Racial differences and other risk factors for incidence and progression of age-related macular degeneration: Salisbury Eye Evaluation (SEE) project

PURPOSE. To evaluate risk factors for the incidence and progression of age-related macular degeneration (AMD) in a racially heterogeneous, geriatric population. METHODS. Subjects (n = 2240) aged 65 to 84 years underwent 2 examinations separated by 2 years, of which 1937 subjects (85%) were included in this report. Fundus photographs were performed at each examination and were graded by trained readers. Multivariate logistic regression models adjusted for age, sex, race, and clustering between eyes were used to evaluate risk factors for AMD incidence and progression. RESULTS. Smoking was a strong, dose-dependent, risk factor for progression from medium size drusen to large drusen or pigmentary abnormalities within the central 1500-mu m macular zone. Smoking was also a strong risk factor for development of incident focal pigmentation within 3000 mu m of the foveal center. White participants were significantly more likely than blacks to develop large drusen and focal pigmentation and to progress from medium- to large-sized drusen or pigment abnormalities within the central 1500 mu m macular zone. However, whites did not have an increased risk of progression from large drusen or pigment abnormalities within the central 1500-mu m perimacular zone to foveal GA or CNV when compared with blacks. CONCLUSIONS. Smoking and race are important risk factors for progression from medium to large drusen or to pigment abnormalities within the central 1500-mu m macular zone. Limitations in the power of this study preclude assessment of the roles of smoking and race on the ultimate progression to foveal GA or CNV once central large drusen or pigment abnormalities are present.