A Randomized Study of Mitomycin Augmentation in Combined Phacoemulsification and Trabeculectomy

Abstract

The purpose of the study is to determine whether the intraoperative application of subconjunctival mitomycin C (MMC), during combined phacoemulsification and trabeculectomy, is an effective means of improving filtration, defined as overall lower intraocular pressure (IOP) and less antiglaucoma medication use. Twenty-nine patients with a visually significant cataract and glaucoma were randomized, in a double-masked fashion, to receive intraoperative MMC (0.5 mg/ml) or placebo. Follow-up ranged from 6 to 30 months (mean, 20 months). Postoperative visual acuity at 1 year was 20/40 or better in 14 of 15 eyes operated on in the placebo group and 13 of 14 eyes operated on in the MMC group. Intraocular pressure at 8 months averaged 15.2 +/- 1.5 mmHg in the placebo-treated eyes versus 12.3 +/- 1.6 mmHg in the MMC-treated eyes. At 12 months, IOPs averaged 16.2 +/- 1.5 mmHg in the placebo-treated eyes versus 12.6 +/- 1.0 mmHg in the MMC-treated eyes. On average, the MMC group had postoperative IOP levels 3.0 mmHg lower than did the placebo group (P = 0.04) throughout the study. In the placebo group, laser suture lysis was required in a greater number of patients (80% versus 43%) and to a greater extent (mean = 2.0 versus 0.7 suture lysed) (P < 0.05). At 12 months, 5 of the 15 patients in the placebo group required an average of 1.8 medications for IOP control, whereas 0 of the 14 patients in the MMC group needed IOP-lowering medications. A late endophthalmitis developed through an intact bleb in one patient in the MMC group; otherwise, complications were minimal in each group. These results suggest that intraoperative MMC application, during combined phacoemulsification and trabeculectomy surgery, does improve early filtration as shown by overall lower IOPs and less antiglaucoma medication use.