Objective To evaluate the efficacy and tolerability of nonpenetrating glaucoma surgery augmented with mitomycin C (NPGSMMC) compared with trabeculectomy plus mitomycin C (TEMMC) in the treatment of patients with open angle glaucoma.
Methods  Pertinent studies were selected through extensive searches of the Cochrane Library, Medline, Embase, and meeting abstracts. Randomized clinical trials comparing NPGSMMC with TEMMC in patients with glaucoma were selected by predefined criteria. The main efficacy measures were weighted mean differences (WMDs) for the percentage intraocular pressure reduction (IOPR%), and relative risks (RRs) for the complete and qualified success rates. The main tolerability measures were RRs for adverse events. The pooled estimates were carried out in RevMan version 4.2 software according to a random effect model.
Results Eight studies enrolling a total of 459 eyes in patients with open angle glaucoma were included in the meta-analysis. NPGSMMC was associated with numerically smaller but nonsignificant percentage reduction in IOP compared with TEMMC, with a WMD for the IOPR% of -1.27% (95% confidence interval, -5.61 to 3.07) at 1 year, -4.55% (-10.35 to 1.24) at 2 years, -0.82% (-8.80 to 7.17) at 3 years, and -6.16% (-25.97 to 13.65) at 4 years. Significantly greater proportions of TEMMC patients than NPGSMMC patients achieved the target IOP without antiglaucoma medication at the end point, with a pooled RR of 0.74 (0.63 to 0.86). NPGSMMC was associated with a significantly lower frequency of shallow anterior chamber and cataract than TEMMC, with pooled RR of 0.31 (0.16 to 0.60) and 0.23 (0.11 to 0.47) respectively.
Conclusions  NPGSMMC was associated with comparable efficacy in lowering morning IOP than TEMMC. However, significantly fewer patients achieved the target IOP with NPGSMMC and than with TEMMC. NPGSMMC was better tolerated than TEMMC.