Objective To elucidate the inter-relationship between ocular perfusion pressure (OPP), blood pressure (BP), intraocular pressure (IOP) profiles and primary open-angle glaucoma (POAG) in a multiethnic Asian population.

Methods Participants were recruited from the Singapore Epidemiology of Eye Diseases Study and underwent standardised ocular and systemic examinations. POAG was defined according to the International Society for Geographical and Epidemiological Ophthalmology criteria. Logistic regression analyses with generalised estimating equation models were performed and used to account for correlation between eyes.

Results A total of 9877 participants (19 587 eyes), including 213 POAG cases (293 eyes) were included. Eyes with lowest quartile levels of systolic OPP (SOPP <110 mm Hg) were 1.85 times (95% CI 1.16 to 2.95) likely to have POAG, compared with eyes with mid-range SOPP levels (123–137 mm Hg; third quartile), after adjusting for relevant covariates and IOP. Consistently, we found that lowest quartile of systolic BP (SBP <124 mm Hg) was 1.69 times (95% CI 1.08 to 2.66) likely to have POAG, compared with mid-range SBP levels (138–153 mm Hg; third quartile). Furthermore, the effect of lower SBP on POAG was more pronounced in eyes with IOP ≥21 mm Hg (OR 3.90; 95% CI 1.24 to 12.30). Both the mean and diastolic profiles of OPP and BP were not significantly associated with POAG, after adjusting for relevant covariates and IOP.

Conclusions In this population-based sample of nearly 10 000 Asian individuals, we showed that low SOPP was associated with POAG. This association was potentially in part secondary to low SBP and high IOP. Our findings provide further clarity on the roles of OPP surrogates and BP profiles in POAG.