Morphometric analysis of the macula in eyes with disciform age-related macular degeneration

Purpose: To evaluate the extent of neural cell death in eyes with disciform age-related macular degeneration. Methods: Six eyes with disciform degeneration at various stages and five age-matched control eyes were selected for morphometric analysis using digitized light microscopic images. Disciform scars were classified as subneurosensory retinal, subretinal pigment epithelial, or combined lesions. The nuclei of the ganglion cell, inner nuclear, and outer nuclear layers were counted in contiguous 100-mum segments spanning a distance from 1,500 mum nasal to 1,500 mum temporal to the fovea. Results: The outer nuclear layer was most severely attenuated in eyes with disciform scars, demonstrating a 69.4% reduction in cell number relative to control eyes. A loss in retinal ganglion cells (by 7.3%) and an increase in inner nuclear layer cells (by 10%) were observed, but these changes were not significant. Photoreceptor loss was most pronounced when the disciform scar was not covered by the retinal pigment epithelium. Conclusion: The nuclei of the outer nuclear layer are significantly attenuated in eyes with disciform age-related macular degeneration, while the ganglion cell and inner nuclear layers are relatively preserved. These findings suggest that replacement of outer nuclear function, by either retinal transplantation or implantation of the intraocular retinal prosthesis, might be a feasible therapeutic option for patients with this condition.