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Abstract #5602 Published in IGR 2-1
Swelling and loss of photoreceptors in chronic human and experimental glaucomas
Nork TM; Ver Hoeve JN; Poulsen GL; Nickells RW; Davis MD; Weber AJ; Vaegan; Sarks SH; Lemley HL; Millecchia LLArchives of Ophthalmology 2000; 118:235-245
OBJECTIVE: To determine whether outer retinal changes occur in chronic, presumed primary open-angle glaucoma (POAG). METHODS: The outer retinas from 128 human eyes with a diagnosis of chronic glaucoma (presumably POAG in most cases) and 90 control eyes were examined histologically by three masked observers for photoreceptor swelling and loss. Retinas from nine rhesus monkeys with glaucoma induced experimentally by laser trabecular destruction were compared with seven fellow (control) eyes. The mean pressure elevations in the eyes with laser trabecular destruction ranged from 26.6-53.6 mmHg with durations varying from seven to 33 weeks. RESULTS: Swelling of the red- and green-sensitive cones was observed in a statistically significantly greater proportion of human eyes with presumed POAG compared with the control eyes. Patchy loss of red/green cones and rods was also found in some of the glaucomatous retinas. In a subset of the human eyes with end-stage disease, cone swelling was a variable finding. Although no photoreceptor loss was found in the nine monkey eyes with experimental glaucoma, eight had swelling of their red/green cones that was remarkably similar to that seen in the human eyes. Swelling was not present in any of the control monkey eyes. CONCLUSION: The photoreceptors are affected by chronically elevated intraocular pressure. CLINICAL RELEVANCE: These findings may explain some of the abnormalities of color vision and the electrophysiological effects that have been observed in patients with POAG.
Dr. T.M. Nork, Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison, WI 53792-3220, USA tmnork@facstaff.wisc.edu
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
3.2 Electron microscopy (Part of: 3 Laboratory methods)
