Predictive factors for open-angle glaucoma among patients with ocular hypertension in the European Glaucoma Prevention Study

Objective: To evaluate the predictive factors of open-angle glaucoma (OAG) in patients affected by ocular hypertension enrolled in the European Glaucoma Prevention Study (EGPS). Design: Randomized, double-masked, controlled clinical trial. Participants: One thousand seventy-seven patients, >= 30 years old, were enrolled at 18 European centers. The patients met inclusion criteria: intraocular pressure, 22 to 29 mmHg; 2 normal and reliable visual fields (VFs) (on the basis of mean deviation and corrected pattern standard deviation [PSD]); and a normal optic disc, as determined by an optic disc reading center. Intervention: Treatment with dorzolamide or a placebo (the vehicle of dorzolamide) in one or both eyes. Main Outcome Measures: Efficacy end points were VF and/or optic disc changes. Baseline demographic and clinical data were collected before randomization, except for corneal thickness measurements, which were determined during follow-up. Proportional hazards models were used to identify factors that predicted which participants in the EGPS had developed OAG. Results: In multivariate analyses, factors that predicted the development of OAG included older age (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.04-1.69), larger vertical cup-to-disc (C/D) ratio (HR, 1.34; 95% Cl, 1.14-1.58), larger vertical C/D ratio asymmetry (HR, 1.46; 95% Cl, 1.11-1.93), higher PSD (HR, 1.66; 95% Cl, 1.15-2.38), and lesser central corneal thickness (HR, 1.32; 95% Cl, 1.05-1.67). Conclusions: Baseline age, vertical C/D ratio, vertical C/D ratio asymmetry, and PSD were good predictors of the onset of OAG in the EGPS. Central corneal thickness was found to be a powerful predictor of the development of OAG. The EGPS results agree with the findings of the Ocular Hypertension Treatment Study and support the need for a thorough evaluation of patients with ocular hypertension.