Comparison of Methods to Deliver Mitomycin C in Trabeculectomy Surgery

Topic: Compare different methods to deliver mitomycin C (MMC) in trabeculectomy surgery. Clinical Relevance: Knowing the best way to apply MMC may provide guidance to glaucoma surgeons and improve outcomes. Methods: Systematic review and meta-analysis (PROSPERO CRD42023394371) for studies comparing ≥ 2 methods to apply MMC in trabeculectomy published until February 22, 2023, from Medline, EMBASE, and CENTRAL. Randomized clinical trials (RCTs), quasi-randomized, and prospective nonrandomized controlled studies published in English and conducted on human subjects were included. The primary outcome was surgical failure at 1 year. Secondary outcomes included intraocular pressure (IOP), number of glaucoma medications, postoperative complications, and interventions. A random-effects meta-analysis was conducted for ≥ 3 studies, whereas a fixed-effect model was used for 2 studies. The certainty of evidence was assessed with Grading Recommendations Assessment, Development and Evaluation (GRADE) score. Results: From 7899 records, 8 articles from 7 RCTs compared intraoperative sub-Tenon MMC injection (315 participants) and intraoperative MMC-soaked sponges (327 participants). One RCT and 1 quasi-randomized study compared postoperative (60 participants) and intraoperative (60 participants) MMC-soaked sponge application. In the injection vs. sponges comparison, no significant difference in surgical failure (relative risk [RR]: 0.78, 95% confidence interval [CI]: 0.48–1.28; P = 0.33, GRADE score moderate) or IOP (mean difference [MD]: −0.85 mmHg, 95% CI: −2.19 to 0.49; P = 0.21, GRADE score moderate) was found at 1 year. Sub-Tenon injection resulted in fewer postoperative medications (MD: −0.40, 95% CI: −0.63 to −0.18; P < 0.001; GRADE score moderate) and better bleb morphology (GRADE score high) in terms of height (MD: −0.39, 95% CI: −0.61 to −0.18; P < 0.001), extension (MD: 0.28, 95% CI: 0.11–0.45; P = 0.001), and vascularity (MD: −0.52, 95% CI: −0.72, −0.31; P < 0.001) than sponges. Serious complication and reintervention rates were low and comparable between groups. We did not perform a meta-analysis comparing postoperative and intraoperative sponge application because of heterogeneity in the study designs of the included studies. Conclusions: Intraoperative sub-Tenon MMC injection is noninferior to intraoperative MMC-soaked sponges in trabeculectomy surgery in terms of surgical failure and IOP control, with a reduced number of medications, improved bleb morphology, and similar safety profile. Further research with a long-term follow-up is necessary to confirm their long-term equivalence. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.