Incidence of exudative age-related macular degeneration among elderly Americans

Purpose: To estimate the 3-year incidence of exudative age-related macular degeneration (AMD) and its treatment by laser photocoagulation in elderly Americans. Design: Population-based cohort study using insurance claims data. Participants: A random 5% sample of Medicare beneficiaries, age 65 and older. Methods: Incidence of exudative AMD and of laser photocoagulation for this condition was assessed based on four categories of ascertainment criteria that included procedure and diagnosis codes associated with exudative AMD, choroidal neovascularization, and its treatment. Main Outcome Measures: Incidence of AMD and of associated laser photocoagulation. Results: Overall, the 3-year incidence of exudative AMD is estimated to be between 9.4 per 1000 and 11.4 per 1000 Americans age 65 and older (depending on ascertainment criteria), based on those diagnosed and treated by ophthalmologists for the condition. These estimates bracket the measured incidence of exudative AMD in the Beaver Dam Eye Study and lie within its 95% confidence interval. The 3-year incidence of exudative AMD with attendant laser photocoagulation was 2.3 per 1000. Women were found to have a slightly higher incidence of AMD than men using all ascertainment criteria (P <0.001), and white Americans were found to have a fivefold-to-sixfold higher ascertainment criteria than black Americans (P <0.001). Conclusions: The reported incidence of exudative AMD identified in the population of Medicare beneficiaries suggests that measurements on incidence for this condition derived from the Beaver Dam Eye Study can be generalized to the U.S. population.