Relationship between systemic hypertension, perfusion pressure and glaucoma: a comparative study in an adult Indian...

To study the relationship between blood pressure (BP), intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) and primary open angle glaucoma (POAG) in patients with hypertension and compare it to a control group of normotensives.

Cross-sectional observational study.

A total of 108 subjects with primary hypertension and 100 age-matched controls without hypertension were enrolled for the study. IOP measurement using Noncontact Tonometer and dilated fundus evaluation using + 90 D lens were done for all cases. Single recording of BP was taken. Gonioscopy, Humphrey's central visual fields, optical coherence tomography and pachymetry were done for all subjects with IOP > 21 mm Hg or C: D ratio ≥ 0.5 or asymmetry of > 0.2.

Univariate and multivariate multinomial regression models were used to determine the association between covariates and risk of glaucoma or glaucoma suspect.

There was no difference in the glaucoma status between subjects with and without hypertension. Subjects on antihypertensive medications were 1΍ times more likely to have suspicious glaucoma (odds ratio [OR] =1.56] and nearly twice as likely to have POAG (OR = 1.85). In addition, we found a 31% and 12% reduction in risk of having POAG (95% confidence interval [CI] =13-45%, P = 0.001) and glaucoma suspect (95% CI = 2-21%, P = 0.03) respectively with every 1 mm Hg increment in MOPP.

Subjects on antihypertensive medications are more likely to have either glaucoma or glaucoma suspect, and higher ocular perfusion pressure offers relative protection from glaucomatous damage.