2020–2021 BCSC Basic and Clinical Science Course™
10 Glaucoma
Chapter 9: Primary Angle Closure
Risk Factors
Race and Ethnicity
The prevalence of PACG in patients older than 40 years varies greatly, depending on race and ethnicity; for example, it is 0.1%–0.6% in people of African ancestry, 0.1%–0.4% in European-derived populations, 0.3%–2.2% in Japanese individuals, 0.4%–1.7% in Chinese individuals, and 2.1%–4.8% in Inuit persons. Some of this variation in prevalence—for example, between white individuals and Inuit individuals—can be explained by differences in the biometric parameters (anterior chamber depth, axial length) of these groups; however, the increased prevalence of PACG in Chinese and in other East Asian populations cannot be explained by major biometric parameters alone. Recent anterior segment anatomic studies suggest that differences in other parameters such as iris thickness and area; dynamic changes in the iris; lens vault; and anterior chamber width can be significant contributing factors. It has become increasingly clear that the burden of PACG is greater in Asian countries. However, recent increases in the prevalence of myopia (with associated axial elongation) in Asian countries—particularly urban areas—may counterbalance these trends in PACG.
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Day AC, Baio G, Gazzard G, et al. The prevalence of primary angle closure glaucoma in European derived populations: a systematic review. Br J Ophthalmol. 2012;96(9):1162–1167.
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Quigley HA. Angle-closure glaucoma—simpler answers to complex mechanisms: LXVI Edward Jackson Memorial Lecture. Am J Ophthalmol. 2009;148(5):657–669.
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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 systemic review and meta-analysis. Ophthalmology. 2014;121(11):2081–2090.
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.