title: Global prevalence of glaucoma and projections of glaucoma burden through 2040: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Glaucoma is the leading cause of global irreversible blindness. Present estimates of global glaucoma prevalence are not up-to-date and focused mainly on European ancestry populations. We systematically examined the global prevalence of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG), and projected the number of affected people in 2020 and 2040.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  Data from 50 population-based studies (3770 POAG cases among 140,496 examined individuals and 786 PACG cases among 112 398 examined individuals).
  
  
  METHODS
  We searched PubMed, Medline, and Web of Science for population-based studies of glaucoma prevalence published up to March 25, 2013. Hierarchical Bayesian approach was used to estimate the pooled glaucoma prevalence of the population aged 40-80 years along with 95% credible intervals (CrIs). Projections of glaucoma were estimated based on the United Nations World Population Prospects. Bayesian meta-regression models were performed to assess the association between the prevalence of POAG and the relevant factors.
  
  
  METHODS
  Prevalence and projection numbers of glaucoma cases.
  
  
  RESULTS
  The global prevalence of glaucoma for population aged 40-80 years is 3.54% (95% CrI, 2.09-5.82). The prevalence of POAG is highest in Africa (4.20%; 95% CrI, 2.08-7.35), and the prevalence of PACG is highest in Asia (1.09%; 95% CrI, 0.43-2.32). In 2013, the number of people (aged 40-80 years) with glaucoma worldwide was estimated to be 64.3 million, increasing to 76.0 million in 2020 and 111.8 million in 2040. In the Bayesian meta-regression model, men were more likely to have POAG than women (odds ratio [OR], 1.36; 95% CrI, 1.23-1.52), and after adjusting for age, gender, habitation type, response rate, and year of study, people of African ancestry were more likely to have POAG than people of European ancestry (OR, 2.80; 95% CrI, 1.83-4.06), and people living in urban areas were more likely to have POAG than those in rural areas (OR, 1.58; 95% CrI, 1.19-2.04).
  
  
  CONCLUSIONS
  The number of people with glaucoma worldwide will increase to 111.8 million in 2040, disproportionally affecting people residing in Asia and Africa. These estimates are important in guiding the designs of glaucoma screening, treatment, and related public health strategies.
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore.
authors: Yih-Chung
authors: YC
authors: Tham
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Statistics and Applied Probability, National University of Singapore, Singapore.
authors: Xiang
authors: X
authors: Li
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore.
authors: Tien Y
authors: TY
authors: Wong
authors: Glaucoma Service and Dana Center for Preventive Ophthalmology, Wilmer Ophthalmological Institute, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors: Harry A
authors: HA
authors: Quigley
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore.
authors: Tin
authors: T
authors: Aung
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore; Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore; Duke-NUS Graduate Medical School, Singapore. Electronic address: ching-yu_cheng@nuhs.edu.sg.
authors: Ching-Yu
authors: CY
authors: Cheng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000517:prevention & control; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000453:epidemiology*; D005902:Glaucoma, Open-Angle / Q000453:epidemiology*; D014943:Global Health / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence