Treatment outcomes in the Tube Versus Trabeculectomy (TVT) study after five years of follow-up

Abstract

Purpose: To report 5-year treatment outcomes in the Tube Versus Trabeculectomy (TVT) Study.

Design: Multicenter randomized clinical trial.

Settings: Seventeen clinical centers.

Study population: Patients 18 to 85 years of age who had previous trabeculectomy and/or cataract extraction with intraocular lens implantation and uncontrolled glaucoma with intraocular pressure (IOP) ≥18 mm Hg and ≤40 mm Hg on maximum tolerated medical therapy.

Interventions: Tube shunt (350-mm(2) Baerveldt glaucoma implant) or trabeculectomy with mitomycin C ([MMC]; 0.4 mg/mL for 4 minutes).

Main outcome measures: IOP, visual acuity, use of supplemental medical therapy, and failure (IOP >21 mm Hg or not reduced by 20%, IOP ≤5 mm Hg, reoperation for glaucoma, or loss of light perception vision).

Results: A total of 212 eyes of 212 patients were enrolled, including 107 in the tube group and 105 in the trabeculectomy group. At 5 years, IOP (mean ± SD) was 14.4 ± 6.9 mm Hg in the tube group and 12.6 ± 5.9 mm Hg in the trabeculectomy group (P = .12). The number of glaucoma medications (mean ± SD) was 1.4 ± 1.3 in the tube group and 1.2 ± 1.5 in the trabeculectomy group (P = .23). The cumulative probability of failure during 5 years of follow-up was 29.8% in the tube group and 46.9% in the trabeculectomy group (P = .002; hazard ratio = 2.15; 95% confidence interval = 1.30 to 3.56). The rate of reoperation for glaucoma was 9% in the tube group and 29% in the trabeculectomy group (P = .025).

Conclusions: Tube shunt surgery had a higher success rate compared to trabeculectomy with MMC during 5 years of follow-up in the TVT Study. Both procedures were associated with similar IOP reduction and use of supplemental medical therapy at 5 years. Additional glaucoma surgery was needed more frequently after trabeculectomy with MMC than tube shunt placement.

Trial registration: ClinicalTrials.gov NCT00306852.

Figure 1

Flowchart of patient progress in the Tube Versus Trabeculectomy Study.

Figure 2

Intraocular pressure (IOP) at baseline and follow-up in the Tube Versus Trabeculectomy Study. Data are presented as mean ± standard error of the mean and are censored after a reoperation for glaucoma.

Figure 3

Kaplan-Meier plots of the probability of failure in the Tube Versus Trabeculectomy Study.

Figure 4

Kaplan-Meier plots of the cumulative probability of failure in the Tube Versus Trabeculectomy Study defining inadequate intraocular (IOP) reduction as IOP > 17 mm Hg or not reduced by 20% below baseline (left) or IOP > 14 mm Hg (right). Inadequate IOP reduction criteria must have been present on 2 consecutive visits after 3 months to qualify as failure. Patients with persistent hypotony, reoperation for glaucoma, and loss of light perception vision are classified as failures.

Figure 5

Distribution of change in visual acuity from baseline to the 5-year follow-up visit in the Tube Versus Trabeculectomy Study.