Management of hypotony after trabeculectomy with mitomycin C.

The purpose of this study was to determine the incidence and risk factors of hypotony and the effectiveness of medical and surgical treatment. A total 117 eyes of 103 patients that underwent trabeculectomy with mitimycin C (MMC) between 1993 and 2000 were reviewed. Hypotony was treated with the following methods in a stepwise manner: medical treatment, intrableb autologous blood injection, additional sutures to the scleral flap, necrotic bleb excision and advancement of the forniceal conjunctival flap. Hypotony developed in 30 eyes (25.6%) of 26 patients, among, which hypotonic maculopathy developed in 11 eyes (9.4%). The risk factors of hypotony were young age and primary open angle glaucoma. Because of no light sense, 6 of the 30 hypotonic eyes were not treated. Nineteen (79.2%) of the 24 treated hypotonic eyes were successfully managed. Five eyes, 3 with hypotony but maintaining visual acuity and 2 with follow-up loss, were not included in the success group. The mean intraocular pressure (IOP) before treatment, 2.5 +/- 1.2 mmHg, increased to 8.3 +/- 4.0 mmHg at 18.5 months follow-up. The stepwise treatment seems to be a useful method to manage hypotony after trabeculectomy with MMC.