Tube shunt surgery and trabeculectomy yielded similar reductions in IOP and adjunctive use of anti-glaucoma medication, but tube shunt surgery had a higher success rate than trabeculectomy, according to 5-year data from the Tube Versus Trabeculectomy study.
“Trabeculectomy has historically been preferred over tube shunt implantation, except in refractory glaucomas at high risk for filtration failure,” the study authors said. “However, concern about bleb-related complications has contributed to an expanded use of tube shunts as an alternative to trabeculectomy.”
The TVT study, a prospective mulicenter clinical trial, included 212 patients; 107 patients received tube shunts and 105 patients underwent trabeculectomy. Patient age ranged from 18 to 85 years. All patients had uncontrolled glaucoma and had previously undergone cataract extraction with IOL implantation and/or failed filtering surgery.
Patients were randomized to undergo placement of a 350 mm2 Baerveldt glaucoma implant or trabeculectomy with mitomycin C 0.04 mg/mL for 4 minutes.
Study results showed that IOP reduction from baseline was 10.2 mm Hg in the tube shunt group and 12.4 mm Hg in the trabeculectomy group. Both reductions were statistically significant (P < .001).
Mean number of anti-glaucoma medications was reduced by 1.8 in the tube shunt group and 1.7 in the trabeculectomy group (both P < .001).
The tube shunt group had a 29.8% cumulative probability of failure during 5-year follow-up; the trabeculectomy group had a 46.9% cumulative probability of failure. The between-group difference was statistically significant (P = .002).
The reoperation rate for glaucoma was 9% in the tube shunt group and 29% in the trabeculectomy group (P = .025), the authors said.