Viscocanalostomy with mitomycin-C: a preliminary study

To compare the results of viscocanalostomy with and without mitomycin-C (MMC).

Retrospective results of 15 standard viscocanalostomy (VCO) operations (Group 1) were compared with the prospective results of 15 VCO operations performed with intraoperative adjunctive MMC (Group 2). MMC (0.2 mg/mL) was applied over and under the superficial scleral flap for 3 minutes in Group 2 before the deep flap was prepared. Each patient was followed up for at least 1 year, and results of examinations in the first 12 months were used in the statistical comparison of the two groups. Surgical success was defined as intraocular pressure (IOP) < or = 18 mmHg.

Preoperative mean intraocular pressures (IOP) in Group 1 and Group 2 were 35.3+/-11.0 and 39.1+/-8.9, respectively. Mean IOP levels at the 12th month were 14.4+/-2.6 and 11.9+/-4.0, respectively, showing a significant decrease in both groups (p<0.001). Postoperative IOP course appeared to be lower in the MMC group, however, the difference was not statistically significant (p=0.554). Complete success rates without medications were 40% in Group 1 and 67% in Group 2. No significant difference was found between the two groups in terms of early and late postoperative complications, pre- and postoperative number of antiglaucoma medications, and surgical success rates at the end of the study period (p>0.05 for all). A significant difference was verified between the two groups of eyes considering the conjunctival bleb types, as low-lying, localized blebs were the most frequent type in Group 1 and thin-walled, avascular blebs were more predominant in the MMC group (p=0.004).

Intraoperative adjunctive MMC use might improve the long-term results of viscocanalostomy by facilitating subconjunctival filtration and might widen the indication range of the technique.