Optic nerve and retinal ganglion cell (GC) degeneration are possible explanations for the poor visual function reported in patients with Alzheimer's disease (AD). We investigated whether GC loss could be attributed to AD compared with control subjects by measuring the spatial density of GC (cells/mm2) with methods previously used to analyze the GC distribution of young normal retinas. Retinas from 4 autopsy-confirmed, severely demented patients with AD and 4 age- and sex-matched control subjects (ages, 66-86 yr for both groups) without history of dementing or ocular disease were prepared as unstained whole mounts. There was no evidence for loss of GC within the central 43 degrees of vision in patients with AD. The density of GC subserving the central 11 degrees of vision was reduced by one-fourth in both AD and control eyes compared with retinas from young adults, as was GC density in a wedge of nasal retina. This loss may contribute to deficits in visual function found in aged individuals, whether or not they have dementia.