Objective: To investigate the prevalence of and risk factors for age-related maculopathy (ARM) in three racial/ethnic groups: non-Hispanic whites, non-Hispanic blacks, and Mexican-Americans.
Design: A nationally representative population-based, cross-sectional study.
Participants: A total of 8270 persons 40 years of age or older, a sample of the Third National Health and Nutrition Examination Survey.
Main outcome measures: Age-related maculopathy was determined by the grading of fundus photographs using a standardized protocol.
Results: The prevalence of any ARM in the civilian noninstitutionalized United States population including those 40 years of age or older was 9.4% (95% confidence interval [CI], 8.2, 10.6) as estimated from the sample. After adjusting for age, there was no difference in the prevalence of early ARM (defined largely by the presence of soft drusen) by ethnic/racial group. However, for the less frequent component lesions of early ARM (increased retinal pigment and retinal pigment epithelial depigmentation), the odds ratios (95% CIs) comparing non-Hispanic blacks to non-Hispanic whites were 0.47 (0.31, 0.74) and 0.59 (0.33, 1.04), respectively, and for comparing Mexican-Americans to non-Hispanic whites, they were 0.41 (0.21, 0.81) and 0.72 (0.44, 1.19), respectively. For late ARM, the odds ratio (95% CI) for non-Hispanic blacks compared to non-Hispanic whites was 0.34 (0.10, 1.18) and for Mexican-Americans compared to non-Hispanic whites, it was 0.25 (0.07, 0.90). Other than age, none of the personal, medical, or physiologic variables studied were statistically significantly associated with any of the ARM endpoints in any of the three races/ethnic groups.
Conclusion: Overall, rates of any ARM (including all early and late lesions) are not significantly different among non-Hispanic blacks, Mexican-Americans, and non-Hispanic whites. However, the rates of individual lesions suggest that non-Hispanic whites and Mexican-Americans may be protected against retinal pigment abnormalities and lesions associated with late ARM. There appears to be little influence of personal, medical, and environmental factors studied on these results. Further studies in larger populations of older persons in these ethnic groups would likely clarify these relations.