When they reach the internal surface of the retina they radiate from their point of entrance over this surface grouped in bundles, and in many places arranged inplexuses.
Most of the fibers are centripetal, and are the direct continuations of the axis-cylinder processes of the cells of theganglionic layer, but a few of them arecentrifugal and ramify in theinner plexiform andinner nuclear layers, where they end in enlarged extremities.
Patients withretinitis pigmentosa have abnormal thinning of the RNFL which correlates with the severity of the disease.[2] However the thickness of the RNFL also decreases with age and not visual acuity.[3] The sparing of this layer is important in the treatment of the disease as it is the basis for connecting retinal prostheses to the optic nerve, or implanting stem cells that could regenerate the lost photoreceptors.
RNFL asymmetry is the difference between the RNFL of the left and right eyes. In healthy patients, one study (2008, n=109) found asymmetry to be typically between 0-8μm, but occasionally higher, with average asymmetry of c.3μm at age 25 rising to 5μm at age 60.[4] A 2011 study (n=284) concluded that RNFL asymmetry exceeding 9μm may be considered statistically significant and may be indicative of early glaucomatous damage.[5] A 2023 study of 4034 children found mean RNFL of 106μm with SD of 9.4μm.[6]
RNFL asymmetry has been proposed as a strong indicator ofoptic neuritis,[7][8] with one small study proposing that asymmetry of 5–6μm was "a robust structural threshold for identifying the presence of a unilateral optic nerve lesion in MS."[9] Optic neuritis is often associated withmultiple sclerosis, and RNFL data may indicate the pace of future development of the MS.[10][11]
RNFL asymmetry may be produced byglaucoma.[12][13][14][15] Glaucoma is a lead cause of irreversible blindness. Resesrch in RNFL and optic nerve head (ONH) abnormalities may enable early detection and diagnosis of glaucoma.[2]
Some processes can excite RNFLapoptosis. Harmful situations which can damage RNFL include high intraocular pressure, high fluctuation on phase of intraocular pressure, inflammation, vascular disease and any kind of hypoxia. Gede Pardianto (2009) reported 6 cases of RNFL thickness change after the procedures ofphacoemulsification.[20] Sudden intraocular fluctuation in any kind of intraocular surgeries maybe harmful to RNFL in accordance with mechanical stress on sudden compression and also ischemic effect of micro emboly as the result of the sudden decompression that may generate micro bubble that can clog micro vessels.[21]
^Oishi A, Otani A, Sasahara M, Kurimoto M, Nakamura H, Kojima H, et al. (March 2009). "Retinal nerve fiber layer thickness in patients with retinitis pigmentosa".Eye.23 (3):561–6.doi:10.1038/eye.2008.63.PMID18344951.
^Berenguer-Vidal R, Verdú-Monedero R, Morales-Sánchez J, Sellés-Navarro I, Kovalyk O (2022). "Analysis of the Asymmetry in RNFL Thickness Using Spectralis OCT Measurements in Healthy and Glaucoma Patients".Artificial Intelligence in Neuroscience: Affective Analysis and Health Applications. Lecture Notes in Computer Science. Vol. 13258. pp. 507–515.doi:10.1007/978-3-031-06242-1_50.ISBN978-3-031-06241-4.
This article incorporates text in thepublic domain frompage 1015 of the 20th edition ofGray's Anatomy(1918)
