The prevalence of age-related maculopathy by geographic region and ethnicity - The Colorado-Wisconsin study of age-related maculopathy

Objectives: To determine the prevalence of age-related maculopathy (ARM) in a biethnic population and to determine if there are ethnic and/or geographic differences in the prevalence of ARM. Design: Prevalence data from 2 population-based studies, the San Luis Valley Diabetes Study (n=1541, ages 21-74 years) and the Beaver Dam Eye Study (n=3999, ages 43-74 years), were compared. Setting: Southern Colorado and central Wisconsin. Main Outcome Measurer Color stereoscopic fundus photographs were graded for ARM using the Wisconsin Age-related Maculopathy Grading System. Similar questionnaire, laboratory, and clinical data on potential risk factors were available from both studies. Results: Late-stage ARM was significantly less frequent among Hispanics than non-Hispanic whites (NHW) in Beaver Dam (odds ratio [OR]=0.07; 95% confidence interval [CI]=0.01-0.49; Hispanics vs Beaver Dam NHW). The prevalence of any ARM was significantly lower among San Luis Valley NHW (10.4%) than Beaver Dam NHW (14.3%) (OR=0.67; 95% Cl=0.50-0.91). This prevalence difference was not explained by any of the risk factors examined (smoking, cardiovascular disease, diabetes, alcohol consumption, etc). The 2 NHW groups reported different European heritages. Conclusions: Late-stage ARM appeared to be rare among Hispanics but there was no ethnic difference in prevalence of any ARM. The 33% difference in risk among NHW by geographic location was not reduced when controlling for possible risk factors or confounders, suggesting that genetic heritage may be an important determinant of risk for ARM.