Quality of Life in the Tube Versus Trabeculectomy Study

Purpose To report the vision-specific quality-of-life (QoL) outcomes in the Tube Versus Trabeculectomy (TVT) Study. Design Multicenter randomized clinical trial. Methods SETTING: Seventeen clinical centers. STUDY POPULATION: Patients 18–85 years of age with medically uncontrolled glaucoma who had previous cataract and/or glaucoma surgery. INTERVENTIONS: Tube shunt (350-mm² Baerveldt glaucoma implant) or trabeculectomy with MMC. MAIN OUTCOME MEASURES: Vision-specific QoL using the NEI VFQ-25 and estimation of minimally important differences (MID) were the main outcome measures. Cross-sectional distribution- and anchor-based approaches were used to estimate MID. Clinical anchor measures included the mean deviation (MD) and logMAR visual acuity (VA) measurements. Clinically significant changes in anchor were defined as ≥2 dB MD and ≥0.2 logMAR. Results No significant differences in composite scores were observed between treatment groups, and no significant change in scores were seen over time. Mean (SD; range) values of clinical anchors at baseline were −16.6 (9.3; −32 to −0.5) dB for the surgical eye and 0.2 (0.3; −0.1 to 1.3) logMAR VA in the better-vision eye. For anchor-based cross-sectional analysis, composite score MID (95% CI) was 6.3 (4.6–7.9) for better-eye VA and 1.4 (0.9–1.9) for surgical eye MD. Distribution-based MID for the composite score was 6.0. Conclusions Trabeculectomy and tube shunt surgery had similar impact on patient-reported vision-specific QoL measured using the NEI VFQ-25. In this cohort of patients with advanced glaucoma, MIDs varied depending on the clinical anchor used. Distribution-based MIDs corresponded well with anchor-based MIDs based on VA measures. The MID values reported here may be useful for others wishing to interpret NEI VFQ-25 scores in their advanced glaucoma patient cohort.