Search results for "ganglion cells"
showing 10 items of 66 documents
Effect of multizone refractive multifocal contact lenses on the Cirrus HD OCT retinal measurements
2011
Background Simultaneous vision multifocal contact lenses are widely used to alleviate the symptoms of presbyopia. These contact lenses create simultaneous retinal images due to the incoming light distribution being divided into two or more focuses. Our aim was to evaluate whether the multizone refractive multifocal contact lenses affect the measurements of the retinal nerve fibre layer (RNFL) and macular thickness using optical coherence tomography (OCT). Methods In this cross-over study, 30 eyes of 30 subjects with a mean age of 50.42 ± 7.82 years were fitted with multizone refractive multifocal contact lenses. Using the RNFL Thickness Analysis mode of the Cirrus HD (Carl Zeiss, Meditec, D…
Autoreactive Antibodies and Loss of Retinal Ganglion Cells in Rats Induced by Immunization with Ocular Antigens
2011
PURPOSE In an experimental autoimmune animal model, retinal ganglion cell (RGC) loss was induced through immunization with glaucoma-related antigens. The target of this study was to investigate the pathomechanism behind this decline and the serum antibody reactivity against ocular and neuronal tissues after immunization with glaucoma- and non-glaucoma-associated antigens. METHODS Rats immunized with optic nerve antigen homogenate (ONA) or keratin (KER) were compared to control rats (CO). Intraocular pressure (IOP) was measured, and the fundi were examined regularly. Four weeks afterward, cells were counted in retinal flat mounts. Retina, optic nerve, and brain sections from healthy animals …
Analysis of Autoantibody Repertoires in Sera of Patients with Glaucoma
2003
PURPOSE Glaucoma is the second cause of blindness worldwide. It is usually considered a neurodegenerative disease. There is evidence that an autoimmune mechanism is involved in the development of glaucoma in some patients. The aim of this study was to analyze the IgG autoantibody repertoires in sera of glaucoma patients and healthy subjects. METHODS A total of 82 patients were divided into four groups: healthy volunteers without any ocular disorders (CO, n = 30), patients with primary open-angle glaucoma (POAG, n = 19), ocular hypertension (OHT, n = 16), and normal tension glaucoma (NTG, n = 17). All groups were matched for age and gender. The sera of these patients were tested against West…
Relationship between Psychophysical Measures of Retinal Ganglion Cell Density and In Vivo Measures of Cone Density in Glaucoma.
2017
Purpose Considerable between-individual variation in retinal ganglion cell (RGC) density exists in healthy individuals, making identification of change from normal to glaucoma difficult. In ascertaining local cone-to-RGC density ratios in healthy individuals, we wished to investigate the usefulness of objective cone density estimates as a surrogate of baseline RGC density in glaucoma patients, and thus a more efficient way of identifying early changes. Design Exploratory cohort study. Participants Twenty glaucoma patients (60% women) with a median age of 54 years and mean deviation (MD) in the visual field of –5 dB and 20 healthy controls (70% women) with a median age of 57 years and a mean…
Retrograde Maculopathy in Patients With Glaucoma
2017
PURPOSE Macular optical coherence tomography (OCT) analysis can be used for quantitative measures of optic nerve atrophy at a location far from the optic nerve head. This recently led to the finding of microcystic macular edema (MME), that is vacuolar inclusions in the macular inner nuclear layer, in some glaucoma patients. The involvement of individual retinal layers is yet unclear in glaucoma. In this study we systematically investigated glaucoma-induced changes in macular layers to evaluate whether glaucoma-associated damage extends beyond the macular ganglion cell layer. PATIENTS AND METHODS We included 218 consecutive patients and 282 eyes with confirmed primary open-angle glaucoma or …
Central retinal artery occlusion-A new, provisional treatment approach.
2019
The retinal ganglion cells infarcted in central retinal artery occlusion (CRAO) are the somata of the optic nerve axons, part of the central nervous system. Consequently, CRAO with inner retinal infarction is a small vessel stroke, usually with the devastating consequence of severe visual loss in the affected eye. At present, there is no generally accepted, evidence-based therapy of nonarteritic CRAO in contrast to ischemic cerebral stroke that has well-accepted treatment protocols. Widely divergent and controversial therapeutic options for CRAO reflect the desperation of treating physicians and disparate conflicting studies. We examine reasons why treatment of nonarteritic CRAO remains pro…
The role of glia, mitochondria, and the immune system in glaucoma.
2009
Author(s): Tezel, Gulgun; Fourth ARVO/Pfizer Ophthalmics Research Institute Conference Working Group
MeV ion beam lithography of biocompatible halogenated Parylenes using aperture masks
2015
Parylenes are poly(p-xylylene) polymers that are widely used as moisture barriers and in biomedicine because of their good biocompatibility. We have investigated MeV ion beam lithography using 16O+ ions for writing defined patterns in Parylene-C, which is evaluated as a coating material for the Cochlear Implant (CI) electrode array, a neuroprosthesis to treat some forms of deafness. Parylene-C and -F on silicon and glass substrates as well as 50 μm thick PTFE were irradiated to different fluences (1×1013-1×10161×1013-1×1016 1 MeV 16O+ ions cm−2) through aperture masks under high vacuum and a low pressure (<10−3 mbar) oxygen atmosphere. Biocompatibility of the irradiated and unirradiated …
Intravitreal delivery of AAV-NDI1 provides functional benefit in a murine model of Leber hereditary optic neuropathy.
2012
Leber hereditary optic neuropathy (LHON) is a mitochondrially inherited form of visual dysfunction caused by mutations in several genes encoding subunits of the mitochondrial respiratory NADH-ubiquinone oxidoreductase complex (complex I). Development of gene therapies for LHON has been impeded by genetic heterogeneity and the need to deliver therapies to the mitochondria of retinal ganglion cells (RGCs), the cells primarily affected in LHON. The therapy under development entails intraocular injection of a nuclear yeast gene NADH-quinone oxidoreductase (NDI1) that encodes a single subunit complex I equivalent and as such is mutation independent. NDI1 is imported into mitochondria due to an e…
Effects of Cyclooxygenase Inhibitors on Apoptotic Neuroretinal Cells
2008
Glaucoma is characterized by a loss of retinal ganglion cells (RGC) which is associated with a decrease of visual function. Neuroprotective agents as a new therapeutic strategy could prevent the remaining neurons from apoptotic cell death. Previous studies have shown the involvement of the Cyclooxygenase (COX)-2 signalling in the apoptotic death of neurons. Herein we investigated the neuroprotective effect of COX-1/COX-2- and selective COX-2- inhibitors on apoptotic. R28, a neuroretinal cell line and determined the PGE2 levels by ELISA. Furthermore we investigated differences in protein expression in the cells after exposure to elevated pressure compared to untreated cells by ProteinChip a…