Authors: Nitin Anand, Vinod K Dawda
Purpose: To report the comparative efficacy and safety of intraoperative 5-fluorouracil (5-FU) or mitomycin C (MMC) in primary trabeculectomy in Nigeria. Materials and Methods: Retrospective chart review of patients undergoing primary antimetabolite trabeculectomy in Lagos, Nigeria between 1996 and 2003. We included 129 patients (132 eyes) of the 210 patients with greater than one year postoperative follow-up. Success rates between groups were compared by Kaplan-Meier survival analysis. IOP changes between groups were compared with ANOVA test. Non-parametric comparisons were performed with the Chi-square test with Yates correction or Fisher exact test. A P value less than 0.05 was considered statistically significant. Results: Seventy-three eyes underwent 5-FU (5-FU group) and 59 eyes underwent MMC augmentation (MMC group) during primary trabeculectomy. The 5-FU group had longer mean follow-up of 53 ± 26 months than the MMC group (38 ± 18 months, P<0.001). The preoperative intraocular pressure was 25.4 ± 6.2 in the MMC group and 25.8 ± 6.0 mm Hg in the 5FU group (P=0.8). Postoperative IOPs were significantly lower (P<0.05) in the MMC group at all follow up visits except between 30-35 months (P=0.07). The probability of maintaining an IOP less than 19 mmHg and 15 mmHg without additional medication or needle revisions at 2 and 3 years postoperatively was 71 (95% CIs, 54-82%) and 64% (95% CIs, 53-76%) respectively for the 5FU group and 81 (95% CIs,71-92%) and 79% (95% CIs,69-90%) respectively for the MMC group. The MMC group had significantly better survival times, both for IOP less than 19 mm Hg (P=0.03) and IOP less than 15 mm Hg (P= 0.006). At last follow up, 40 eyes (30.3%) had lost more than 2 lines of Snellen visual acuity, 24 from 5-FU and 16 from the MMC group (P=0.8). The MMC group was statistically less likely than the 5-FU group to require medications (18.5% vs. 41.1%, P =0.007) or needle revisions (5.1% vs. 17.8%, P=0.03) to control IOP. Blebitis and endophthalmitis developed in one eye each in both groups. Persistent hypotony was observed in 4 eyes (6.8%) in the MMC group only. Conclusions: In this study of Nigerian patients, intraoperative application of MMC was more efficacious than 5-FU in lowering IOP following primary trabeculectomy. However, delayed ocular hypotony was only seen with MMC use.