Comparison of Preoperative Subconjunctival Injection,Intraoperative Subconjunctival Injection,and Soaked Sponges as Mitomycin C Delivery Methods for Trabeculectomy with a 6-Month Follow-Up Period: A Randomized Controlled Pilot Study

Abstract

Purpose:

This study evaluated the efficacy and safety of 3 mitomycin C (MMC) delivery methods in trabeculectomy for uncontrolled primary open-angle glaucoma (POAG): preoperative subconjunctival injection, intraoperative subconjunctival injection, and conventional soaked sponges.

Methods:

In this randomized controlled pilot study, 25 patients were assigned to 3 groups: Group A received a preoperative subconjunctival injection of 0.1 mL MMC 0.002% 2 weeks before surgery; Group B received an intraoperative subconjunctival injection of 0.1 mL MMC 0.01%; and Group C received MMC 0.02% via soaked sponges during surgery. Patients were followed for 6 months. Primary outcome was surgical success—complete [intraocular pressure (IOP) 5–21 mm Hg with ≥30% reduction from baseline without medications] or qualified (with medications). Secondary outcomes included IOP, medication use, best-corrected visual acuity, and complications.

Results:

At 6 months, complete success rates were 75.0% (Group A), 66.7% (Group B), and 50.0% (Group C) (P = 0.54). Mean baseline IOP was 17.40 ± 4.43 mm Hg with 3.64 ± 0.70 medications. Postoperative IOPs were 9.88 ± 2.70, 10.67 ± 4.06, and 10.38 ± 5.04 mm Hg in Groups A, B, and C, respectively (P = 0.92). Medication use postoperatively was lowest in Group A (0 ± 0), compared to Groups B (0.7 ± 1.0) and C (0.4 ± 1.1) (P = 0.30). Visual outcomes and complication rates were similar across groups.

Conclusions:

In this pilot study, all MMC delivery methods demonstrated comparable success rates, IOP reduction, and safety outcomes. Subconjunctival MMC injections show promise as a viable alternative to the conventional sponge application. However, due to the small sample size, further larger-scale studies are warranted to validate these findings.