The relationship between glaucoma and pseudoexfoliation: the Blue Mountains Eye Study

Abstract

Objective: To quantify the relationship between pseudoexfoliation (PXF) and open-angle glaucoma, ocular hypertension, and intraocular pressure (IOP) in a defined older population.

Methods: A cross-sectional study of 3654 people aged 49 to 97 years identified subjects with PXF during slitlamp examination. The IOP was measured by applanation tonometry. Glaucoma was diagnosed from characteristic visual field loss combined with optic disc cupping and rim thinning, without reference to IOP. Ocular hypertension was diagnosed if IOP was greater than 21 mm Hg in either eye, without field and disc changes. General estimating equation models were used to assess associations between eyes with PXF and glaucoma or ocular hypertension.

Results: Pseudoexfoliation was diagnosed in 2.3% of subjects, and both prevalence and bilaterality increased with age. Glaucomatous damage was present in 14.2% of eyes with PXF compared with 1.7% of eyes without PXF (age- and sex-adjusted odds ratio (OR), 5.0; 95% confidence interval (CI), 2.6-9.6). This was almost unchanged (OR, 4.8) after adjustment for glaucoma risk factors and was also relatively unaffected by IOP adjustment (OR, 3.7; 95% CI, 1.8-7.6). For subjects with PXF, the relationship with glaucoma persisted, but was weaker (OR, 2.3; 95% CI, 1.0-5.0) in the multivariate model. However, the population attributable risk from PXF was only 2.7%. Ocular hypertension was also more frequent in eyes with PXF (9.3%) than in eyes without PXF (3.1%) but was of borderline significance in the multivariate model (OR, 2.3; 95% CI, 0.9-5.7).

Conclusions: This study confirmed the strong relationship between glaucoma and PXF. Subjects with PXF had an increased risk of glaucoma, while eyes with PXF had a higher risk, which was independent of other glaucoma risk factors, including IOP.