Three-year results from the Tube versus Trabeculectomy Study showed that tube-shunt surgery was more likely than trabeculectomy with mitomycin C to maintain IOP control and avoid persistent hypotony, loss of light perception vision, or re-operation for glaucoma. A highly significant difference between study arms was apparent in the cumulative probability of failure analysis.

The cumulative probability of failure was estimated at 15.1% in the tube group and 30.7% in the trabeculectomy group at three years. The three-year analysis showed that most patients in both groups failed because of inadequate pressure control.

The treatment benefit for tube-shunt surgery was observed despite the findings of no significant difference between study groups in mean IOP and the mean number of glaucoma medications used at the three-year time point.

Visual acuity results in both study groups showed a reduction over the three-year period, and Snellen and Early-Treatment Diabetic Retinopathy Study acuity were similar for both sets of patients.

Although the findings do not demonstrate clear superiority of one glaucoma operation over the other, it was suggested that the role of tube shunts be expanded.

Three-year results from the Tube versus Trabeculectomy Study showed that tube-shunt surgery was more likely than trabeculectomy with mitomycin C to maintain IOP control and avoid persistent hypotony, loss of light perception vision, or re-operation for glaucoma.