Effect of Needle Revision of Failed Filtering Blebs with Different Concentrations of Mitomycin C

ABSTRACT

PURPOSE: To investigate the efficacy and the risk factors for failure and complications of mitomycin C (MMC)-augmented needle revision (NR) of failed filtering blebs. METHODS: Thirty eyes whose intraocular pressure (IOP) did not decrease after the cutting of scleral flap sutures were recruited. NR was performed with a 26-gauge needle under a slit-lamp. Immediately following NR, all eyes received a subconjunctival injection of 0.1 ml of 0.02 mg/ml (group A) or 0.1 mg/ml (group B) MMC at the adjacent conjunctiva. The mean follow-up period after the last needle revision was 13.2+/-4.2 months. RESULTS: The mean IOP decreased from 25.7+/-10.6 mmHg before surgery to 13.7+/-2.5 mmHg at the last follow-up in group A and from 24.1+/-6.8 mmHg to 17.7+/-8.6 mmHg in group B (group A p=0.001, group B p=0.065). Subconjunctival hemorrhage, hyphema, and a shallow anterior chamber appeared in most cases. However, choridal detachment and avascular changes of the conjunctiva were observed in group B. CONCLUSIONS: IOP decreased in both groups A and B, but severe complications appeared only in group B. NR followed by a subconjunctival injection of 0.02 rather than 0.1 mg/ml is a safe and effective method.