Prevalence of age-related macular degeneration.

Early and late age-related macular degeneration (AMD) have a high prevalence in elderly patients but may be differentiated by medical or environmental factors, eg, hypertension, geographic area, or antioxidant agents. Because nuclear sclerotic cataract is associated with AMD both aging changes may share a common pathogenesis. The genetic predisposition for AMD is indicated by the identical appearance in monozygotic twins, but genetics may be also important for the explanation of the low incidence of late AMD in black individuals. Specific ocular characteristics like light or depigmented iris color, prolonged dark adaptation, and decreased foveal flicker sensitivity are also risk factors for AMD. Early AMD characteristics with high risk for late AMD are confluent drusen, focal hyperpigmentation, or atrophy and slow choroidal fluorescein filling. Therefore specific genetic, environmental, medical, and ocular characteristics determine the individual appearance and progress of AMD. The knowledge of these factors may result in new prophylactic and specific treatments for AMD.