Purpose
To update the prevalence of primary open angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) in Asia and project the number of people with glaucoma in 2020 and 2040.
Methods
A systematic literature review was conducted to identify all population-based studies of glaucoma in Asia and only studies using standardized glaucoma diagnosis schemes were included in the meta-analysis. Hierarchical Bayesian (HB) approaches were used to determine the pooled prevalence of glaucoma, and examine the difference in prevalence by gender, geographic regions and urban/rural subgroups. The number of people with glaucoma in 2020 and 2040 was projected based on the database from the United Nations World Population Prospects. The difference of Deviance Information Criterion (dDIC) was calculated as a measure of substantial evidence to support a prevalence difference if dDIC ≥ 5. Otherwise, the posterior probability (PP) (PP close to 1 suggest moderate evidence) of the difference in prevalence was used.
Results
We identified 21 studies (n = 64,046 individuals) conducted between 1996 and 2010. The pooled prevalence for POAG, PACG and total glaucoma were 2.01%, 0.89% and 2.96%, respectively. Compared to males, females were less likely to have POAG (1.82% vs. 2.51%, dDIC=21.8), but more likely to have PACG (1.07% vs. 0.57%, dDIC=40.2). Overall, the prevalence of glaucoma was higher in males than females (2.91% vs. 3.30%, PP=0.98). The prevalence of POAG was higher in urban than in rural environments (3.52% vs. 1.57%, PP=0.98). PACG is more prevalent in East Asia than South Asia (1.22% vs. 0.65%, PP=0.99). The projected number of people with glaucoma in Asia is 49.9 million in 2020 (POAG 76.1%), and 76.8 million in 2040 (POAG 69.6%) with balanced gender ratio (females: 51.0%, 2020; 50.3%, 2040). Simulation study was performed and showed that estimation using HB approach was unbiased and the method of generalized estimating equations used in previous studies overestimated the pooled prevalence.
Conclusions
The prevalence and incidence projections reflect the significant burden of glaucoma in Asia. There is substantial evidence to support the effect of gender and moderate evidence for geographic regions and urban environments on the risk of glaucoma. These estimates provide important information for the design and implementation of eye care programs for glaucoma in Asia.
Keywords: 459 clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology •
463 clinical (human) or epidemiologic studies: prevalence/incidence •
412 age-related macular degeneration