Two-stage intra-tenon injection versus sponge-applied mitomycin C-augmented trabeculectomy: a one-year study

Mitomycin C (MMC) is normally used to avoid scar formation in trabeculectomy. There has been a shift from conventional delivery via soaked sponges to preoperative injection of MMC. This study aimed to compare the effectiveness of a modified two-stage low-dose intra-Tenon injection with soaked sponges of MMC for trabeculectomy over a 1-year follow-up period.

This retrospective study enrolled patients with glaucoma undergoing modified trabeculectomy with a two-stage intra-Tenon injection (0.01%, 0.1 mL) or soaked sponges (0.02%) of MMC. In the former group, patients received intra-Tenon injection of MMC (the first stage) at least 4 h before trabeculectomy (the second stage). Patient characteristics, preoperative and postoperative intraocular pressure, antiglaucoma medication use, complications, and post-trabeculectomy surgical interventions were recorded during a 1-year follow-up period.

There were 36 and 35 eyes in the injection and sponge groups, respectively, in 58 patients. The injection group showed significantly lower intraocular pressure (p < 0.05) at every time point except on postoperative day 1 and week 1, fewer medications at the 1-year follow-up (p = 0.018), and a higher complete success rate (p = 0.011) than the sponge group. Both techniques showed a significant reduction in intraocular pressure and medication use at the 1-year follow-up. There were no significant differences in complications between both groups.

Our two-stage intra-Tenon MMC injection technique resulted in lower postoperative intraocular pressure, less antiglaucoma medication use, and fewer needling revisions compared to the sponge technique.