Surgical Outcome and Complications of Preoperative Subconjunctival Injection of Mitomycin C in Filtering Surgery

ABSTRACT

PURPOSE: We conducted a retrospective study to evaluate preoperative subconjunctival injection of mitomycin C (MMC) for surgical outcome and postoperative complications in trabeculectomy. METHODS: Twenty-eight eyes (22 patients) with glaucoma patients who were followed up for at least 6 months were injected subconjunctivally with 0.02 ml of 0.4mg/ml MMC (0.008 mg) mixed with 0.03 ml of 2% lidocaine before making the conjunctival incision and then trabeculectomy was performed after 5 minutes. RESULTS: Postoperative mean follow-up period was 21.1 months, preoperative mean IOP was 33.9 mmHg. Postoperative mean IOP at 1, 3, 6, 12month, and at the last follow-up were 9.0, 9.3, 9.5, 11.0, and 11.2 mmHg, respectively. There were statistically significant decreases of IOP in postoperation compared preoperation. When postoperative IOP were controlled below 21 mmHg and reduced under 30% compared with preoperative IOP, postoperative success rate at 1, 3, 6, 12 month, and at the last follow-up were 100%, 96%, 89%, 89%, and 86%, respectively. Postoperative complications were avascular cystic bleb in 8 eyes (29%), transient hypotony in 6 eyes (21%), shallow anterior chamber in 5 eyes (18%). Early aqueous leaking from conjunctival wound was in 4 eyes (14%). CONCLUSIONS: It is suggested that the preoperative subconjunctival injection of MMC of high concentration be used in filtering surgery. But the determination of volume and concentration is needed to prevent postoperative complications and long-term IOP lowering effect.