Longitudinal visual field and quality of life change in the Treatment for Advanced Glaucoma Study.

Abstract

Progressive visual field (VF) loss from glaucoma affects patients' quality of life (QoL). While treatments aim to preserve vision, the extent to which slowing VF loss translates into QoL changes in advanced disease is not fully understood. We compare the 5-year rate of VF and QoL change and examine their correlation in the Treatment for Advanced Glaucoma Study (TAGS). multicenter randomized clinical trial (27 secondary care glaucoma departments in the United Kingdom). 453 adults with newly diagnosed advanced open-angle glaucoma in at least one eye, consecutively recruited between June 3, 2014, and May 31, 2017, were randomized to trabeculectomy (227) or medical management (226) as initial treatment. One eligible index-eye was identified per participant MAIN OUTCOME MEASURES: the mean difference in rate of change in monocular index-eye VF (24-2 SITA Standard), binocular integrated VF (BI-VF), and the 25-item Visual Function Questionnaire (VFQ-25) composite score over 5 years (intention-to-treat) using a validated Bayesian longitudinal hierarchical model. Data from 442 patients with reliable VF (false positive <15%) or VFQ-25 data from ≥2 time points were included (221 in the trabeculectomy-first arm). Baseline characteristics were similar between arms. The rate of index-eye VF loss was faster in the medications-first arm (-0.75 [-0.90, -0.59] dB/year, Estimate [95%-Credible Intervals]) compared to the trabeculectomy-first arm (-0.37 [-0.53, -0.22] dB/year, p = 0.002). Differences between groups were not statistically significant for BI-VF decline (p = 0.062) or VFQ-25 change (p = 0.392). Correlations between VF and QoL were stronger for BI-VF for both baseline (0.41 [0.32, 0.49], p<0.001) and rate of change (0.56 [0.41, 0.70], p<0.001) than for index-eye VF (0.22 [0.12, 0.32], p<0.001 and 0.43 [0.26, 0.58], p<0.001, respectively). trabeculectomy more effectively reduced the rate of VF loss compared to medical treatment, in advanced glaucoma. Despite a moderately strong correlation with the BI-VF, there was no difference in the measured QoL, suggesting that the VFQ-25 might not be reactive or sensitive enough to monocular glaucoma interventions.