Single intraoperative application versus postoperative mitomycin C eye drops in pterygium surgery

Purpose: To determine the minimum effective dosage, most effective route of administration and long-term effects of mitomycin C for prevention of recurrence after pterygium surgery. Methods: In a prospective, masked study, 227 patients undergoing surgery for primary pterygia were assigned randomly to five groups: group 1 received a single intraoperative application of 0.2 mg/ml mitomycin C for 3 minutes; group 2 received a single intraoperative application of 0.4 mg/ml mitomycin C for 3 minutes; group 3 received mitomycin C eye drops 0.2 mg/ml three times daily for 7 days; group 4 received mitomycin C eye drops 0.4 mglml three times daily for 14 days; group 5 acted as a control (surgery alone), Results: After a mean follow-up time of 28 months, recurrence rates of 6.66%, 4.08%, 4.26%, 4.44%, and 29.27%, respectively, were observed. Statistical analysis showed significant differences between groups receiving mitomycin C and the control (P less than or equal to 0.001). There was no statistical difference among treated groups (P greater than or equal to 0.0681). No complications of therapy were observed. Conclusion: These results support the efficacy and relative safety of a single, low-concentration, intraoperative application of mitomycin C in pterygium surgery together with the use of a conjunctival flap, avoiding excessive cauterization of the sclera and leaving bare sclera.