Mitomycin C Trabeculectomy for Uncomplicated Glaucoma: A Comparison between 0.25 and 0.5mg/ml of Mitomycin C

Lee, Sung Min; Uhm, Ki Bang

Abstract

The purpose of this study is to compare the efficacy and safety of 0.25 and 0.5mg/ml of mitomycin C(MMC) on the outcome of glaucoma filtration surgery in eyes undergoing primary trabeculectomy. Twenty-eight eyes of 20 patients with primary open-angle glaucoma or primary angle-closure glaucoma, who underwent primary trabeculectomy with 0.25mg/ml MMC for 3 minutes were compared with a demographically similar group of 31 eyes of 22 patients with primary open-angle glaucoma or primary angle-closure glaucoma, who had undergone primary trabeculectomy with 0.5mg/ml MMC for 3 minutes. MMC was applied between the sclera and Tenon's capsule during trabeculectomy, and scleral flap was closed with tight releasable sutures. The mean preoperative intraocular pressure was 35.2 +/- 9.3mmHg in the 0.25mg group and 32.1 +/- 9.2mmHg in the 0.5mg group(p=0.21, Student's unpaired t-test). The mean number of preoperative medications was 2.7 +/- 0.9 and 2.7 +/- 0.8(p=0.92, Mann Whitney U test), respectively. No statistically significant differences were found in mean intraocular pressures between the two groups at the three. six, and nine months postoperative periods. The mean follow-up was 9.2 months in the 0.25mg group and 9.0 months in the 0.5mg group(p=0.82, Student's unpaired t-test). At the last postoperative visit. 89%(25 eyes) in the 0.25mg group and 97%(30 eyes) in the 0.5mg group had an intraocular pressure less than 21mmHg with or without glaucoma medication(p=0.50, Fisher exact test). The mean intraocular pressures were 16.0 +/- 6.9mmHg and 13.6 +/- 3.6mmHg, respectively (p=0.10, Student's unpaired t-test). The 0.25mg group received an average of 0.5 medications for IOP control, and the 0.5mg group received an average of 0.2 medications(p=0.32, Mann Whitney U test). The postoperative visual outcome of the two groups did not differ significantly(p=0.27, Fisher exact test). There was no significant difference in complications between the two groups. Hypotony developed in one eye in the 0.5mg group. These results suggest that using 0.25 and 0.5mg/ml MMC for 3 minutes in primary trabeculectomy yields similar results in terms of efficacy and safety.