Prevalence and incidence
The prevalence (total number of individuals with a disease at a specific time) and incidence (number of new cases that develop during a specific period) of POAG vary widely across population-based samples owing to differences in ethnic and racial representation (Fig 3-1). In the Baltimore Eye Survey, the prevalence of POAG among white individuals ranged from 0.9% in those aged 40–49 years to 2.2% in those aged ≥80 years, whereas the prevalence among black individuals ranged from 1.2% to 11.3%, respectively. The overall population-based prevalence was 4–5 times higher among black individuals than white individuals.
In the Rotterdam Study, a longitudinal population-based study of northern Europeans, the observed prevalence was 1.1% among subjects ≥55 years of age. In the same study cohort, the incident risk of developing glaucoma at 10 years was 2.8%. In both the Baltimore Eye Survey and the Rotterdam Study, half of the subjects with glaucoma were unaware of their diagnosis.
The prevalence of glaucoma in the Barbados Eye Study (a predominantly African Caribbean population) was 7% in individuals ≥40 years, and the 4-year incidence of glaucoma was 2.2%. Again, older age was found to be a major risk factor for the prevalence and incidence of glaucoma.
The observed prevalence of OAG in the Los Angeles Latino Eye Survey (LALES), a longitudinal population-based study of Latinos (mostly Mexican ancestry) ≥40 years of age, was 4.7%, with 75% unaware of their diagnosis at baseline. The prevalence among those 80 years or older was nearly 22%. The 4-year incidence rate of OAG was 2.3%.
In the Tajimi Study (Japan), the prevalence of POAG among subjects ≥40 years was 3.9%. The IOP was ≤ 21 mm Hg in 92% of those with POAG. The mean IOP in the nonglaucomatous eyes was 14.5 ± 2.5 mm Hg, about 2 mm Hg lower than observed in European-derived populations.
A meta-analysis estimated the global prevalence of POAG in 2013 to be 3.0% among persons 40–80 years of age. In this age group, the highest prevalence of POAG, an estimated 4.2%, is found in Africa. The same study estimated the prevalence of POAG in North America to be approximately 3.3%.
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Leske MC, Connell AM, Wu SY, et al. Incidence of open-angle glaucoma: the Barbados Eye Studies. The Barbados Eye Studies Group. Arch Ophthalmol. 2001;119(1):89–95.
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Tham YC, Li X, Wong TY, Quigley HA, Aung T, Cheng CY. Global prevalence of glaucoma and projections of glaucoma burden through 2040: a systematic review and meta-analysis. Ophthalmology. 2014;121(11):2081–2090.
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Tielsch JM, Sommer A, Katz J, Royall RM, Quigley HA, Javitt J. Racial variations in the prevalence of primary open-angle glaucoma. The Baltimore Eye Survey. JAMA. 1991;266(3):369–374.
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Varma R, Ying-Lai M, Francis BA, et al; Los Angeles Latino Eye Study Group. Prevalence of open-angle glaucoma and ocular hypertension in Latinos: the Los Angeles Latino Eye Study. Ophthalmology. 2004;111(8):1439–1448.
Risk factors
Population-based studies and prospective glaucoma clinical trials have identified a number of risk factors that are associated with POAG diagnosis and progression. The most widely accepted risk factors include higher IOP; lower ocular perfusion pressure; older age; lower central corneal thickness (thinner cornea); high myopia; and racial, ethnic, and genetic susceptibility. Other possible risk factors are discussed in Chapter 7.
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Leske MC, Heijl A, Hyman L, Bengtsson B, Dong L, Yang Z; EMGT Group. Predictors of long-term progression in the Early Manifest Glaucoma Trial. Ophthalmology. 2007;114(11):1965–1972.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.