclera for placing the shunt, e.g., in the intrascleral space, the subconjunctival space, and/or the intra-Tenon's adhesion space) or a softer tip (e.g., to advance the shunt, e.g., for placing the shunt in the supraciliary space and/or suprachoroidal space). Thus, although the embodiments illustrated inFIGS. 52A-55E illustrate that placement of a shunt can be through or in sclera, other embodiments of an implantation procedure can be performed such that the shunt is placed deep to a deep layer of the sclera.
• According to some embodiments, a shunt can be loaded into the shaft such that a distal end portion of the shunt is positioned at the distal end of the shaft410 (see e.g.,FIGS. 23-30 andFIGS. 33-41).
• FIGS. 52A-52E illustrate steps of a method in which adeployment device400 can be inserted into theeye402 and provide a visual indication or guide for an operator during shunt placement. Thedevice400 can be advanced across theanterior chamber404 of theeye402 until a needle orshaft410 of thedevice400 pierces the tissue at theanterior chamber angle412, referred to as anterior chamber angle tissue. Thedevice400 can also comprise asleeve414 having a lumen in which theshaft410 is disposed. Thesleeve414 can comprise adistal end416 that can be visible within theanterior chamber404 of theeye402. According to some embodiments, a mark or reference point on thesleeve414, for example, thedistal end416 of thesleeve414, can provide a visual indication or guide for an operator during placement of the shunt, so as to locate or assess a final longitudinal position of the shunt.
• For example, in some embodiments, such as those illustrated inFIGS. 52A-52E and 54A-54E, thedeployment device400 can be configured such that when the shunt is being released from thedevice400, a pusher component or plunger of thedevice400 can distally advance the shunt relative to theshaft410 until the proximal end of the shunt is approximately longitudinally adjacent to thedistal end416 of thesleeve414. Thus, after the pusher component has been advanced to a desired position (e.g., to a position in which a distal end of the pusher component is proximal to, coextensive with, or distal to a distal end of the shaft410) within theshaft410, proximal retraction of the shaft410 (while maintaining thesleeve414 in a desired location) will release the shunt from thedevice400 with the proximal end of the shunt being finally positioned about where thedistal end416 of thesleeve414 is positioned. While the relative positions of thedistal end416 of thesleeve414 and the fully extended pusher component can vary according to some embodiments (e.g., contrast the embodiment shown inFIGS. 53A-53E), the visualization of the position of the distal end416 (or another marked aspect of the sleeve414) can facilitate precise longitudinal placement of the shunt within the eye tissue.
• According to some embodiments, the mark or reference point of thesleeve414 can comprise thedistal end416 or a line extending crosswise on the sleeve414 (proximal to the distal end416). The mark or reference point can comprise a high contrast element or color to facilitate visualization or discernment of the location of the marker reference point when thesleeve414 is inserted into or toward an aspect of the eye, such as theanterior chamber404 oranterior chamber angle412.
• Further, although a clinician can, in some embodiments, verify initial placement of thedevice400 with reference only to a mark, reference point, or position of thedistal end416 of thesleeve414 relative to an aspect of the eye, such as the anterior chamber angle tissue oranterior chamber angle412 itself, the initial placement or position of thedevice400 can also be based on the position of theshaft410 within the eye tissue. For example, for subconjunctival placement of theshunt420, as theshaft410 is advanced through the sclera, abevel418 of theshaft410 will eventually be seen through the conjunctiva (which is translucent) as thebevel418 exits the sclera. The clinician, based on the visual confirmation of the location of the bevel below418 the conjunctiva, can thereby determine that theshaft410 has been advanced sufficiently. To avoid further advancement, which could result in piercing or damaging the conjunctiva, the clinician can use thedistal end416 of thesleeve414 to provide a visual indication or guide whereby the clinician can maintain the position of thedevice400 steady within the eye. Thus, thebevel418 can be maintained in a position adjacent to or opening to the subconjunctival space.
• In some embodiments, such as that illustrated inFIGS. 52A-52E, as thedevice400 is moved through theanterior chamber404 and into initial position within the eye tissue, theshaft410 can be positioned relative to thesleeve414 such that thebevel418 is spaced about 3 mm to about 7 mm, about 4 mm to about 6 mm, or about 5 mm from thedistal end416 of thesleeve414. Such spacing can allow thedistal end416 of thesleeve414 to be spaced apart from the anterior chamber angle tissue when thebevel418 emerges from the sclera to become visible under the conjunctiva. Thus, the clinician can advantageously confirm proper initial placement of thedevice400 by verifying bevel emergence from the sclera if it would otherwise be difficult to visually verify a relative positioning of thedistal end416 of thesleeve414 and the anterior chamber angle tissue oranterior chamber angle412. This provides freedom to allow for variability in the anatomy and/or trajectory of the advancing shaft410 (e.g., for differences in the thickness of sclera from patient to patient).
• After thedevice400 has been advanced through theanterior chamber404 and the needle orshaft410 has pierced the anterior chamber angle tissue at theanterior chamber angle412, theshunt420 can be advanced such that adistal end portion422 of theshunt420 is moved into or positioned at a desired location within the eye402 (here shown as the subconjunctival space430).
• The advancement of thedistal end portion422 of theshunt420 into the desired location of theeye402 can be performed by advancing the pusher component (not shown) relative to theshaft410 while maintaining theshaft410 and thesleeve414 steady, at a generally constant position or location, until thedistal end portion422 has been fully advanced into the desired location, as illustrated inFIGS. 52B-52C. Thereafter, as shown inFIG. 52D, theshaft410 can be proximally withdrawn relative to theshunt420. In some embodiments, theshaft410 can also be proximally withdrawn relative to thesleeve414 and the pusher component while maintaining thesleeve414 steady, at a generally constant position or location relative to the tissue. As theshaft410 is proximally withdrawn from the tissue of theeye402, the pusher component maintains the longitudinal position of theshunt420 in order to ensure that thedistal end portion422 remains embedded at the desired location. Accordingly, proximal withdrawal of theshaft410, while maintaining the position of theshunt420 in theeye402, allows further exposure of theshunt422 surrounding tissue.
• Eventually, after theshunt420 is released or embedded within the eye tissue, theshaft410 can be fully withdrawn from covering or enclosing theshunt420, as shown inFIG. 52E. Further, in some embodiments, theshaft410 can be completely retracted into the lumen of thesleeve414, as also illustrated inFIG. 52E. Theshaft410 and the pusher component can be further withdrawn or retracted together into the lumen of thesleeve414, as necessary. Thereafter, thedevice400 can be proximally withdrawn from theeye402 and the procedure can be completed.
• In accordance with some embodiments, thedevice400 can also deliver theshunt420 by allowing thedistal end416 of thesleeve414 to contact or abut tissue within the eye. For example, thedistal end416 of thesleeve414 can comprise one or more blunt structures, such as an edge, protrusion, and/or an annular, enlarged portion, that can be abutted with tissue of theeye402, such as the anterior chamber angle tissue.
• For example, referring toFIGS. 53A-53E, after thedevice400 is advanced into theanterior chamber404, as discussed above with respect toFIG. 52A, the needle orshaft410 can pierce the anterior chamber angle tissue. According to some embodiments, thedevice400 can be advanced until thedistal end416 of theshaft414 abuts the anterior chamber angle tissue of theanterior chamber angle412. This abutment can provide resistance feedback to an operator, indicating that no further advancement of thedevice400 is necessary. As discussed herein, thedevice400 can comprise a blunt structure to prevent theshaft410 from accidentally being pushed too far through the eye tissue.
• In some embodiments, such as that illustrated inFIGS. 53A-53E, as thedevice400 is moved through theanterior chamber404 and into initial position within the eye tissue, theshaft410 can be positioned relative to thesleeve414 such that thebevel418 is spaced about 2 mm to about 6 mm, about 3 mm to about 5 mm, or about 4 mm from thedistal end416 of thesleeve414. Such spacing can tend to ensure that thedistal end416 of thesleeve414 is able to contact the anterior chamber angle tissue as thebevel418 emerges from the sclera, but avoid piercing of the sclera.
• Once thedistal end416 of thesleeve414 is positioned abutting the tissue of theeye402, theshunt420 can be advanced distally, e.g., by using a pusher component (not shown), until adistal end portion430 of theshunt420 is positioned at the desired location, as shown inFIG. 53C. In some embodiments, such as that shown inFIGS. 53A-53E, the position of thedistal end416 of thesleeve414 relative to the fully extended pusher component can be configured such that a maximum distal displacement or maximum distal position of the pusher component is longitudinally proximal to the sleevedistal end416 when the pusher component is advanced within the shaft (see alsoFIGS. 23-30). For example, the pusher component can have a distalmost position of between about 0 mm and about 8 mm, about 0 mm and about 4 mm, about 0 mm and about 2 mm, or about 0 mm and about 1 mm proximal to the sleeve distal end.
• Thereafter, once theshunt420 is advanced to its final position, as shown inFIG. 53D, theshaft410 can be proximally withdrawn relative to thesleeve414 to further expose theshunt420 to surrounding tissue. Additionally, as shown inFIG. 53E, and as discussed above, theshaft410 can be fully withdrawn into thesleeve414. Finally, thedevice400 can be removed from the eye and the procedure can be completed.
• Further, in the embodiment illustrated inFIGS. 54A-54E, thedevice400 can be advanced through theanterior chamber404 and theshaft410 can pierce and enter eye tissue. Thedevice400 can be advanced until adistal end416 of thesleeve414 is positioned adjacent to or spaced apart from, but not abutting, the anterior chamber angle tissue or is positioned within the anterior chamber angle412 (a similar initial position to that ofFIG. 52B). Such a position can be a preliminary stop position, as mentioned above, at which the clinician can cease advancement of thedevice400.
• In such embodiments, after thedevice400 has been initially placed in the anterior chamber angle tissue oranterior chamber angle412, theshunt420 can be released by a motion sequence in which theshaft410 is maintained steady within the tissue while thedistal end416 of thesleeve414 is advanced to abut the anterior chamber angle tissue, as discussed below. Such a motion can, in some embodiments, require that the operator or clinician further advance thedevice400 axially until reaching a final stop position, achieved when thedistal end416 of thesleeve414 abuts the anterior chamber angle tissue. However, thedevice400 can also be configured to allow thesleeve414 to move relative to a housing of the device, thereby allowing the operator or clinician to maintain thedevice400 stationary relative to the face of the patient as thesleeve414 is advanced further toward the anterior chamber angle tissue.
• As illustrated inFIGS. 54A-54B, thedevice400 initially enters theanterior chamber404 and is advanced until theshaft410 pierces the anterior chamber angle tissue. Thedistal end416 of thesleeve414 can be maintained or held spaced apart from the eye tissue oranterior chamber angle412, at an initial placement or position such as that discussed above with respect toFIG. 52B. Although a clinician can, in some embodiments, verify initial placement of thedevice400 with reference only to the position of thedistal end416 of thesleeve414 relative to the anterior chamber angle tissue oranterior chamber angle412, the initial placement or position of thedevice400 can also be based on the position of theshaft410 within the eye tissue.
• For example, as similarly discussed above, for subconjunctival placement of theshunt420, the shaft410 (and hence, the sleeve414) will be at its proper location when abevel418 of theshaft410 has exited or emerged from the sclera, but has not penetrated the conjunctiva. This emergence can be visually verified because thebevel418 can be seen through or below the conjunctiva (which is translucent). Thereafter, the position of thedevice400 within theeye402 can be maintained steady such that thebevel418 remains positioned adjacent to or opening to the subconjunctival space.
• In such embodiments, such as that illustrated inFIGS. 54A-54E, as thedevice400 is moved through theanterior chamber404 and into initial position within the eye tissue, theshaft410 can be positioned relative to thesleeve414 such that thebevel418 is spaced about 1 mm to about 5 mm, about 2 mm to about 4 mm, or about 3 mm from thedistal end416 of thesleeve414. Such spacing can allow thedistal end416 of thesleeve414 to be spaced apart from the eye tissue oranterior chamber angle412 when thebevel418 emerges from the sclera. Thus, the clinician can advantageously confirm proper initial placement of thedevice400 by verifying bevel emergence from the sclera if it would otherwise be difficult to visually verify a relative positioning of thedistal end416 of thesleeve414 and the tissue oranterior chamber angle412. This provides freedom to allow for variability in the anatomy and/or trajectory of the advancingshaft410.
• Once initial placement of thedevice400 is proper, the motion sequence can continue by initiating relative movement between theshaft410, thesleeve414, and pusher component (not shown) to begin releasing theshunt420.
• As illustrated inFIGS. 54C-54D, after thedevice400 reaches the initial position, theshunt420 can be distally advanced into the tissue until adistal end portion430 reaches the desired location. The advancement of thedistal end portion422 of theshunt420 into the desired location of theeye402 can be performed by advancing the pusher component (not shown) relative to theshaft410 while maintaining theshaft410 and thesleeve414 steady, at a generally constant position or location.
• Further, as illustrated inFIG. 54D, theshaft410 can be proximally withdrawn into thesleeve414. However, instead of maintaining thesleeve414 at a generally constant position or location relative to the eye while theshaft410 is withdrawn into the sleeve414 (and in contrast to the embodiments discussed inFIGS. 52A-53E), theshaft410 can be obtained at a generally constant position relative to the eye tissue while thesleeve414 moves relative to the eye tissue.
• For example, the relative movement between thesleeve414 and theshaft410 while theshaft410 remains at a constant position relative to the eye tissue causes thesleeve414 to be longitudinally advanced along theshaft410, distally toward the eye tissue oranterior chamber angle412. Thus, thesleeve414 can move while theshaft410 is held steady in the eye, at a generally constant position or location within the tissue. Accordingly, thesleeve414 will be distally advanced toward theanterior chamber angle412 until thedistal end416 of thesleeve414 contacts or abuts the eye tissue, such as the anterior chamber angle tissue.
• In some embodiments, thesleeve414 can be advanced distally along theshaft410 by about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, or more, as necessary, until contacting eye tissue.
• For example, the sleevedistal end416 can be distally advanced between about 1 mm to about 4 mm or between about 2 mm to about 3 mm. The sleeve can be advanced at a rate of between about 0.15 mm/sec to about 0.85 mm/sec, and in some embodiments, between about 0.25 mm/sec to about 0.65 mm/sec.
• When thedistal end416 abuts the eye tissue, further relative retraction of theshaft410 into thesleeve414 will cause theshaft410 to be proximally withdrawn from the tissue because thedistal end416 of thesleeve414 has now abutted the anterior chamber angle tissue, as illustrated inFIGS. 54D-54E. Continued retraction or withdrawal of theshaft410 can cause theshaft410 to be fully withdrawn into the lumen of thesleeve414.
• Aspects of the procedures discussed herein, including those discussed with respect toFIGS. 52A-54E, can be implemented in various embodiments of a procedure for implanting an intraocular shunt. The deployment device can operate according to the features of any of the embodiments disclosed herein.
• In any of the procedures discussed above with respectFIGS. 52A-54E, when thebevel418 has been advanced through the sclera toward the subconjunctival space, it may be necessary to further actuate thebevel418 in order to ensure that the subconjunctival space has been reached and can be easily accessed by the shunt.
• First, some clinicians may tend to conservatively advance thebevel418 within the sclera and fail to reach the subconjunctival space such that thebevel418 is placed between the sclera and the conjunctiva. In such situations, when thebevel418 has been advanced to a position shy of the subconjunctival space within the sclera, thebevel418 can be rotated within the sclera to permit thebevel418 to “crack” the sclera and ensure that the subconjunctival space has been accessed. The rotation of thebevel418 can cause the oblong or oval shape of thebevel418 to rotate from a flat position to an upright position, thereby pushing, breaking, or otherwise breaching the top surface of the sclera so that the lumen of theshaft410 opens to the subconjunctival space to allow theshunt420 to be advanced therefrom.
• Second, in order to ensure that the subconjunctival space can be easily accessed by the shunt, even when the sclera has been breached in the subconjunctival space has been accessed, rotating thebevel418 can cause the conjunctiva to become “tented” or spaced apart from the top surface of the sclera. This “tenting” of the conjunctiva can create a pocket within the subconjunctival space. When advancing theshunt420, the pocket will provide little frictional resistance or threat of impeding travel of theshunt420 within the subconjunctival space. Accordingly, theshunt420 can more readily begin its entry into the subconjunctival space, thus avoiding kinking or bending of theshunt420 due to high frictional resistance that would otherwise be present absent the creation of the pocket within the subconjunctival space.
• Further teachings regarding the rotation or actuation of thebevel418 within the sclera are disclosed in Applicant's copending U.S. patent application Ser. No. 12/946,556, filed Nov. 15, 2010, the entirety of which is incorporated herein by reference.
• Further, the relative positioning of a shunt within the shaft and the range of movement of the pusher component within the shaft can be selectively modified to optimize the position of the shunt end portions when performing the motion sequences of the deployment device. In particular, to ensure proper placement of the distal end portion of the shunt, the maximum distal or fully advanced position of the pusher component relative to the sleeve distal end can be optimized.
• For example, as noted above, the pusher component can have a maximum distal displacement or maximum distal position that results in the pusher component being positioned at least longitudinally adjacent to (longitudinally coextensive with) the sleeve distal end or distally beyond the sleeve distal end when the distal end of the sleeve distal end is maintained spaced apart from the eye tissue (e.g., spaced apart from the anterior chamber angle tissue), when the pusher component is advanced within the shaft (seeFIGS. 33-41,FIGS. 52B-52C, andFIGS. 54B-54C). For example, the pusher component can have a distalmost position of between 0 mm and about 8 mm, about 0 mm and about 4 mm, about 0 mm and about 2 mm, or about 0 mm and about 1 mm beyond or distal to the sleeve distal end.
• Further, as noted above, the pusher component can have a maximum distal displacement or maximum distal position that results in the pusher component being positioned longitudinally proximal to the sleeve distal end when the pusher component is advanced within the shaft (seeFIGS. 23-30 andFIGS. 53B-53C). For example, the pusher component can have a distalmost position of between about 0 mm and about 8 mm, about 0 mm and about 4 mm, about 0 mm and about 2 mm, or about 0 mm and about 1 mm proximal to the sleeve distal end.
• The foregoing description is provided to enable a person skilled in the art to practice the various configurations described herein. While the subject technology has been particularly described with reference to the various figures and configurations, it should be understood that these are for illustration purposes only and should not be taken as limiting the scope of the subject technology.
• There may be many other ways to implement the subject technology. Various functions and elements described herein may be partitioned differently from those shown without departing from the scope of the subject technology. Various modifications to these configurations will be readily apparent to those skilled in the art, and generic principles defined herein may be applied to other configurations. Thus, many changes and modifications may be made to the subject technology, by one having ordinary skill in the art, without departing from the scope of the subject technology.
• It is understood that the specific order or hierarchy of steps in the processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. Some of the steps may be performed simultaneously. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
• Terms such as “top,” “bottom,” “front,” “rear” and the like as used in this disclosure should be understood as referring to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. Thus, a top surface, a bottom surface, a front surface, and a rear surface may extend upwardly, downwardly, diagonally, or horizontally in a gravitational frame of reference.
• Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim.
• The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
• A reference to an element in the singular is not intended to mean “one and only one” unless specifically stated, but rather “one or more.” Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. The term “some” refers to one or more. Underlined and/or italicized headings and subheadings are used for convenience only, do not limit the subject technology, and are not referred to in connection with the interpretation of the description of the subject technology. All structural and functional equivalents to the elements of the various configurations described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the subject technology. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the above description.
• While certain aspects and embodiments of the inventions have been described, these have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms without departing from the spirit thereof. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims (20)

1. A method of treating glaucoma comprising determining an entry area below a corneal limbus of an eye and inserting an intraocular shunt into eye tissue through the entry area such that an inflow end of the shunt is positioned in the anterior chamber of the eye and an outflow end of the shunt is positioned adjacent to Tenon's capsule.

2. The method ofclaim 1, wherein inserting an intraocular shunt into eye tissue comprises forming a passageway through the sclera.

3. The method ofclaim 1, wherein a device for deploying the intraocular shunt comprises a shaft configured to hold the shunt, and wherein the inserting comprises advancing the shaft through the sclera until reaching a first position at which a bevel of the shaft is positioned in the anterior chamber of the eye.

4. The method ofclaim 3, wherein after reaching the first position, the inserting comprises advancing a pusher component of the device such that the shunt is pushed distally out of the shaft.

5. The method ofclaim 4, wherein the advancing the pusher component comprises pushing less than an entire length of the shunt distally out of the shaft.

6. The method ofclaim 4, wherein the device comprises a sleeve having a distal end and a lumen, the shaft being disposed within the lumen, wherein the inserting further comprises advancing the pusher component to a distal most position at which a distal end of the pusher component is positioned longitudinally proximal to the sleeve distal end.

7. The method ofclaim 4, wherein the device comprises a sleeve having a distal end and a lumen, the shaft being disposed within the lumen, and wherein at the first position, the sleeve distal end is spaced apart from the eye tissue.

8. The method ofclaim 7, wherein the inserting further comprises advancing the pusher component until a distal end of the pusher component is positioned longitudinally adjacent to the sleeve distal end.

9. The method ofclaim 7, wherein the sleeve distal end is spaced apart from anterior chamber angle tissue in the first position.

10. The method ofclaim 7, wherein the inserting further comprises, while maintaining the shaft substantially fixed relative to the sclera, advancing the sleeve distally over the shaft until the sleeve distal end contacts eye tissue.

11. The method ofclaim 10, wherein after the sleeve distal end contacts the eye tissue, the inserting further comprises proximally withdrawing the shaft from the sclera until the bevel is received within a lumen of the sleeve.

12. The method ofclaim 4, wherein the device comprises a sleeve having a distal end comprising a beveled shape that corresponds with an anatomical angle of the entry area surface of the eye.

13. A method of treating glaucoma comprising determining an entry area posterior to a corneal limbus of an eye and inserting an intraocular shunt into eye tissue through the entry area such that first end of the shunt is positioned in the anterior chamber of the eye and a second end of the shunt is positioned between layers of Tenon's capsule.

14. The method ofclaim 13, wherein a device for deploying the intraocular shunt comprises a shaft configured to hold the shunt, and wherein the inserting comprises advancing the shaft through the sclera until reaching a first position at which a distal end of the shaft is positioned in the anterior chamber of the eye.

15. The method ofclaim 14, wherein after reaching the first position, the inserting comprises advancing a pusher component of the device such that the shunt is pushed distally out of the shaft.

16. The method ofclaim 15, wherein the advancing the pusher component comprises pushing less than an entire length of the shunt distally out of the shaft.

17. An ab externo intraocular shunt insertion technique wherein the shunt enters an eye via the sclera and is positioned so as to extend from the anterior chamber of the eye to a region between layers of Tenon's capsule.

18. The method ofclaim 17, wherein a device for deploying the intraocular shunt comprises a shaft configured to hold the shunt, and wherein the inserting comprises advancing the shaft through the sclera until reaching a first position at which a distal end of the shaft is positioned in the anterior chamber of the eye.

19. The method ofclaim 18, wherein after reaching the first position, the inserting comprises advancing a pusher component of the device such that the shunt is pushed distally out of the shaft.

20. The method ofclaim 19, wherein the advancing the pusher component comprises pushing less than an entire length of the shunt distally out of the shaft.

Images