Evaluating the long-term efficacy of short-duration 0.1 mg/ml and 0.2 mg/ml MMC in primary trabeculectomy for primary adult glaucoma.

OBJECTIVE: To evaluate safety and efficacy of 0.1 mg/ml versus 0.2 mg/ml mitomycin-C (MMC), applied for 1 min subconjunctivally, during trabeculectomy for primary adult glaucoma in previously un-operated eyes.

MATERIALS AND METHODS: This is a randomised controlled, non-inferior, clinical trial consisting of 50 consecutive POAG or CPACG patients uncontrolled on maximal hypotensive therapy, meeting all inclusion criteria. Patients were randomized into two groups and underwent a standard limbus-based trabeculectomy with MMC: Group I, 0.1 mg/ml and Group II, 0.2 mg/ml. The pre-operative and post-operative intraocular pressure (IOP), bleb morphology, and visual acuity were recorded every 6 months for 2 years. Complete success (primary outcome) was defined as IOP ≤ 15 mmHg without any additional medications at the end of 2 years.

RESULTS: The average age of patients was 62.6 ± 9.8 years and 61.2 ± 8.1 years in Group 1 and 2, respectively; p = 0.57. The mean preoperative IOP was 22.5 ± 1.4 mmHg and 23.3 ± 1.8 mmHg; p = 0.10. The mean IOP at 2 years was 11.1 ± 1.6 mmHg and 10.8 ± 2.8 mmHg, a mean reduction in IOP of 50.6 ± 1.23 %, and 53.7 ± 2.25 % in Group I and II, respectively. The complete success was 92.0 % and 91.7 % in the two groups, respectively (p = 0.99), and there was one failure (Group II, post trauma). A wider bleb extent and larger areas of thin, transparent conjunctiva over the bleb were seen with the 0.2 mg/ml MMC group (p < 0.001) and in PACG eyes; p < 0.04.

CONCLUSION: A 1-min subconjunctival application of low dose 0.1 mg/ml MMC is non-inferior to 0.2 mg/ml and is probably a safer alternative, as thinning of the bleb is significantly less frequent in the long term.