Comparison of the safety and efficacy of Mitomycin C 0.02% used intra-operatively by subconjunctival injection versus direct scleral application using sponges in phacotrabeculectomy: A prospective randomized controlled trial

Abstract

Purpose: To compare the safety and efficacy of subconjunctival injection (MMC: 0.02%) to those with subconjunctival application of sponges soaked in Mitomycin C (MMC: 0.02%) intra-operatively in patients who underwent phacotrabeculectomy. Methods: A total of 68 patients undergoing phacotrabeculectomy were randomized into two groups; the sponge group received 0.02% MMC-soaked sponges (n = 38), and the injection group received subconjunctival injection of 0.02% MMC (n = 30). The primary outcome was post-operative mean intra-ocular pressure reduction (IOP). The secondary outcomes were bleb morphology using Indiana Bleb Appearance Grading Score (IBAGS) and anterior segment optical coherence tomography (AS-OCT), post-operative use of 5-fluorouracil, and complications rates. These were compared at 1 week and 1, 3, and 6 months post-operatively. Complete success was defined as ≥30% reduction in IOP without anti-glaucoma medications. Results: In sponge and injection groups, the mean pre-operative IOP was 29.1 ± 8.1 and 29.8 ± 8.8 mmHg, respectively. At 6 months, IOP in sponge and injection groups reduced by 52% (14 ± 3.6 mmHg, P < 0.001) and 50% (15.2 ± 4.1 mmHg, P < 0.001), respectively. Complete success was observed in 90.9% in the sponge group and 95.83% in the injection group. Both groups had diffuse, shallow, relatively avascular blebs at 6 months using IBAGS and AS-OCT. A few complications were seen in the sponge group during this period, which were not vision-threatening. Conclusion: Subconjunctival MMC injection is an effective, safe, convenient, and time-saving alternative to sponge-soaked delivery of MMC in phacotrabeculectomy.