Is bilateral age-related macular degeneration less common in Asians than Caucasians?

To compare the frequency and pattern of bilateral involvement of early and late age-related macular degeneration (AMD) between Asian Malays and Caucasians.

We used cross-sectional data from the baseline examination for subjects aged 50-79 years in the Singapore Malay Eye Study (SiMES) (N = 2,453) and the Blue Mountains Eye Study (BMES) (N = 3,265). We assessed AMD signs using a common protocol modified from the Wisconsin Age-related Maculopathy Grading System at the University of Sydney. We compared frequencies or proportions of AMD cases with bilateral involvement between the two populations.

There were 173 cases and 169 cases with any AMD (either early or late AMD in at least one eye), and 78 cases (45.1%) and 52 cases (30.8%) with bilateral AMD in the BMES and the SiMES, respectively. Age-standardized frequency of bilateral involvement was comparable between the BMES (29.5%, 95% confidence interval(CI) 18.5-40.5%) and the SiMES (25.6%, 95%CI 17.0-34.0%). Older age was associated with higher risk of bilateral AMD (gender-adjusted odds ratio per 1 year for the BMES and the SiMES: 1.08 [95% CI 1.05-1.11] and 1.06 [95% CI 1.02-1.10], respectively).

The frequency of bilateral AMD was comparable between Asian Malays in the SiMES and the Caucasian population of the BMES. Other than older age, we did not find any characteristics associated with the bilateral involvement of AMD.