US20090082862A1 - Ocular Implant Architectures - Google Patents

Abstract

An ocular implant having a first spine; a second spine; a first strut extending in an axial direction Z between the first spine and the second spine; a second strut extending in an axial direction Z between the first spine and the second spine; wherein an angular dimension θ of a first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is a continuation-in-part of U.S. application Ser. No. 11/860,318, filed Sep. 24, 2007, and claims priority to U.S. Provisional Application No. 61/033,746, filed Mar. 4, 2008, the disclosures of which are incorporated by reference as if fully set forth herein.
INCORPORATION BY REFERENCE
• All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
FIELD OF THE INVENTION
• The present invention relates generally to devices that are implanted within the eye. More particularly, the present invention relates to devices that facilitate the transfer of fluid from within one area of the eye to another area of the eye.
BACKGROUND OF THE INVENTION
• According to a draft report by The National Eye Institute (NEI) at The United States National Institutes of Health (NIH), glaucoma is now the leading cause of irreversible blindness worldwide and the second leading cause of blindness, behind cataract, in the world. Thus, the NEI draft report concludes, “it is critical that significant emphasis and resources continue to be devoted to determining the pathophysiology and management of this disease.” Glaucoma researchers have found a strong correlation between high intraocular pressure and glaucoma. For this reason, eye care professionals routinely screen patients for glaucoma by measuring intraocular pressure using a device known as a tonometer. Many modern tonometers make this measurement by blowing a sudden puff of air against the outer surface of the eye.
• The eye can be conceptualized as a ball filled with fluid. There are two types of fluid inside the eye. The cavity behind the lens is filled with a viscous fluid known as vitreous humor. The cavities in front of the lens are filled with a fluid know as aqueous humor. Whenever a person views an object, he or she is viewing that object through both the vitreous humor and the aqueous humor.
• Whenever a person views an object, he or she is also viewing that object through the cornea and the lens of the eye. In order to be transparent, the cornea and the lens can include no blood vessels. Accordingly, no blood flows through the cornea and the lens to provide nutrition to these tissues and to remove wastes from these tissues. Instead, these functions are performed by the aqueous humor. A continuous flow of aqueous humor through the eye provides nutrition to portions of the eye (e.g., the cornea and the lens) that have no blood vessels. This flow of aqueous humor also removes waste from these tissues.
• Aqueous humor is produced by an organ known as the ciliary body. The ciliary body includes epithelial cells that continuously secrete aqueous humor. In a healthy eye, a stream of aqueous humor flows out of the anterior chamber of the eye through the trabecular meshwork and into Schlemm's canal as new aqueous humor is secreted by the epithelial cells of the ciliary body. This excess aqueous humor enters the venous blood stream from Schlemm's canal and is carried along with the venous blood leaving the eye.
• When the natural drainage mechanisms of the eye stop functioning properly, the pressure inside the eye begins to rise. Researchers have theorized prolonged exposure to high intraocular pressure causes damage to the optic nerve that transmits sensory information from the eye to the brain. This damage to the optic nerve results in loss of peripheral vision. As glaucoma progresses, more and more of the visual field is lost until the patient is completely blind.
• In addition to drug treatments, a variety of surgical treatments for glaucoma have been performed. For example, shunts were implanted to direct aqueous humor from the anterior chamber to the extraocular vein (Lee and Scheppens, “Aqueous-venous shunt and intraocular pressure,” Investigative Opthalmology (February 1966)). Other early glaucoma treatment implants led from the anterior chamber to a sub-conjunctival bleb (e.g., U.S. Pat. No. 4,968,296 and U.S. Pat. No. 5,180,362). Still others were shunts leading from the anterior chamber to a point just inside Schlemm's canal (Spiegel et al., “Schlemm's canal implant: a new method to lower intraocular pressure in patients with POAG?” Ophthalmic Surgery and Lasers (June 1999); U.S. Pat. No. 6,450,984; U.S. Pat. No. 6,450,984).
SUMMARY OF THE INVENTION
• One aspect of the invention provides an ocular implant having a first spine; a second spine; a first strut extending in an axial direction Z between the first spine and the second spine; a second strut extending in an axial direction Z between the first spine and the second spine; wherein an angular dimension θ of a first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.
• Yet another aspect of the invention provides an ocular implant having a first spine section; a second spine section; and a first frame extending between the first spine section and the second spine section, the frame having a diameter of between 0.005 inches and 0.04 inches, the ocular implant being adapted to be disposed within a canal of Schlemm in a human eye.
• In some embodiments, the first spine section, the second spine section, and the first frame form portions of a single tubular wall. Each spine section may optionally have only a single spine. In some embodiments, each spine section has an arcuate shape in lateral cross section. In some embodiments, the first spine has a first circumferential extent and the first frame has a second circumferential extent, wherein the second circumferential extent is greater than the first circumferential extent.
• In some embodiments, the first frame has a first strut and a second strut and may have only two struts. Each strut may optionally have an arcuate shape in lateral cross section.
• In embodiments in which the first strut has a first edge (partially defining, e.g., a first opening in the ocular implant), an angular dimension θ of the first edge may undulate as the strut extends in an axial direction Z between the first spine and the second spine. An angular dimension θ of the first edge may also first increase, then decrease, as the strut extends in an axial direction Z between the first spine and the second spine. Also, a radius r of the first edge may remain substantially constant as the strut extends in axial dimension Z between the first spine and the second spine.
• In some embodiments, the first strut has a thickness that is substantially constant in a radial direction. In some embodiments, the first strut has a width extending in an arc along a circumferential direction. In some embodiments, the first strut has a length extending in an axial direction that is generally parallel to a longitudinal axis of the ocular implant.
• The first spine section and the second spine section may be axially aligned with one another. A shape of the second strut may also be a mirror image of a shape of the first strut.
• Some embodiments of the ocular implant have a second frame extending between the second spine and a third spine. Some embodiments of the ocular implant have a first opening extending between the first edge of the first strut and the first edge of the second strut. In some embodiments, a second edge of the first strut and a second edge of the second strut defining a second opening. In some embodiments, the first strut, the second strut, the first spine section, and the second spine section all define a cylindrical volume.
• Some embodiments of the ocular implant have a therapeutic agent (e.g., an anti-glaucoma drug such as a prostaglandin analog like latanprost) deposited on the frame and spine sections.
• Still another aspect of the invention provides an ocular implant having a first spine; a second spine; a first frame comprising a first strut and a second strut; each strut extending in an axial direction Z between the first spine and the second spine; a first opening of the ocular implant extending between a first edge of the first strut and a first edge of the second strut; a second edge of the first strut and a second edge of the second strut defining a second opening; wherein an angular dimension θ of the first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is an isometric view showing a body that may be used to form an ocular implant in accordance with one exemplary embodiment of the invention. The body comprises a first spine, a second spine, and a first frame disposed between the first spine and the second spine. The first frame comprises a first strut and a second strut.
• FIG. 2 is an isometric view of the body shown in the previous figure. In the embodiment ofFIG. 2, the body is shaped to form an ocular implant having an outer surface defining a generally cylindrical volume. An inner surface of the body defines an elongate channel. The ocular implant may be inserted into Schlemm's canal of a human eye to facilitate the flow of aqueous humor out of the anterior chamber.
• FIG. 3A is a plan view showing a portion of the ocular implant shown in the previous figure. The ocular implant includes a first frame comprising a first strut and a second strut. In the exemplary embodiment ofFIG. 3A, each strut undulates in a circumferential direction while, at the same time, extending in the axial direction Z between a first spine and a second spine.
• FIG. 3B is a lateral cross-sectional view of the ocular implant shown in the previous figure. Section line B-B intersects the first strut and second strut of the ocular implant at the point where the circumferential undulation of these struts is at it's maximum. These struts form a frame having circumferential extent that is illustrated using dimension lines inFIG. 3B.
• FIG. 3C is a lateral cross-sectional view of the ocular implant ofFIG. 3A taken along section line C-C. Section line C-C intersects a spine of the ocular implant at the point where the width of the spine is at a minimum. A circumferential extent of the spine illustrated using dimension lines inFIG. 3C. With reference toFIG. 3C andFIG. 3B, it will be appreciated that the circumferential extent of frame is greater than the circumferential extent of the spine.
• FIG. 4 is an isometric view showing a portion of the ocular implant shown in the previous figure. With reference toFIG. 4, it will be appreciated that the outer surfaces of the first spine, the second spine, the first strut, and the second strut define a generally cylindrical volume V. The shape of the ocular implant may be described using the cylindrical coordinates shown inFIG. 4.
• FIG. 5 is an enlarged plan view showing a portion of the ocular implant shown in the previous figure. InFIG. 5, a number of section lines are shown crossing the first strut and the second strut of the ocular implant. In the embodiment ofFIG. 5, each strut undulates in a circumferential direction while, at the same time, extending in axial direction Z between the first spine and the second spine. The circumferential undulation of the first strut is illustrated inFIG. 6 using lateral cross-sectional drawings labeled with cylindrical coordinates.
• FIG. 6A through 6E are lateral cross-sectional views of the ocular implant shown in the previous figure. These cross-sectional views correspond to the section lines shown in the previous figure. With reference to these cross-sectional views, it will be appreciated that the angular dimension θ associated with a first edge of the first strut undulates as the first strut extends in an axial direction Z between the first spine and the second spine. In the embodiment ofFIG. 6, the radius r of the outer surface of the first strut remains substantially constant as the first strut extends in the axial direction Z between the first spine and the second spine.
• FIG. 7 shows a plurality of cylindrical coordinate values corresponding with the cross-sectional views shown in the previous figure.
• FIG. 8 is an isometric view of an ocular implant in accordance with an additional exemplary embodiment of the invention.
• FIG. 9 is a plan view of the ocular implant shown in the previous figure. In the embodiment ofFIG. 9, the ocular implant has an at rest shape that is generally curved.
• FIG. 10 shows the ocular implant of the previous figure in place within a human eye.
• FIG. 11 is an enlarged plan view showing a portion of the eye shown in the previous figure.
DETAILED DESCRIPTION
• The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings, which are not necessarily to scale, depict exemplary embodiments and are not intended to limit the scope of the invention. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements. All other elements employ that which is known to those of skill in the field of the invention. Those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized.
• FIG. 1 is an isometric view showing abody100 that may be used to form an ocular implant in accordance with one exemplary embodiment of the invention.Body100 comprises afirst spine102, asecond spine104, and afirst frame106 disposed betweenfirst spine102 andsecond spine104. In the embodiment ofFIG. 1,first frame106 comprises afirst strut120 and asecond strut122. With reference toFIG. 1, it will be appreciated that each strut extends betweenfirst spine102 andsecond spine104.
• First strut120 offirst frame106 comprises afirst edge124A and asecond edge126A. With reference toFIG. 1, it will be appreciated thatsecond strut122 has a shape that is a mirror image of the shape offirst strut120.Second strut122 comprises afirst edge124B and asecond edge126B.Second edge126B ofsecond strut122 andsecond edge126A offirst strut120 define asecond opening130.Second opening130 generally dividesfirst frame106 intofirst strut120 andsecond strut122.
• With continuing reference toFIG. 1, it will be appreciated thatbody100 comprises a plurality of spines and a plurality of frames. In the embodiment ofFIG. 1, these spines and frames are arranged in an ABAB pattern. Each spine has a firstlateral extent132 and each frame has a secondlateral extent134. With reference toFIG. 1, it will be appreciated that secondlateral extent134 is greater than firstlateral extent132.
• FIG. 2 is an isometric view ofbody100 shown in the previous figure. In the embodiment ofFIG. 2,body100 is shaped to form anocular implant136 having anouter surface138 defining a generally cylindrical volume. Aninner surface140 ofbody100 defines anelongate channel142.Ocular implant136 may be inserted into Schlemm's canal of a human eye to facilitate the flow of aqueous humor out of the anterior chamber. This flow may include axial flow along Schlemm's canal, flow from the anterior chamber into Schlemm's canal, and flow leaving Schlemm's canal via outlets communicating with Schlemm's canal. When in place within the eye,ocular implant136 will support trabecular mesh tissue and Schlemm's canal tissue and will provide for improved communication between the anterior chamber and Schlemm's canal (via the trabecular meshwork) and between pockets or compartments along Schlemm's canal.
• Elongate channel142 ofocular implant136 fluidly communicates with afirst opening128 as well asinlet portion101. Various fabrication techniques may be used to fabricateocular implant136. For example,ocular implant136 can be fabricated by providing a generally flat sheet of material and laser cutting the sheet of material to formbody100 shown inFIG. 1. Thebody100 may then be formed into a generally tubular shape as shown inFIG. 2. Any adjoining edges (such as edges103) may be, optionally, welded. By way of a second example,ocular implant136 may be fabricated by providing a tube and laser cutting openings in the tube to form the shape shown inFIG. 2.
• As shown inFIG. 2,ocular implant136 comprises afirst spine102 and asecond spine104. Afirst frame106 ofocular implant136 is disposed betweenfirst spine102 andsecond spine104. In the embodiment ofFIG. 2,first frame106 comprises afirst strut120 that extends betweenfirst spine102 andsecond spine104.First frame106 also comprises asecond strut122.Second strut122 also extends betweenfirst spine102 andsecond spine104.
• First strut120 offirst frame106 comprises afirst edge124A and asecond edge126A.Second strut122 has a shape that is a mirror image of the shape offirst strut120. InFIG. 2,first opening128 ofocular implant136 can be seen extending betweenfirst edge124A offirst strut120 and afirst edge124B ofsecond strut122. Asecond edge126B ofsecond strut122 andsecond edge126A offirst strut120 define asecond opening130.Second opening130 and additional openings (e.g., first opening128) defined byocular implant136 allow aqueous humor to flow laterally across and/or laterally throughocular implant136.
• Ocular implant136 can be fabricated from various biocompatible materials possessing the necessary structural and mechanical attributes. Both metallic and non-metallic materials may be suitable. Examples of metallic materials include stainless steel, tantalum, gold, titanium, and nickel-titanium alloys known in the art as Nitinol. Nitinol is commercially available from Memry Technologies (Brookfield, Conn.), TiNi Alloy Company (San Leandro, Calif.), and Shape Memory Applications (Sunnyvale, Calif.).
• Ocular implant136 may include one or more therapeutic agents. One or more therapeutic agents may, for example, be incorporated into a polymeric coating that is deposited onto the outer surfaces of the struts and spines of the ocular implant. The therapeutic agent may comprise, for example, an anti-glaucoma drug. Examples of anti-glaucoma drugs include prostaglandin analogs. Examples of prostaglandin analogs include latanprost.
• FIG. 3A is a plan view showing a portion ofocular implant136 shown in the previous figure.Body100 ofocular implant136 comprises afirst spine102, asecond spine104, and afirst frame106 disposed betweenfirst spine102 andsecond spine104. In the embodiment ofFIG. 3A,first frame106 comprises afirst strut120 and asecond strut122. As shown, each strut undulates in a circumferential direction while, at the same time, extending in the axial direction Z betweenfirst spine102 andsecond spine104.
• FIG. 3B is a lateral cross-sectional view ofocular implant136 taken along section line B-B. Section line B-B intersectsfirst strut120 andsecond strut122 at the point where the circumferential undulation of these struts is at its maximum.First strut120 andsecond strut122 formfirst frame106.First frame106 has a firstcircumferential extent144 in the embodiment ofFIG. 3B.
• FIG. 3C is a lateral cross-sectional view ofocular implant136 taken along section line C-C. Section line C-C intersectsfirst spine102 at the point where the width offirst spine102 is at a minimum. At this point,first spine102 has a secondcircumferential extent146. Secondcircumferential extent146 offirst spine102 is illustrated using dimension lines inFIG. 3C. With reference toFIG. 3C andFIG. 3B, it will be appreciated that firstcircumferential extent144 offirst frame106 is greater than secondcircumferential extent146 offirst spine102.
• FIG. 4 is an isometric view showing a portion ofocular implant136 shown in the previous figure. With reference toFIG. 4, it will be appreciated that the outer surfaces offirst spine102,second spine104,first strut120, andsecond strut122 define a portion of a generally cylindrical volume V. The shape ofocular implant136 may be described using the cylindrical coordinates shown inFIG. 4. These cylindrical coordinates include a radius r, an angle θ and an axial dimension Z. Cylindrical coordinates may be conceptualized as an extension of two dimensional polar coordinates to include a longitudinal or axial dimension Z. The two dimensions of a typical polar coordinate system are radius r and angle θ. In the embodiment ofFIG. 4, dimension Z extends along alongitudinal axis148 of cylindrical volume V.
• As shown inFIG. 4,first strut120 extends in axial direction Z betweenfirst spine102 andsecond spine104.Second strut122 also extends betweenfirst spine102 andsecond spine104. In the embodiment ofFIG. 4, the radius r of the outer surface of each strut remains substantially constant. The angular dimension θ of afirst edge124A of first strut varies asfirst strut120 extends in the axial direction Z betweenfirst spine102 andsecond spine104. Similarly, the angular dimension θ of asecond edge126A of second strut varies assecond strut122 extends in the axial direction Z betweenfirst spine102 andsecond spine104.
• FIG. 5 is an enlarged plan view showing a portion ofocular implant136 shown in the previous figure. InFIG. 5, a number of section lines are shown crossingfirst strut120 andsecond strut122 ofocular implant136. In the embodiment ofFIG. 5, each strut undulates in a circumferential direction while, at the same time, extending in axial direction Z betweenfirst spine102 andsecond spine104. The circumferential undulation offirst strut120 is illustrated in the next figure using lateral cross-sectional drawings labeled with cylindrical coordinates.
• FIG. 6A through 6E are lateral cross-sectional views ofocular implant136 shown in the previous figure. These cross-sectional views correspond to the section lines shown in the previous figure. With reference to these cross-sectional views, it will be appreciated that the angular dimension θ associated withfirst edge124A offirst strut120 undulates asfirst strut120 extends in an axial direction Z between the first spine and the second spine. In the embodiment ofFIG. 6, the radius r of the outer surface offirst strut120 remains substantially constant asfirst strut120 extends in axial direction Z between the first spine and the second spine.
• FIG. 7 shows a plurality of cylindrical coordinate values corresponding with the cross-sectional views shown in the previous figure. With reference to the numerical values shown inFIG. 7, it will be appreciated that the numerical value of angular dimension θ of first edge124 first increases, then decreases, asfirst strut120 extends in an axial direction Z between the first spine and the second spine. The numerical value r remains constant asfirst strut120 extends in axial direction Z between the first spine and the second spine.
• FIG. 8 is an isometric view of anocular implant236 in accordance with an additional exemplary embodiment of the invention. As shown inFIG. 8,ocular implant236 comprises afirst spine202 and asecond spine204. Afirst frame206 ofocular implant236 is disposed betweenfirst spine202 andsecond spine204. In the embodiment ofFIG. 8,first frame206 comprises afirst strut220 that extends betweenfirst spine202 andsecond spine204.First frame206 also comprises asecond strut222. With reference toFIG. 8, it will be appreciated thatsecond strut222 also extends betweenfirst spine202 andsecond spine204.
• Ocular implant236 ofFIG. 8 defines achannel242 that opens into afirst opening228. InFIG. 8,first opening228 ofocular implant236 can be seen extending betweenfirst strut220 andsecond strut222.First strut220 andsecond strut222 also define asecond opening230.First opening228,second opening230, and the additional openings shown inFIG. 8, allow aqueous humor to flow laterally across and/or laterally throughocular implant236.
• In the embodiment ofFIG. 8, aninlet portion250 is formed near a proximal end ofocular implant236.Inlet portion250 may extend through the trabecular meshwork into the anterior chamber of the eye when a portion of the ocular implant lies in Schlemm's canal.
• In the embodiment ofFIG. 8, ablunt tip252 is disposed at a distal end ofocular implant236. In some useful embodiments ofocular implant236,blunt tip252 has a generally rounded shape. In the embodiment shown inFIG. 8,blunt tip252 has a generally hemispherical shape. The generally rounded shape ofblunt tip252 may increase the likelihood that body200 will track Schlemm's canal asocular implant236 is advanced into the canal during an implant procedure.
• InFIG. 8,ocular implant236 is pictured assuming a generally straight shape. Embodiments ofocular implant236 are possible which have a generally curved resting shape.Ocular implant236 may be fabricated, for example, by laser cutting a tube to create the shape shown inFIG. 8. When this is the case, it may be desirable to rotate a straight tubular workpiece during the laser cutting process. After the laser cutting process, the ocular implant can be heat-set so that the ocular implant is biased to assume a selected shape (e.g., a generally curved shape).
• FIG. 9 is a plan view ofocular implant236 shown in the previous figure. In the embodiment ofFIG. 9,ocular implant236 has an at rest shape that is generally curved. This at rest shape can be established, for example, using a heat-setting process. The ocular implant shape shown inFIG. 9 includes a distal radius RA, a proximal radius RC, and an intermediate radius RB. In the embodiment ofFIG. 9, distal radius RA is larger than both intermediate radius RB and proximal radius RC. Also in the embodiment ofFIG. 9, intermediate radius RB is larger than proximal radius RC and smaller than distal radius RA. In one useful embodiment, distal radius RA is about 0.310 inches, intermediate radius RB is about 0.215 inches and proximal radius RC is about 0.105 inches.
• In the embodiment ofFIG. 9, a distal portion of the ocular implant follows distal radius RA along an arc extending across an angle AA. A proximal portion of the ocular implant follows proximal radius RC along an arc extending across an angle AC. An intermediate portion of the ocular implant is disposed between the proximal portion and the distal portion. The intermediate portion follows radius RB and extends across an angle AB. In one useful embodiment, angle AA is about 55 degrees, angle AB is about 79 degrees and angle AC is about 60 degrees.
• Ocular implant236 may be used in conjunction with a method of treating a patient. Some such methods may include the step of inserting a core member into a lumen defined byocular implant236. The core member may comprise, for example, a wire or tube. The distal end of the ocular implant may be inserted into Schlemm's canal. The ocular implant and the core member may then be advanced into Schlemm's canal until the ocular implant has reached a desired position. The core member may then be withdrawn from the ocular implant.
• FIG. 10 showsocular implant236 of the previous figure in place within a human eye. The eye ofFIG. 10 includes an anterior chamber that is covered by a cornea. The iris of the eye is visible through the cornea and the anterior chamber. The anterior chamber is filled with aqueous humor which helps maintain the generally hemispherical shape of the cornea.
• Whenever a person views an object, he or she is viewing that object through the cornea, the aqueous humor, and the lens of the eye. In order to be transparent, the cornea and the lens can include no blood vessels. Accordingly, no blood flows through the cornea and the lens to provide nutrition to these tissues and to remove wastes from these tissues. Instead, these functions are performed by the aqueous humor. A continuous flow of aqueous humor through the eye provides nutrition to portions of the eye (e.g., the cornea and the lens) that have no blood vessels. This flow of aqueous humor also removes waste from these tissues.
• Aqueous humor is produced by an organ known as the ciliary body. The ciliary body includes epithelial cells that continuously secrete aqueous humor. In a healthy eye, a stream of aqueous humor flows out of the eye as new aqueous humor is secreted by the epithelial cells of the ciliary body. This excess aqueous humor enters the blood stream and is carried away by venous blood leaving the eye.
• The structures that drain aqueous humor from the anterior chamber include Schlemm's canal and a large number of veins that communicate with Schlemm's canal via a plurality of outlets. InFIG. 10, Schlemm'scanal20 can be seen encircling the iris of the eye.Ocular implant236 may be inserted into Schlemm'scanal20 to facilitate the flow of aqueous humor out of the anterior chamber. This flow may include axial flow along Schlemm's canal, flow from the anterior chamber into Schlemm's canal, and flow leaving Schlemm's canal via outlets communicating with Schlemm's canal. When in place within the eye,ocular implant236 will support trabecular mesh tissue and Schlemm's canal tissue and will provide for improved communication between the anterior chamber and Schlemm's canal (via the trabecular meshwork) and between pockets or compartments along Schlemm's canal.
• FIG. 11 is an enlarged plan view showing a portion of the eye shown in the previous figure. With reference toFIG. 11, it will be appreciated thatocular implant236 extends through Schlemm'scanal20 across an angle G. Various implant sizes are possible, and different implant sizes may span a different angle G when placed in Schlemm's canal. Examples of angular spans that may be suitable in some applications include 60°, 90°, 150° and 180°.
• InFIG. 11, aninlet portion250 ofocular implant236 is shown extending throughtrabecular mesh22. Aqueous humor may exitanterior chamber24 and enter Schlemm'scanal20 by flowing throughinlet portion250 ofocular implant236. Aqueous humor may also exitanterior chamber24 and enter Schlemm'scanal20 by flowing through thetrabecular mesh22 of the eye. With reference toFIG. 11, it will be appreciated that the spines ofocular implant236support trabecular mesh22.
• Aqueous humor exits Schlemm'scanal20 by flowing through a number of outlets. After leaving Schlemm'scanal20, aqueous humor travels through a network passages and veins and is absorbed into the blood stream. Schlemm's canal typically has a non-circular cross-sectional shape whose diameter can vary along the canal's length and according to the angle at which the diameter is measured. In addition, there may be multiple partial pockets or partial compartments (not shown in these figures) formed along the length of Schlemm's canal. The shape and diameter of portions of Schlemm's canal and the existence and relative location of partial pockets or compartments may limit or prevent fluid flow from one point of Schlemm's canal to another. Hence, each outlet from Schlemm's canal may drain only a portion of Schlemm's canal. This condition may be improved by placingocular implant236 in Schlemm's canal.Ocular implant236 shown inFIG. 11 includes a plurality of struts, spines and openings. When in place within the eye,ocular implant236 will support trabecular mesh tissue and Schlemm's canal tissue and will provide for improved communication between the anterior chamber and Schlemm's canal and between pockets or compartments along Schlemm's canal.
• InFIG. 11,first opening228 ofocular implant236 is shown facing radially outward in Schlemm'scanal20. Aqueous humor can exit Schlemm'scanal20 by flowing through outlets that radiate away from and communicate with Schlemm'scanal20. After flowing through these outlets, this excess aqueous humor can enter the venous bloodstream be carried out of the eye by venous blood flow. The diameter ofocular implant236 can range from 0.005 inches to 0.04 inches, preferably from 0.005 inches to 0.02 inches, in order to lie within and support Schlemm's canal.
• While exemplary embodiments of the present invention have been shown and described, modifications may be made, and it is therefore intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.

Claims (28)

1. An ocular implant, comprising:

a first spine;

a second spine;

a first strut extending in an axial direction Z between the first spine and the second spine;

a second strut extending in an axial direction Z between the first spine and the second spine;

wherein an angular dimension θ of a first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and

wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.

2. An ocular implant, comprising:

a first spine section;

a second spine section;

a first frame extending between the first spine section and the second spine section, the frame having a diameter of between 0.005 inches and 0.04 inches;

the ocular implant being adapted to be disposed within a canal of Schlemm in a human subject's eye.

3. The ocular implant ofclaim 2, wherein the first spine section, the second spine section, and the first frame comprise portions of a single tubular wall.

4. The ocular implant ofclaim 2, wherein each spine section comprises only a single spine.

5. The ocular implant ofclaim 2, wherein each spine section has an arcuate shape in lateral cross section.

6. The ocular implant ofclaim 2, wherein:

the first spine has a first circumferential extent; and

the first frame has a second circumferential extent;

wherein the second circumferential extent is greater than the first circumferential extent.

7. The ocular implant ofclaim 2, wherein the first frame comprises a first strut and a second strut.

8. The ocular implant ofclaim 7, wherein the first frame comprises only two struts.

9. The ocular implant ofclaim 7, wherein each strut has an arcuate shape in lateral cross section.

10. The ocular implant ofclaim 7, wherein the first strut comprises a first edge.

11. The ocular implant ofclaim 10, wherein an angular dimension θ of the first edge undulates as the strut extends in an axial direction Z between the first spine and the second spine.

12. The ocular implant ofclaim 10, wherein an angular dimension θ of the first edge first increases, then decreases, as the strut extends in an axial direction Z between the first spine and the second spine.

13. The ocular implant ofclaim 10, wherein a radius r of the first edge remains substantially constant as the strut extends in axial dimension Z between the first spine and the second spine.

14. The ocular implant ofclaim 10, wherein the first edge partially defines a first opening in the ocular implant.

15. The ocular implant ofclaim 7, wherein the first strut has a thickness that is substantially constant in a radial direction.

16. The ocular implant ofclaim 7, wherein the first strut has a width extending in an arc along a circumferential direction.

17. The ocular implant ofclaim 7, wherein the first strut has a length extending in an axial direction that is generally parallel to a longitudinal axis of the ocular implant.

18. The ocular implant ofclaim 7, wherein the first spine section and the second spine section are axially aligned with one another.

19. The ocular implant ofclaim 7, wherein a shape of the second strut is a mirror image of a shape of the first strut.

20. The ocular implant ofclaim 7, further comprising a second frame extending between the second spine and a third spine.

21. The ocular implant ofclaim 7, wherein a second edge of the first strut and a second edge of the second strut defining a second opening.

22. The ocular implant ofclaim 7, wherein the first strut, the second strut, the first spine section, and the second spine section all define a cylindrical volume.

23. The ocular implant ofclaim 7, further comprising a first opening extending between the first edge of the first strut and the first edge of the second strut.

24. The implant ofclaim 2 further comprising a therapeutic agent deposited on the frame and spine sections.

25. The implant ofclaim 24 wherein the therapeutic agent comprises an anti-glaucoma drug.

26. The implant ofclaim 25 wherein the anti-glaucoma drug comprises a prostaglandin analog.

27. The implant ofclaim 26 wherein the prostaglandin analog comprises latanprost.

28. An ocular implant, comprising:

a first spine;

a second spine;

a first frame comprising a first strut and a second strut;

each strut extending in an axial direction Z between the first spine and the second spine;

a first opening of the ocular implant extending between a first edge of the first strut and a first edge of the second strut;

a second edge of the first strut and a second edge of the second strut defining a second opening;

wherein an angular dimension θ of the first edge of each strut undulates as the strut extends in the axial direction Z between the first spine and the second spine; and

wherein a radius r of an outer surface of each strut remains substantially constant as the strut extends the axial direction Z between the first spine and the second spine.

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