Ethnic Variation in Early Age-Related Macular Degeneration Lesions Between White Australians and Singaporean Asians

PURPOSE. We compared early age-related macular degeneration (AMD) lesion characteristics between white Australians and Singaporean Asians. METHODS. Participants of the Blue Mountains Eye Study (BMES; whites, n = 3508) and the Singapore Epidemiology of Eye Disease Study (SEED; Malay, n = 3280, Indian, n = 3400, and Chinese, n = 3353) underwent examinations, including retinal photography. The AMD lesions were assessed following the Wisconsin AMD grading protocol by the same photographic grader. Prevalence and characteristics of early AMD lesions were compared between the BMES and the SEED. The associations between ethnicity and early AMD lesion types were analyzed using logistic regression models adjusting for age, sex, smoking status, lipids, and genetic polymorphisms associated with AMD. RESULTS. After age-standardization to the BMES population, the prevalence of distinct soft drusen was significantly higher in Singaporeans compared to Australians (23.9%, 95% confidence interval [CI] 22.9-25.0 vs. 6.2%, 95% CI 5.3-7.0), with an adjusted odds ratio (OR) of 4.6 (95% CI 3.4-6.0). In contrast, the prevalence of indistinct soft or reticular drusen was significantly lower in Singaporeans compared to Australians (6.5%, 95% CI 5.9-7.1 vs. 8.3%, 95% CI 7.4-9.3, with nonsignificant adjusted OR of 1.2, 95% CI 0.8-1.7). Soft drusen of any type were present frequently at the inner and outer macula (within a zone >= 500 to <3000 mu m radius from the foveal center) among Singaporeans, while among Australians soft drusen were present more frequently at the central macula (<500 mu m radius). CONCLUSIONS. Singaporean Asians had a milder spectrum of early AMD lesions and lesion characteristics (predominantly distinct soft drusen and noncentral location) compared to white Australians.