The Effect of Adjunctive Mitomycin C on Outcomes of Phaco-Viscocanalostomy in Glaucoma: A Randomized Controlled Trial

PURPOSE: To evaluate whether adjunctive intraoperative mitomycin C (MMC) improves intraocular pressure (IOP) control, visual acuity, or medication burden in patients undergoing phaco-viscocanalostomy for moderate to advanced open-angle glaucoma. METHODS: This double-masked, parallel-group randomized clinical trial included 92 eyes of 92 patients with medically uncontrolled open-angle glaucoma, who were randomly assigned to undergo phaco-viscocanalostomy with (n = 46) or without (n = 46) adjunctive MMC (0.02% for 90 seconds). Outcomes including IOP, best-corrected visual acuity (BCVA), cup-to-disc ratio (C/D), and number of glaucoma medications were assessed at baseline, 1 week, and 1, 3, and 6 months postoperatively. RESULTS: After excluding 15 patients (9 lost to follow-up and 6 intraoperative rupture of the trabeculo-Descemet's window), 77 patients (36 in the MMC group and 41 in the control group) were included in the final analysis. No statistically significant differences were found between groups at baseline (all Ps > 0.14). Both groups showed significant IOP reduction at 6 months (mean IOP: 15.48 ± 2.63 mmHg in the MMC group versus 15.59 ± 3.32 mmHg in the control group; P = 0.88). BCVA improved significantly in both groups (P < 0.001), with no intergroup difference at 6 months (P = 0.84). The C/D ratio remained stable (P = 0.89). More than 80% of patients in both groups required no glaucoma medications at 6 months (P = 0.53). No significant time-by-group interaction was observed for any outcome (P > 0.05). CONCLUSION: The addition of MMC to phaco-viscocanalostomy did not provide statistically or clinically significant benefits in IOP control (clinically meaningful change defined as ≥ 2.5 mmHg IOP reduction), visual outcomes ( ≥ 0.1 logMAR change), or medication burden ( ≥ 1-medication reduction) over 6 months in patients with open-angle glaucoma. These findings do not support the routine addition of MMC to phaco-viscocanalostomy in uncomplicated open-angle glaucoma.