Purpose: To determine the number of neurons remaining in the ganglion cell layer (GCL) of eyes with nonexudative and exudative age-related macular degeneration (NEAMD and EXAMD, respectively) in relation to photoreceptor loss in the same retinas.
Methods: The study design was a clinicopathologic correlation. Macular photoreceptors and GCL neurons were counted in unstained retinal wholemounts from eyes of patients with NEAMD (n = 6) and EXAMD (n = 5) and from control patients without grossly visible drusen or pigmentary change (n = 15; age range, 60-95 years). The authors determined the percentage of counting sites with significant cell loss relative to control eyes and for photoreceptors, the percentage of sites where rod or cone loss predominated. The total numbers of cones, rods, and GCL neurons were determined within the 6-mm-diameter macula. Fellow eyes were prepared for light and electron microscopic evaluation of retinal pigment epithelium and Bruch's membrane disease.
Results: EXAMD eyes had severe photoreceptor loss. The total number of macular photoreceptors in NEAMD eyes was similar to the number in control eyes, despite moderate loss in the parafovea. In 9 of 11 AMD eyes, rod loss was greater than cone loss at the same locations. EXAMD eyes had 47% fewer GCL neurons than control eyes. GCL neurons in NEAMD eyes did not differ significantly from control eyes.
Conclusions: Interventions targeted at the outer retina early in the progression of neovascular disease should benefit from the full age-appropriate complement of GCL neurons.