National, regional, and provincial prevalence of glaucoma in China in 2020: an updated systematic review and modelling analysis

Background Glaucoma is the leading cause of irreversible blindness worldwide, with a significant disease burden in China. Accurate prevalence estimates are crucial for guiding public health strategies, but large-scale epidemiological investigations remain challenging due to the need for comprehensive ophthalmic assessments. Through a systematic review and modelling approach, we aimed to estimate the national, regional, and provincial prevalence of glaucoma in China in 2020. Methods We performed an updated systematic literature search of the China National Knowledge Infrastructure, Wanfang, the China Science and Technology Journal Database, PubMed, Embase, and MEDLINE for articles published from 19 August 2017 to 12 July 2024 that reported the prevalence of glaucoma in the general Chinese population. We also included articles from the 2017 China Glaucoma Study whose data collection period started in 2000 or later. We included articles that used optic disc examination and/or visual field assessment for diagnosis, and excluded those defining glaucoma solely by intraocular pressure measurement. We conducted age-sex splitting to enhance data availability for estimating the prevalence of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). We applied a multi-level mixed-effects meta-regression to estimate the prevalence of POAG and PACG at national and regional levels, adjusting for age, sex and study year, while we used an associated factor-based model to derive provincial prevalence estimates. We estimated the prevalence of secondary glaucoma and congenital glaucoma through random-effects meta-analyses. Results We included 43 articles comprising 286 577 participants. We estimated that the national prevalence of POAG among those aged 20–99 years in 2020 was 0.73% (95% confidence interval (CI) = 0.51, 1.03), equivalent to 7.88 million (95% CI = 5.58, 11.13) affected individuals in the mainland of China. We estimated PACG to be 0.81% (95% CI = 0.60, 1.10), equivalent to 8.79 million (95% CI = 6.50, 11.88) affected population. The prevalence of POAG and PACG both increased with age. The POAG prevalence was higher in males than in females across 20–99 years, while the PACG prevalence was higher in females. The POAG and PACG prevalence varied by region and province; the former was the highest in northeast China (0.77%, 95% CI = 0.55, 1.09) and the lowest in west China (0.71%, 95% CI = 0.50, 1.00), whereas the latter was the highest in central China (0.87%, 95% CI = 0.64, 1.17) and the lowest in east China (0.76%, 95% CI = 0.56, 1.02). Among 31 provinces or municipalities, Shanghai had the highest POAG prevalence (0.80%, 95% CI = 0.56, 1.12) and Tibet showed the lowest (0.56%, 95% CI = 0.40, 0.80). Regarding PACG, Sichuan had the highest prevalence (0.92%, 95% CI = 0.68, 1.25), whereas Beijing exhibited the lowest (0.56%, 95% CI = 0.42, 0.76). The pooled prevalence of secondary glaucoma and congenital glaucoma was 0.22% (95% CI = 0.16, 0.29) and 0.03% (95% CI = 0.00, 0.10), respectively. Conclusions The prevalence of glaucoma in China varied significantly across regions and provinces in our study period, highlighting the need for targeted screening programmes, early detection, and resource allocation. The modelling approach used here provides a valuable framework for estimating glaucoma prevalence in settings with limited large-scale epidemiological data. Registration PROSPERO: CRD420251005269.