Treatment Outcomes of Mitomycin C-Augmented Trabeculectomy, Sub-Tenon Injection versus Soaked Sponges, after 3 Years of Follow-up: A Randomized Clinical Trial.

PURPOSE

To report the 3-year outcome of trabeculectomy with mitomycin C (MMC)-soaked sponges versus intra-Tenon injection of MMC in eyes with uncontrolled primary open-angle glaucoma.

DESIGN

Randomized clinical trial.

PARTICIPANTS

Eighty-two consecutive patients with uncontrolled primary open-angle glaucoma.

METHODS

Participants were randomized either to intra-Tenon injection of 0.1 ml of 0.01% MMC (TI group) or 0.02% subconjunctival application of MMC-soaked sponges (TS group). Patients were followed up for 3 years after surgery. The data for 73 eyes were included in the final analysis.

MAIN OUTCOME MEASURES

The primary outcome measure was the surgical success, defined as intraocular pressure (IOP) more than 5 mmHg and <21 mmHg, and IOP reduction of 20% or more from baseline, no reoperation for glaucoma, and no loss of light perception vision. Secondary outcome measures were IOP, glaucoma medications, best-corrected visual acuity (VA), bleb morphologic features according to the Indiana Bleb Appearance Grading Scale, complications, and endothelial cell count changes.

RESULTS

The cumulative probability of success at 3-year follow-up was 72.2% in the TI group and 65.1% in the TS group (P = 0.30). Uncontrolled IOP was the most common reason for failure. The mean preoperative IOP was 22.4±4.6 mmHg with an average of 3.1±1.0 medications. At 3 years, final IOP was 15.3±3.7 mmHg in the TI group and 16.4±3.5 mmHg in the TS group (P = 0.55). Mean glaucoma number of medications was 0.9±1.1 and 1.1±1.1 in the TI and TS groups, respectively (P = 0.54). Blebs tended to be more diffuse (P = 0.032), less vascularized (P = 0.013), and more shallow (P = 0.012) after intra-Tenon injection. Visual outcomes and endothelial cell changes were similar in both groups (P = 0.47 and P = 0.94, respectively).

CONCLUSIONS

Although the success rate and IOP reduction were comparable with both techniques, bleb morphologic parameters were more favorable after intra-Tenon injection of 0.1 ml of 0.01% MMC.