Two-Year Visual Field Outcomes of the Treatment of Advanced Glaucoma Study (TAGS)

Abstract

to compare visual field (VF) progression between the 2 arms of the Treatment of Advanced Glaucoma Study (TAGS). Post hoc analysis of VF data from a 2-arm, multicenter, randomized controlled clinical trial. A total of 453 patients with newly diagnosed advanced open-angle glaucoma in at least 1 eye from 27 centers in the United Kingdom were randomized to either trabeculectomy (n=227) or medication in their index eye (n=226) and followed-up for 2 years with 2 24-2 VF tests at baseline, 4, 12, and 24 months. Data were analyzed for participants with a reliable VF (false positive rate < 15%) at baseline and at least 2 other time points. Average difference in rate of progression (RoP) was analyzed using a hierarchical Bayesian model. Time for each eye to progress from baseline beyond specific cut-offs (0.5, 1, 1.5, and 2 dB) was compared using survival analysis. This study analyzed 211 eyes in the trabeculectomy first arm and 203 eyes in the medication first arm. The average RoP (estimate [95% credible intervals]) was -0.59 [-0.88, -0.31] dB/year in the medication first arm and -0.40 [-0.67, -0.13] dB/year in the trabeculectomy first arm. The difference was not significant (Bayesian P-value=.353). More eyes progressed in the medication first arm, but this difference was not significant. There was no significant difference in the average RoP at 2 years.