Sponge Application of Mitomycin C vs Sub-Tenon Injection in Trabeculectomy: A Randomized Controlled Trial.

AIMS AND

BACKGROUND

Glaucoma represents a major driver of irreversible blindness globally, with intraocular pressure (IOP) reduction serving as the primary therapeutic objective. Trabeculectomy (TE), often augmented with mitomycin C (MMC), is considered the gold standard surgical treatment; however, its success is frequently compromised by postoperative fibrosis. Various MMC delivery techniques-such as sponge application and sub-Tenon injection (STI)-differ in their drug distribution profiles and may consequently affect surgical outcomes. Accordingly, we aimed to evaluate and compare the efficacy and safety of TE performed with sponge-applied MMC against STI-MMC.

MATERIALS AND

METHODS

This prospective, randomized, controlled clinical trial enrolled 50 patients having primary or secondary glaucoma who were randomly allocated to undergo TE with either MMC sponge application (group A, n = 25) or STI-MMC (group B, n = 25) and followed for 12 months. The primary outcome measures included IOP reduction, while secondary outcomes assessed bleb morphology using the Indiana Bleb Appearance Grading Scale (IBAGS), bleb integrity via Seidel testing, and the requirement for postoperative glaucoma medications.

RESULTS

Both groups achieved significant IOP reductions without intergroup differences at all postoperative intervals (p > 0.05). Bleb morphology differed significantly, with higher localized blebs in group A and flatter and more diffuse blebs in group B (p < 0.001). There were no significant differences in bleb vascularity or integrity. Postoperative medication needs were comparable (p = 0.732).

CONCLUSION

Both STI-MMC and sponge-applied MMC are equally effective for IOP control, though STI may produce more diffuse blebs, potentially reducing long-term complications. Further long-term studies are warranted.

CLINICAL SIGNIFICANCE: This study demonstrates STI-MMC noninferiority compared to sponge-applied MMC in achieving sustained IOP reduction after TE while highlighting distinct bleb morphologies with potential safety implications. These findings advocate for individualized MMC selection based on patient-specific risk factors, balancing technical simplicity with potential long-term safety.

CLINICAL TRIAL REGISTRATION: Retrospectively registered at ClinicalTrials.gov (Identifier: NCT06925412).

HOW TO CITE THIS ARTICLE: Abdelhafeez SM, Mohammed Mohammed HE, Tharwat E, et al. Sponge Application of Mitomycin C vs Sub-Tenon Injection in Trabeculectomy: A Randomized Controlled Trial. J Curr Glaucoma Pract 2025;19(4):199-207.