Short-term outcomes of Mitomycin-C augmented phaco-trabeculectomy using subconjunctival injections versus soaked sponges: a randomized controlled trial

Objectives To determine whether subconjunctival Mitomycin-C (MMC) injections are as safe and effective as sponge-soaked MMC in phaco-trabeculectomy. Methods This prospective, randomized, interventional study was conducted on consecutive patients with visually significant cataract and an uncontrolled primary open-angle glaucoma. One hundred thirty-nine patients were recruited but 15 were ineligible for analysis. The patients were randomized into a sponge/injection group. All participants received a twin-site phaco-trabeculectomy. They were followed up on days 1, 15, 30, 3 months and 6 months post-operatively. A p-value < 0.05 was considered significant. Interventions Participants in the sponge group received an augmentation of their phaco-trabeculectomy with sponges soaked in a mixture of 0.04% MMC and 2% preservative-free Lignocaine in a 1:1 ratio, placed in the subconjunctival space for four minutes. Participants in the injection group received the same mixture as a subconjunctival injection, after surgical draping. Results There were 62 patients in each group. The groups had no significant differences in their baseline characteristics. The mean IOP at 6 months was significantly lower in the injection group (14.8 +/- 3.7 mm Hg) than in the sponge group (17.1 +/- 6.4 mm Hg) (p = 0.02). There was no notable difference in the complications or the final post-operative visual outcome but a significantly greater number of patients in the sponge arm required removal of the releasable suture (p = 0.001) and additional anti-glaucoma medications (p = 0.04) at six months post-operatively. Conclusions Subconjunctival MMC achieves a lower IOP with fewer anti-glaucoma medications than sponge-soaked MMC at six months for twin-site phaco-trabeculectomy in primary open-angle glaucoma with no additional risks.