Surgical outcomes of repeat trabeculectomy augmented with high dose mitomycin C

Purpose: To evaluate the surgical outcomes of repeat trabeculectomy augmented with risk factor adjusted mitomycin C (MMC) exposure in eyes with previous failed trabeculectomy. Methods: Case records of 38 eyes of 37 patients with previous failed filter who underwent repeat trabeculectomy with MMC were reviewed retrospectively. Main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP) reduction, requirement of anti-glaucoma medications, postoperative complications, and surgical success (defined as IOP of <= 21 mmHg and >5 mmHg along with 20% reduction from preoperative IOP with or without adjuvant medications) at 1-year postoperatively. Statistical analysis was done using the STATA 14.1 (Texas, USA). Results: Patient's mean age was 46.41 (+/- 20.43) years and the mean preoperative IOP was 32.73 (+/- 9.26) mmHg which reduced to 16.22 (+/- 7.08) mmHg postoperatively at 12 months (P < 0.001). Mean number of anti-glaucoma medications reduced from 2.76 (+/- 0.83) preoperatively to 1.89 (+/- 0.95) postoperatively (P < 0.001). Surgical success was observed in 81.1% at 1 year (n = 30). Eyes that received MMC >3 min had a postoperative mean IOP of 12.50 (+/- 3.23) mmHg compared to 23.08 (+/- 7.19) mmHg with MMC <3 min (P < 0.001). Seven eyes (18.4%) developed postoperative complications, and all were seen in eyes that received MMC >3 min (P = 0.033). Conclusion: Repeat trabeculectomy with MMC, used in higher concentration and exposure time altered according to individual risk factor plays a crucial role in the success and hence it could be considered as a viable option before planning a tube surgery.