Global burden of age-related macular degeneration, with forecast up to 2050: a modelling study.

TOPIC: We aimed to estimate the prevalence of age-related macular degeneration (AMD) using a single standardized classification and provide comparable global, regional, and national burden estimates from 1990 to 2050. CLINICAL RELEVANCE: Owing to the marked heterogeneity in AMD classification criteria across the included studies, there remains a need to delineate the burden of AMD using a unified and standardized classification system. METHODS: Following registration (CRD420251067039), a search was conducted in PubMed/MEDLINE, Embase, CINAHL, and Google Scholar. Eligible epidemiological studies reporting AMD prevalence were included, and extracted prevalence data were harmonized according to the Beckman classification. An expectation-maximization algorithm was applied to disaggregate data into early, intermediate, geographic atrophy (GA), and neovascular AMD (nAMD). Prevalence was modeled for 204 countries and territories using DisMod-MR, with projections to 2050 using a hybrid machine learning approach, including scenario analyses of tobacco reduction and increased physical activity. Estimates were stratified by clinical stage and ethnicity with 95% uncertainty intervals (UIs). Prevalence of AMD stratified by clinical stage (early, intermediate, geographic atrophy [GA], and neovascular AMD [nAMD]), age, sex, and ethnicity across 204 countries from 1990 to 2021, with projections and risk-reduction scenarios through 2050. RESULTS: In 2021, the global prevalence of AMD across all stages was 10.03% (95% UI, 8.30-12.06); early AMD, 5.40% (4.72-6.14); intermediate AMD, 4.01% (3.41-4.66); GA, 0.32% (0.26-0.39); and nAMD, 0.31% (0.26-0.36). Prevalence increased from 1990 to 2021, whereas age-standardized rates declined. AMD prevalence rose sharply with age, with no significant sex differences in early or intermediate AMD. GA prevalence was highest among Hispanic populations, and nAMD among European populations. Projections indicate continued increases through 2050, with reductions under tobacco reduction and increased physical activity scenarios. CONCLUSIONS: This study provides the first global, regional, and national prevalence estimates of AMD stratified by the Beckman classification, offering evidence to inform clinical practice and health policy.