National, regional, and provincial prevalence of age-related macular degeneration in China in 2020: an updated systematic review and modelling study.

Background: The burden of age-related macular degeneration (AMD) has steadily increased in recent decades. We aimed to estimate the prevalence of AMD, including its subtypes, among individuals aged 40-89 years in China. Methods: We conducted an updated literature search in the CNKI, Wanfang, Chinese Science and Technology Journal Database, PubMed, Embase, and MEDLINE for studies published between 27 June 2016 and 30 July 2024 that reported on the prevalence of AMD in China. We also included data from the 2017 China AMD Study. We utilised a multi-level mixed-effects meta-regression model to estimate age- and sex-specific prevalence of any AMD and its subtypes at the national level. For any AMD, we additionally conducted random-effects meta-analyses to pool odds ratios for associated factors, after which we incorporated these estimates into an associated factor-based model to estimate prevalence at regional and provincial levels. Results: We included 40 articles, of which 24 contributed data for modelling analysis. The estimated national prevalence in China in 2020 was 4.70% (95% CI = 3.40, 6.46) for any AMD, 4.06% (95% CI = 2.92, 5.60) for early AMD, and 0.64% (95% CI = 0.48, 0.86) for late AMD, including 0.30% (95% CI = 0.25, 0.37) for geographic atrophy and 0.34% (95% CI = 0.23, 0.49) for neovascular AMD. These corresponded to 32.42 million cases (95% CI = 23.43, 44.54) with any AMD, 28.00 million (95% CI = 20.15, 38.61) with early AMD, 4.42 million (95% CI = 3.28, 5.93) with late AMD, 2.09 million (95% CI = 1.71, 2.52) with geographic atrophy, and 2.33 million (95% CI = 1.57, 3.41) with neovascular AMD. Regionally, the highest prevalence and number of cases was observed in Southwest China (5.95%; 95% CI = 4.48, 7.81) and South Central China (10.68 million; 95% CI = 7.60, 14.82), respectively. At the provincial level, Hainan and Guangdong exhibited the highest prevalence (7.64%; 95% CI = 4.61, 12.22) and the largest number of individuals affected (3.50 million; 95% CI = 2.34, 5.13), respectively. Conclusions: We observed a substantial burden of AMD in Mainland China, with variations across subtypes, regions, and provinces. These findings underscore a need for targeted public health strategies to address AMD in the context of ageing. Registration: PROSPERO: CRD420251080685.