To obtain the prevalence of glaucoma and its characteristics in China: a meta analysis from 1980 to the present.

The epidemiological studies on glaucoma in community populations in China from 1980 to 2020 were reviewed and a meta-analysis was carried out. Pubmed ScienceDirect, Wan Fang database and CNKI database were searched using glaucoma, primary glaucoma, primary open-angle glaucoma (POAG), and primary angle-closure glaucoma (PACG). Two researchers independently screened the literatures and extracted the prevalence, blinding rate (BR), and proportion of blindness caused by glaucoma in irreversible blindness cases (GB ratio), and then were calculated. The data of 1990 was the summary of studies published in 1980 to 1990, and so on until 2020. The inter-study heterogeneity evaluation was conducted with the Q test and I² test. If P<0.05 or I²>50%, the heterogeneity is considered large, and the random effect model was used; otherwise, the fixed effect model would be used. The characteristics of the abovementioned parameters was represented by a descriptive statistical analysis.

After preliminary search, 4440 publications were obtained and then the deduplication, non-related abstract and full-text were excluded. Finally, 60 publications on studies carried out in 23 provinces and municipalities were included, including 26 studies carried out in19 provinces and municipalities on the prevalence and BR, and 34 studies carried out in 17 provinces and municipalities on the GB ratio. In 1990, the prevalence of glaucoma and primary glaucoma was 0.5% (95%CI: 0.5% to 0.6%, I²=7%, P>0.05) and 0.5% (95%CI: 0.4% to 0.6%, I²=7%, P>0.05), which has been increasing ever since. In 2020, the prevalence of glaucoma and primary glaucoma dropped compared with that in 2010 and was 2.5% (95%CI: 2.2% to 2.8%, I²=85%, P<0.05) and 2.2% (95%CI: 1.6% to 2.5%, I²=89%, P>0.05). The prevalence of PACG increased from 0.4% in 1990 increased to 1.7% in 2010 and then decreased to 1.1% in 2020, while the prevalence of POAG has increased year by year, from 0.1% in 1990 to 0.3% in 2010, followed by a significant increase to 1.1% in 2020. Since 1990, the proportion of PACG cases in all glaucoma cases has decreased year by year, from 80% to 43.8% in 2020, while the proportion of POAG cases has increased annually, from 20% in 1990 to 43.8%, and the proportion of other types of glaucoma has also increased annually from 2% in 2010 to 12.4% in 2020. BR increased from 24.4% (95%CI: 16.7% to 34.4%, I²=0%, P>0.05) in 1990 to 31.7% in 2000 (95%CI: 24.5% to 39.8%, I²= 0%, P>0.05) and then decreased to 24.1% in 2020 (95%CI: 19.9% to 29.2%, I²=58%, P>0.05). BR of PACG increased from 36.8% in 1990 to 63.1% in 2000 and then decreased to 26.2% in 2010 and 25.7% in 2020, with a steady development. BR of POAG remained relatively stable in the past 4 decades, ranging from 12.4% to 17.4%. In addition, GB ratio has a biggest decline of 62.2%, from 59.6% in 1990 to 2020.

Population ageing and the advancement of glaucoma screening and diagnosis have contributed to the increase in the prevalence of glaucoma in China. The decline in the prevalence of PACG is closely related to the popularization of cataract surgery techniques. With the nationwide promotion of the prevention and treatment system based on etiological classification and precise diagnosis and treatment, BR of PACG has significantly reduced. The high prevalence of POAG in recent years may be a result of the improvement in and popularization of glaucoma screening techniques. In future, more efforts should be made to research and promote POAG diagnosis and treatment techniques.