PURPOSE: To evaluate the effectiveness of a hydrogel sealant versus a suture in preventing fluid egress after wound leakage in cataract surgery. SETTING: Twenty-four ophthalmic clinical practices in the United States. DESIGN: Prospective randomized parallel-arm controlled multicenter subject-masked study. METHODS: Healthy patients having uneventful clear corneal incision (CCI) cataract surgery were eligible for the study. Spontaneous and provoked fluid egress from wounds was evaluated at the time of surgery using a calibrated force gauge. Eyes with leakage were randomized to receive a hydrogel sealant (Resure) or a nylon suture at the main incision site. Incision leakage was reevaluated 1, 3, 7, and 28 days postoperatively. RESULTS: Of 500 eyes, 488 had leakage at the time of cataract surgery. The leak was spontaneous in 244 cases (48.8%), and 488 (97.6%) of all incisions leaked with 1.0 ounce or less of applied force. After randomization, 12 (4.1%) of 295 eyes in the sealant group and 60 (34.1%) of 176 eyes in the suture group had wound leakage with provocation (P<.0001). The overall incidence of adverse ocular events was statistically significantly lower in the sealant group than in the suture group (P<.05). CONCLUSIONS: In this study, 97.6% of CCIs leaked after cataract surgery. The hydrogel sealant was safe and effective and better than a suture for the intraoperative management of CCIs with leakage as seen on Seidel testing and for the prevention of postoperative fluid egress.