Use of mitomycin c with conjunctival autograft in pterygium surgery in Asian-Canadians

Abstract

Objective To determine whether using mitomycin C (MMC) before applying conjunctival autograft is better than conjunctival autograft alone in preventing the recurrence of pterygia in an Asian-Canadian population. Design Nonrandomized, retrospective, comparative case series. Participants A total of 159 patients were included in the study. Seventy patients (76 eyes) received MMC (0.25 mg/ml for 1 minute) with conjunctival autograft; 89 patients (98 eyes) received conjunctival autograft alone. Intervention All patients had primary (first-occurrence) pterygia excised and conjunctival autograft applied with or without MMC adjunct. Main outcome measures Recurrence of pterygia was monitored for up to 1 year after the operation. Any complications (e.g., scleral thinning and necrosis) were documented. Results Patients’ pterygia were examined on presentation and were graded 1 through 3. Grade 1 pterygia were fibrovascular proliferations extending up to one quarter the diameter of the cornea; grade 2 extended between one quarter to one half the distance across the cornea; and grade 3 extended beyond the visual axis. In the more severe pterygia group (grades 2 and 3 combined), there was significantly less pterygium recurrence in the MMC/autograft group (7%) compared with the autograft alone-treated group (26%). There was no significant difference in recurrence between groups for less severe grade pterygia (grade 1). The recurrence rate of all pterygia in the MMC/autograft group was 9% compared with 18% for the conjunctival autograft group. This difference was not statistically significant, however, because of a small sample size. There were no significant complications in either group and no difference between groups in complication rates. Conclusions The authors suggest using MMC in patients with more severe pterygia as an adjunct to conjunctival autograft to lower the recurrence rate. Combining the use of MMC with conjunctival autograft allows for decreased dosage and time of intraoperative exposure of mitomycin, thereby making it safer for application.