Abstract
Purpose: :
We compared the proportion of bilateral involvement of early and late age-related macular degeneration (AMD) between Asian Malays and Caucasians.
Methods: :
We used the baseline examination data for subjects aged 50-79 years in the Singapore Malays Eye Study (SiMES) (n=2,453) and the Blue Mountains Eye Study (BMES) (n=3,265). Prevalence of bilateral cases was directly age-standardized to the world population. Presence of early, late AMD and individual lesions was determined by grading of fundus images using a modification of the Wisconsin Age-related maculopathy grading system. Bilateral involvement was defined for early, late AMD and each lesion type.
Results: :
Early/late AMD was observed in 156(6.4%)/21(0.9%) and 185(5.7%)/37(1.1%) subjects in the SiMES and the BMES, respectively. Proportions with bilateral early AMD or early AMD lesions were comparable between the two populations. Age-standardized frequency of bilateral early AMD was 24.6%, 95% Confidence Interval [CI] 15.6-33.3% in the SiMES, compared to 27.8%, 95%CI 17.3-38.3% in the BMES. Although not statistically significant, bilateral late AMD was less frequent in the SiMES (age-standardized frequency 6.9%, 95% CI 2.4-11.4% vs. 32.9%, 95% CI 1.0-66.7% in the BMES). Among men, bilateral neovascular AMD (0% vs. 33.3%; p<0.001) and bilateral geographic atrophy (41.7% vs. 50.0%; p=0.03) both were both less frequent in the SiMES than in BMES. In women, however, these frequencies were similar between the two populations.
Conclusions: :
In a comparison of Asian Malays to Caucasians, the frequency of bilateral early AMD was similar but the frequency of bilateral late AMD in men was substantially different. A lower frequency of bilateral neovascular AMD in Malays may reflect different clinical characteristics and presentation of late AMD between Asians and Caucasians, given that polypoidal choroidal vasculopathy presents more commonly in Asian men and is more frequently unilateral.
Keywords: age-related macular degeneration