Risk factors for age-related maculopathy - The Visual Impairment Project

Objective: To describe the risk factors and associated population attributa ble risk for age-related maculopathy (ARM) and age-related macular degenera tion (AMD) in Australians aged 40 years and older. Methods: Residents were recruited from 9 randomly selected urban clusters a nd 4 randomly selected rural clusters in Victoria, Australia. At locally es tablished test sites, the following information was collected: visual acuit y, medical and health history, lifetime sunlight exposure, dietary intake, and fundus photographs. Age-related maculopathy and AMD were graded from th e fundus photographs using an international classification and grading syst em. Backwards logistic regression was used to identify the independent risk factors for ARM and AMD. Results: The participation rate was 83% (n=3271) among the urban residents and 92% (n= 1473) among the rural residents. Gradable fundus photographs of either eye were available for 4345 (92%) of the 4744 participants. There w ere 656 cases of ARM, giving a weighted prevalence of 15.1% (95% confidence limit [CL], 13.8, 16.4); and there were 30 cases of AMD, giving a weighted prevalence of 0.69% (95% CL, 0.33, 1.03). In multiple logistic regression, the risk factors for AMD were as follows: age (odds ratio [OR], 1.23; 95% CL, 1.17, 1.29), smoked cigarettes for longer than 40 years (OR, 2.39; 95% CL, 1.02, 5.57), and ever taken angiotensin-converting enzyme inhibitors (O R, 3.26; 95% CL, 1.33, 8.01). The magnitude of all of these risk factors wa s slightly less for ARM, and having ever taken blood cholesterol-lowering m edications was also significant (OR, 1.67; 95% CL, 1.12, 2.47; P = .001). Conclusion: Smoking is the only modifiable risk factor for ARM and AMD, amo ng the many environmental and systemic factors that were assessed.