Laser Suture Lysis after Mitomycm C Trabeculectomy

Abstract

To evaluate the timing, efficacy, and complications of laser suture lysis (LSL) after mitomycin C trabeculectomy in patients with glaucoma at high risk for failure of filtering surgery. The authors retrospectively reviewed the charts of 62 consecutive patients who underwent a total of 66 sessions of LSL after trabeculectomy with mitomycin C. The interval from surgery to LSL ranged from 2 to 65 days (mean +/- standard deviation, 17.9 +/- 14.9 days). The average intraocular pressure (IOP) reduction after LSL was 11.9 +/- 8.9 mmHg (range, 3-40 mmHg). A longer interval to LSL was correlated with a lesser degree of pressure reduction (P=0.0004, Wilcoxon rank-sum test). After LSL, hypotony developed in 13 (21%) patients (IOP < 6 mmHg on 2 consecutive measurements at least 24 hours apart). This resolved spontaneously after 7 to 304 days (104.1 +/- 109.1 days) in 12 (92%) of the 13 patients. Life-table success rates (success defined as 6 mmHg </= final IOP </= 21 mmHg) for the hypotony and no hypotony groups were 100% and 86% (at 6 months) and 96% and 86% (at 12 months), respectively. The final visual acuity worsened in a significantly greater percentage of patients in the hypotony group (46%) compared with the no-hypotony group (18%) (P = 0.06), Fisher's exact test). Laser suture lysis is safe and effective in augmenting aqueous filtration after mitomycin C trabeculectomy. A longer time interval between surgery and LSL may result in both a lesser degree of IOP reduction and a lower incidence of subsequent hypotony.