Abstract
Purpose :
To identify factors associated with visual field (VF) deterioration in the United Kingdom Glaucoma Treatment Study (UKGTS).
Methods :
The UKGTS is the first randomised, double-masked, placebo-controlled, multicentre trial on the visual field (VF) preserving effect of medical treatment in open-angle glaucoma (OAG). Five hundred sixteen participants with previously untreated OAG were randomized to either latanoprost 0.005% or placebo. Eligibility criteria were modeled on those for the Early Manifest Glaucoma Trial. The observation period was 2 years, with subjects monitored by VF testing, among other procedures, at 11 visits. VF deterioration was based on the Guided Progression Analysis pattern deviation maps. Frailty models (extension of the Cox proportional model) were fitted to compute the hazard ratios (HRs) and respective 95% confidence intervals (CIs) for time to progression whilst accounting for the correlation within sites. Model selection was guided by backwards stepwise selection conducted on the model containing all variables which were significant at the 0.2 level in the univariable analysis.
Results :
Treatment with latanoprost reduced the HR for VF deterioration by 54% (HR, 0.46; 95% CI, 0.30-0.73, p=0.001). Progression factors were higher baseline mean intraocular pressure (HR, 1.05 per mmHg; 95% CI, 1.004-1.106, p=0.03) and disk haemorrhage at any visit (HR, 1.68; 95% CI, 1.09-2.60, p=0.02). Smoking (current or previous) was associated with reduced HR for VF deterioration (HR, 0.63; 95% CI, 0.41-0.98, p=0.04). No other factors were found to be statistically significant in the multivariable analysis.
Conclusions :
In the UKGTS, treatment with latanoprost halved progression risk. Previously reported progression factors for OAG were incorporated in the model, and only disc haemorrhage and baseline intraocular pressure were confirmed. The association of smoking history requires further exploration to assess for potential confounding.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.