Focal electro-oculogram in age-related macular degeneration

Age-related macular degeneration (AMD) is an important cause of vision loss among the elderly. Because patients with early subretinal neovascular membranes due to AMD can be treated by laser photocoagulation it becomes critical to find tests which can detect early changes. Inasmuch as AMD involves the retinal pigment epithelium, one might expect the electro-oculogram (EOG) to be sensitive to AMD pathology, but the ganzfeld EOG has been found to be normal in most cases. We designed a focal EOG apparatus to try to emphasize the contribution of the central retina, where AMD is found, to the EOG. Seventeen patients with various stages of drusen and AMD were tested and compared with normals. The focal EOG did not separate the AMD patients from the normals, nor did it give different distributions for the various subgroups of AMD. The focal EOG, like the ganzfeld EOG, is not a sensitive test for AMD.