Pseudoexfoliation as a risk factor for prevalent open-angle glaucoma

Purpose: To estimate the risk of open-angle glaucoma (OAG) associated with exposure to pseudoexfoliation (PEX) and increased intraocular pressure (IOP). Methods: In 1984-86, a cross-sectional, population-based survey was conducted in the municipality of Tierp, central Sweden. Its target population comprised 2429 residents aged 65-74 years. In addition to a sample of 760 people, patients previously diagnosed with glaucoma were examined. The prevalence of OAG in the target population was estimated from the prevalence in the sample and patients already diagnosed. A review of prevalent cases in 1984-86 was undertaken in 2006. Results: Definite OAG was established in 77 cases, corresponding to a prevalence of 5.3% (95% confidence interval [CI] 4.4-6.2). Of these, 23 represented newly detected cases. The prevalence of PEX was 17.2% (95% CI 14.6-19.9), calculated from 134 cases in the population sample. When adjusting for gender, PEX was associated with a 4.7-fold (95% CI 2.2-9.4) increased risk of OAG. For clinical cases only, the risk was 16-fold (95% CI 4.8-56) greater in subjects with PEX, compared with those without PEX. In individuals without a previous diagnosis of glaucoma, an IOP >= 20 mmHg was associated with a 9.7-fold (95% CI 3.7-27) increased risk, but PEX alone was not a risk factor for OAG (adjusted odds ratio = 0.96). Conclusions: Pseudoexfoliation was associated with OAG only in people previously diagnosed with the disease. In cases detected in the population-based survey, increased IOP was a serious risk factor.