Deep sclerectomy versus trabeculectomy with low-dosage mitomycin C: Four-year follow-up

Aims: To compare the long-term effects of low-dosage mitomycin C (MMC) in both deep sclerectomy (DSMMC) and trabeculectomy (TPMMC) on intraocular pressure (IOP). Methods: Analysis of extended follow-up of data from a prospective clinical trial. Forty patients were originally randomised to undergo either DSMMC (19 eyes) or TPMMC (21 eyes). Follow-up was performed at postoperative day 1, weeks 1, 2 and 3, as well as months 1, 3, 6, 9, 12, 18, 24, 36 and 48. Two- to three-week data were not included in the statistical analysis. Postoperative complications, number of anti-glaucoma medications and IOP were recorded at each visit. Complete (no medications) and qualified (with or without medications) successes were assessed at 2 target IOPs (<= 21 and <= 17 mm Hg) and evaluated by Kaplan-Meier curves. Results: At 48 months, the mean IOP (+/- SD) was 17.6 +/- 3.4 and 17.8 +/- 3.6 mm Hg in the DSMMC and TPMMC eyes, respectively, a significant reduction from preoperative IOP in each group (p < 0.0005). Complete success was achieved at the <= 21 mm Hg target IOP in 10 (52.6%) and 14 (66.6%) eyes and qualified success in 15 (78.9%) and 18 (85.7%) eyes in the DSMMC and TPMMC groups, respectively. There were no differences in the Kaplan-Meier curves. Hypotony and shallow anterior chamber were significantly more frequent in the TPMMC group. Conclusions: Either procedure controlled IOP efficaciously at our endpoint. Low-dosage MMC can be considered a mild enhancement of deep sclerectomy IOP-lowering effect. Copyright (c) 2008 S. Karger AG, Basel.