Early postop complications more common with trabeculectomy than tubes

March 7, 2009

San Diego-In the Tube versus Trabeculectomy (TVT) Study, patients undergoing trabeculectomy with mitomycin C (MMC) were more likely to experience early postoperative complications than were those who had tube shunts implanted, but rates of late postoperative complications and serious complications associated with vision loss and/or re-treatment were similar for both surgical procedures, said Donald L. Budenz, MD, MPH, professor of ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine.

San Diego—In the Tube versus Trabeculectomy (TVT) Study, patients undergoing trabeculectomy with mitomycin C (MMC) were more likely to experience early postoperative complications than were those who had tube shunts implanted, but rates of late postoperative complications and serious complications associated with vision loss and/or re-treatment were similar for both surgical procedures, said Donald L. Budenz, MD, MPH, professor of ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine.

He reported on surgical complications seen in the TVT Study during the first 3 years of follow-up.

“There were a large number of surgical complications in the TVT Study, probably related to accurate reporting of complications in the TVT Study,” he said. “Most of the complications, however, were transient and they resolved on their own without intervention.”

The TVT Study is a prospective, multicenter, randomized clinical trial including patients aged 18 to 85 years who had previous trabeculectomy, cataract extraction with IOL implantation, or both, as well as uncontrolled glaucoma on maximum tolerated medical therapy, with IOP ranging from 18 to 40 mm Hg.

Early postoperative complications were defined as those occurring within the first month, and late postoperative complications were defined as those occurring after the first month. The number of patients with early postoperative complications included 22 (21%) in the tube group and 37 (35%) in the trabeculectomy group. More wound leaks were seen in the trabeculectomy group than in the tube group, Dr. Budenz said. Late postoperative complications developed in 30 (28%) patients in the tube group and 33 (31%) patients in the trabeculectomy group.

Twenty-four (22%) of patients in the tube group had surgical complications associated with a loss of more than two Snellen lines, compared with 28 (27%) of patients in the trabeculectomy group.

“There was no difference in the rate of vision loss following trabeculectomy with MMC or tube shunt surgery,” Dr. Budenz said. “Many causes of vision loss, we found, were unrelated to surgical intervention.”

Cataract progression was common and occurred with similar frequency with both surgical procedures, he said. It was observed in 14 (58%) phakic patients in the tube group and in 12 (57%) phakic patients in the trabeculectomy group.