Distribution of ocular perfusion pressure and its relationship with open-angle glaucoma: The singapore malay eye study

Purpose. To describe the distribution of ocular perfusion pressure and its relationship with open-angle glaucoma (OAG) in a Malay population. Methods. This was a population-based, cross-sectional study comprising 3280 (78.7% response) ethnic Malays. Intraocular pressure (IOP) was measured with Goldmann applanation tonometry. Systolic and diastolic blood pressure (SBP and DBP) was measured with a digital automatic blood pressure monitor. Mean ocular perfusion pressure (MOPP) = 2/3(mean arterial pressure - IOP), where mean arterial pressure (MAP) = DBP + 1/3(SBP - DBP), systolic perfusion pressure (SPP) = SBP - IOP, and diastolic perfusion pressure (DPP) = DBP - IOP, was calculated. The diagnosis of OAG was based on International Society for Geographical and Epidemiologic Ophthalmology criteria. Results. A total of 3261 persons (mean age, 58.7 ±11 years, including 131 [4.0%] cases of OAG) were available for analyses. Among persons without glaucoma, the mean ± SD IOP, MOPP, SPP, and DPP were 15.3 ± 35, 52.8 ± 93, 1315 ± 23.3, and 64.5 ± 11.3 mm Hg, respectively. Among persons with OAG, the corresponding values were 16.8 ± 5.9, 51.6 ± 10.2, 134.5 ± 24.6, and 61.4 ± 11.5 mm Hg, respectively. In multiple logistic regression models adjusting for IOP, age, sex, and IOP- and BP-lowering treatments, OAG risk was significantly higher in participants with DBP, MOPP, or DPP in the lowest quartile (Q1) than in participants in the highest quartile (Q4) (Q1 vs. Q4: odds ratio [OR], 1.71 [95% confidence interval (CI), 1.04-2.96] for DBP; OR, 1.73 [95% CI, 1.05-3.15] for MOPP; OR, 1.75 [95% CI, 1.02-3.01] for DPP). Conclusions. Low DBP, low MOPP, and low DPP are independent risk factors for OAG in ethnic Malays, providing further evidence of a vascular mechanism in glaucoma pathogenesis across different populations.