Xiang-Run Huang1,2, Robert W Knighton1, Ye Z Spector1,2, William J Feuer1. 1. a Bascom Palmer Eye Institute , Miller School of Medicine University of Miami , Miami , FL , USA. 2. b Department of Biomedical Engineering , College of Engineering University of Miami , Coral Gables , FL , USA.
Abstract
PURPOSE: Glaucoma damages the retinal nerve fiber layer (RNFL). Both RNFL thickness and retardance can be used to assess the damage, but birefringence, the ratio of retardance to thickness, is a property of the tissue itself. This study investigated the relationship between axonal cytoskeleton and RNFL birefringence in retinas with hypertensive damage. MATERIALS AND METHODS: High intraocular pressure (IOP) was induced unilaterally in rat eyes. RNFL retardance in isolated retinas was measured. Cytostructural organization and bundle thickness were evaluated by confocal imaging of immunohistochemical staining of the cytoskeletal components: microtubules (MTs), F-actin, and neurofilaments. Bundles with different appearances of MT stain were studied, and their birefringence was calculated at different radii from the optic nerve head (ONH) center. RESULTS: Forty bundles in eight normal retinas and 37 bundles in 10 treated retinas were examined. In normal retinas, the stain of axonal cytoskeleton was approximately uniform within bundles, and RNFL birefringence did not change along bundles. In treated retinas, elevation of IOP caused non-uniform alteration of axonal cytoskeleton across the retina, and distortion of axonal MTs was associated with decreased birefringence. The study further demonstrated that change of RNFL birefringence profiles along bundles can imply altered axonal cytoskeleton, suggesting that ultrastructural change of the RNFL can be inferred from clinical measurements of RNFL birefringence. The study also demonstrated that measuring RNFL birefringence profiles along bundles, instead of at a single location, may provide a more sensitive way to detect axonal ultrastructural change. CONCLUSIONS: Measurement of RNFL birefringence along bundles can provide estimation of cytoskeleton alteration and sensitive detection of glaucomatous damage.
PURPOSE:Glaucoma damages the retinal nerve fiber layer (RNFL). Both RNFL thickness and retardance can be used to assess the damage, but birefringence, the ratio of retardance to thickness, is a property of the tissue itself. This study investigated the relationship between axonal cytoskeleton and RNFL birefringence in retinas with hypertensive damage. MATERIALS AND METHODS: High intraocular pressure (IOP) was induced unilaterally in rat eyes. RNFL retardance in isolated retinas was measured. Cytostructural organization and bundle thickness were evaluated by confocal imaging of immunohistochemical staining of the cytoskeletal components: microtubules (MTs), F-actin, and neurofilaments. Bundles with different appearances of MT stain were studied, and their birefringence was calculated at different radii from the optic nerve head (ONH) center. RESULTS: Forty bundles in eight normal retinas and 37 bundles in 10 treated retinas were examined. In normal retinas, the stain of axonal cytoskeleton was approximately uniform within bundles, and RNFL birefringence did not change along bundles. In treated retinas, elevation of IOP caused non-uniform alteration of axonal cytoskeleton across the retina, and distortion of axonal MTs was associated with decreased birefringence. The study further demonstrated that change of RNFL birefringence profiles along bundles can imply altered axonal cytoskeleton, suggesting that ultrastructural change of the RNFL can be inferred from clinical measurements of RNFL birefringence. The study also demonstrated that measuring RNFL birefringence profiles along bundles, instead of at a single location, may provide a more sensitive way to detect axonal ultrastructural change. CONCLUSIONS: Measurement of RNFL birefringence along bundles can provide estimation of cytoskeleton alteration and sensitive detection of glaucomatous damage.
Authors: T W Mittag; J Danias; G Pohorenec; H M Yuan; E Burakgazi; R Chalmers-Redman; S M Podos; W G Tatton Journal: Invest Ophthalmol Vis Sci Date: 2000-10 Impact factor: 4.799
Authors: Sylvia Desissaire; Andreas Pollreisz; Aleksandra Sedova; Dorottya Hajdu; Felix Datlinger; Stefan Steiner; Clemens Vass; Florian Schwarzhans; Georg Fischer; Michael Pircher; Ursula Schmidt-Erfurth; Christoph K Hitzenberger Journal: Biomed Opt Express Date: 2020-09-10 Impact factor: 3.732
Authors: David A Miller; Marta Grannonico; Mingna Liu; Roman V Kuranov; Peter A Netland; Xiaorong Liu; Hao F Zhang Journal: Transl Vis Sci Technol Date: 2020-10-09 Impact factor: 3.283