Comparison of outcomes of trabeculectomies using 0.4 mg/ml versus 0.2 mg/ml concentrations of mitomycin-C

Abstract

Objectives: This study compared the outcomes of trabeculectomies using 0.2 mg/ml and 0.4 mg/ml mitomycin-C (MMC) and determined the factors that can predict the postoperative intraocular pressure (IOP).

Methods: A prospective, randomized, comparative study was performed involving patients undergoing trabeculectomy who were randomly assigned to either 0.2 mg/ml MMC for 4 minutes or 0.4 mg/ml for 2 minutes. The IOP, bleb characteristics, and occurrence of complications were compared. Age and gender of the patients, preoperative IOP, MMC concentration, bleb characteristics, angle status, and age of the surgery were analyzed to determine if they are predictive factors of the postoperative IOP using univariate and multivariate analyses.

Results: Seventy-four eyes of 68 patients underwent trabeculectomy: 36 eyes were treated with 0.2 mg/ml MMC for 4 minutes and 38 eyes with 0.4 mg/ml MMC for 2 minutes. There was no statistically significant difference in the mean preoperative IOP and postoperative IOP, as well as in the mean percent change in IOP (p = 0.87) between the 2 groups. Univariate and multivariate analyses showed the preoperative IOP (p = 0.02) and the type of filtering bleb (cystic p < 0.001; diffuse p = 0.045) as predictive factors of postoperative IOP. Kaplan-Meier survival curves showed no significant difference between the 2 groups at an average follow-up of 20 weeks.

Conclusion: There is no significant difference in the outcomes of trabeculectomies using 0.2 mg/ml and 0.4 mg/ml MMC. Preoperative IOP and bleb characteristics are factors predictive of successful filtration surgery.