Open-angle glaucoma and systemic hypertension: the blue mountains eye study

Abstract

Purpose: To assess whether systemic hypertension is associated with open-angle glaucoma (OAG) in an older population.

Patients and methods: The Blue Mountains Eye Study examined 3654 subjects aged 49 to 97 years. Hypertension was diagnosed from history in treated subjects or from systolic blood pressure (BP) > or=160 mm Hg or diastolic BP > or=95 mm Hg. OAG was diagnosed from congruous glaucomatous optic disc rim thinning and visual field loss, without reference to intraocular pressure (IOP) level. Ocular hypertension (OH) was defined when IOP was > 21 mm Hg in either eye, among persons without OAG.

Results: Hypertension was present in 45.7% of subjects, OAG in 3.0%, and OH in 5.2%. Hypertension was significantly associated with OAG, after adjustment for OAG risk factors including IOP, odds ratio (OR) 1.56, 95% confidence interval (CI) 1.01-2.40. This relation was strongest in subjects with poorly controlled treated hypertension (OAG prevalence 5.4%), compared with normotensive subjects (OAG prevalence 1.9%), independent of IOP (OR 1.88, CI 1.09-3.25). The population attributable risk for hypertension (20.4%) was higher than for other identified OAG risk factors. The prevalence of OH was 8.1% in subjects with poorly controlled treated hypertension (OR 1.81, CI 1.20-2.73) and 8.2% in untreated hypertension (OR 1.96, CI 1.31-2.95), compared with 4.2% in normotensive subjects.

Conclusions: Hypertension, particularly if poorly controlled, appears related to a modest, increased risk of OAG, independent of the effect of BP on IOP and other glaucoma risk factors. However, we could not exclude nocturnal hypotensive episodes among treated subjects. Hypertension was also associated with OH, a relationship that could in part reflect the influence of BP on IOP.