Prevalence and risk factors for age-related macular degeneration in an adult Japanese population: the Funagata study.

OBJECTIVE: To describe the prevalence and risk factors for age-related macular degeneration (AMD) in a Japanese population and to compare these with data from a white population.

DESIGN: Population-based cross-sectional epidemiologic study.

PARTICIPANTS: A population-based sample of Japanese persons 35 years or older from Funagata, Japan.

METHODS: The Funagata study is a population-based study of 1758 (43% of eligible) Japanese persons 35 years or older from Funagata, Japan. In 2000 to 2002, 1625 (92.4%) participants had a nonmydriatic fundus photograph of one eye with sufficient quality for grading of AMD lesions, using the Wisconsin protocol. Age-standardized prevalence rates compared with the Blue Mountains Eye Study (BMES) population, odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Risk factors were assessed by logistic regression.

MAIN OUTCOME MEASURES: Early and late AMD.

RESULTS: Of 1625 participants, early AMD and late AMD were present in 3.5% and 0.5%, respectively. Age-standardized early AMD prevalence in right eyes was 4.1%, similar to the corresponding prevalence of 4.4% in the BMES. For men, age-standardized prevalences of late AMD in right eyes were 1.1% and 1.2% in the BMES; for women, the corresponding prevalences were 0.3% and 2.1%, respectively. Increasing age (per 10 years; gender-adjusted OR, 2.27; 95% CI, 1.10-4.67) and current cigarette smoking (age- and gender-adjusted OR, 5.03; 95% CI, 1.00-25.47) were associated with late AMD.

CONCLUSIONS: In this Japanese population, prevalence of early AMD was similar to that for whites in the BMES. Although the late AMD prevalence was lower in Japanese women, in Japanese men it was similar to that in whites. This could have resulted from the substantially high proportion of Japanese men who are smokers. Cigarette smoking and increasing age were the 2 principal factors found associated with late AMD.