Prevalence and Pattern of Geographic Atrophy in Asia: the Asian Eye Epidemiology Consortium

Abstract

OBJECTIVE: Although there have been many population-based studies of age-related macular degeneration (AMD) only limited information is available in Asia on the epidemiology of geographic atrophy (GA). We aimed to determine the prevalence and patterns of GA through an analysis of multiple studies conducted within the Asian Eye Epidemiology Consortium (AEEC). DESIGN: Cross-sectional meta-analyses. PARTICIPANTS: A total of 97,213 individuals aged 40 years and older. METHODS: Data from 22 population-based studies from countries belonging to the AEEC were included. In all studies, AMD was defined based on standardized grading systems. GA was defined as an area of pallor in the fundus with visibility of the underlying choroidal blood vessels and sharply defined borders. Random-effects meta-analysis was performed to estimate overall, age-, gender-, and region-specific pooled prevalence of GA. MAIN OUTCOME MEASURES: Prevalence of GA per 1000 persons RESULTS: The mean age was 60.8 +/-10.8 years, 42,673 (43.9%) were males. Overall, a total of 223 (0.2%) individuals had GA. The pooled overall prevalence of GA was 1.57 per 1000 persons (95% Confidence Interval [CI], 1.04-2.10), which was three times less than that of neovascular AMD of 5.20 per 1000 persons (95% CI, 3.97-6.43). Compared to those aged 50-59 years, the prevalence of GA rose from 0.34 per 1,000 persons (95% CI, 0.07-0.62) to 2.94 per 1,000 persons (95% CI, 1.60-4.29) in those aged >/=70 years. The GA prevalence per 1000 persons was similar between urban (2.22 [95% CI, 1.23-3.23]) and rural residents (1.55 [95% CI, 0.87-2.23]). GA was more prevalent in South Asia (based on studies from India and Nepal, 3.78 per 1,000 persons; 95% CI, 1.67-5.89), compared to East Asia (based on studies from China, Korea, and Japan, 0.76 per 1000 persons; 95% CI, 0.31-1.22, P=0.006). CONCLUSIONS: GA is uncommon in Asian populations compared to those of European ancestry. Even within Asia geographical differences in GA prevalence were seen. The findings of this meta-analysis suggest that better dissection of risk factors in the Asian population for GA, and it may provide insights into the biological pathways that drive these late-stage manifestations, thus suggesting better targets for prevention.