The tube versus trabeculectomy study: design and baseline characteristics of study patients

Abstract

Purpose: The Tube Versus Trabeculectomy (TVT) Study will compare the safety and efficacy of nonvalved tube shunt surgery to trabeculectomy with mitomycin C in patients with previous intraocular surgery.

Design: Multicenter randomized clinical trial.

Setting: 17 Clinical Centers.

Study population: Patients 18 to 85 years of age who have undergone previous trabeculectomy, cataract extraction with intraocular lens implantation, or both and have inadequately controlled glaucoma with intraocular pressure (IOP) >or=18 mm Hg and <or=40 mm Hg on tolerated medical therapy.

Interventions: Study patients were randomized to undergo placement of a 350-mm(2) Baerveldt glaucoma implant or trabeculectomy with mitomycin C (0.4 mg/ml for 4 minutes).

Main outcome measures: IOP, complication rates, visual acuity, visual field, quality of life, reoperations for glaucoma, and need for supplemental medical therapy.

Results: A total of 212 patients were enrolled between October 1999 and April 2004. The age of the study population was 71.0 +/- 10.4 years (mean +/- SD), and 53% were women. The baseline IOP was 25.3 +/- 5.3 mm Hg (mean +/- SD). There were no significant differences in the demographic and ocular characteristics between the 2 treatment groups.

Conclusions: Practice patterns vary in the surgical management of glaucoma, and there are differing opinions among glaucoma surgeons regarding the preferred surgical approach in patients who have undergone previous cataract extraction and/or failed filtering surgery. Forthcoming data from the TVT Study should provide valuable information comparing two surgical procedures commonly used in this patient population.