Risk Factors for Open-Angle Glaucoma in a Japanese Population : The Tajimi Study

PurposeTo identify the risk factors associated with primary open-angle glaucoma (POAG) in the Tajimi Study.DesignPopulation-based cross-sectional epidemiologic study.ParticipantsOne hundred nineteen POAG patients and 2755 controls.MethodsUnivariate and multivariate comparison of ocular factors and systemic factors between POAG patients and controls.Main Outcome MeasuresDifference in factors between POAG patients and controls, factors associated with POAG patients, and their odds ratio (OR).ResultsIntraocular pressure (IOP), age, myopia, and history of hypertension differed between POAG patients and controls in univariate analyses. Multivariate analysis with logistic regression with stepwise selection of variables demonstrated that higher IOP (OR, 1.12 [95% confidence interval (CI), 1.04–1.21]), myopia (ORs, 1.85 [95% CI, 1.03–3.31] for low myopia and 2.60 [95% CI, 1.56–4.35] for moderate to high myopia), and older age (OR, 1.06 [95% CI, 1.04–1.08]) were associated with an increased risk of having POAG.ConclusionsAlthough the majority (92%) of POAG patients diagnosed in the Tajimi Study had IOP within the normal range, IOP was still identified as a significant risk factor for POAG. Together with IOP, myopia and age were significant risk factors for having POAG.