A major goal of the proposed study is to develop prognostic tests for exudative age-related macular degeneration (AMD). Two types of prognostic tests and risk factors will be evaluated and compared: tests of visual function, and indices and descriptors of fundus appearance. To develop prognostic tests, a large number of eyes will be followed prospectively that 1) have already been tested with a battery of visual function tests previously shown to reveal pathology, 2) have already had their fundi photographed, and 3) are known to have relatively high incidence rates of exudative AMD, for their fellow eye has exudative AMD. The visual function tests include a) dark adaptation, b) color matching, c) absolute sensitivity, d) S cone sensitivity, and e) acuity in the fellow eye that already has exudative AMD. Aspects of fundus appearance will be quantified to the extent possible and evaluated separately for the fovea and macula, to test the hypothesis that foveal appearance is a better risk indicator for exudative AMD than is macular appearance. Another goal of this study is to answer questions that have arisen from cross-sectional results of the current study,k both for eyes whose fellow eye has exudative AMD and for eyes of people with good bilateral acuity. Generalizability of results from subjects who have unilateral exudative AMD and good acuity will be evaluated by testing subjects who have reduced acuity. At the conclusion of the study, all interested subjects will be enrolled in a retinal donor program, so that eyes with extensively documented functional and funduscopic histories eventually may be examined neuroanatomically, immunocytochemically and histopathologically by other scientists. One unanticipated result from the studies of aging will be addressed through experiments derived also from concurrent basic studies of adaptation. That is, the profound reductions of flicker sensitivity found for moderate chromatic adaptation conditions among elderly people who probably had undiagnosed glaucoma will be investigated in parallel with the losses of flicker sensitivity that occur for more extreme adaptation conditions for young normal subjects. In particular, the profound reductions of flicker sensitivity will be investigated from the perspective that flicker sensitivity losses can depend on cone spectral opponency, rather than on sensitivity reduction of a strictly achromatic pathway. Test and adaptation parameters will be varied systematically to determine whether profound reductions of flicker sensitivity among the elderly correspond to flicker sensitivity losses for young normal subjects. The long term objective is to develop a screening test for low tension glaucoma.
