Background and objective: The purposes of this study are to examine the complications and results of a novel approach to the use of mitomycin-C in pterygium surgery; to identify the lowest effective dosage required to prevent recurrence; and to select those high-risk pterygia that could benefit from mitomycin-C use.
Patients and methods: One hundred thirty-five eyes of 128 patients considered at high risk for recurrence of pterygium were treated with a single, intraoperative, subconjunctival injection of mitomycin-C at the site of excision. Three different dosages-0.2, 0.1, and 0.05 ml-at a strength of 0.5 mg/ml were used. The eyes were observed for 10 months to 3 years.
Results: There were only two recurrences (1.5%); both occurred in eyes that had undergone previous pterygium surgery. One recurrence happened with the 0.2-ml dosage, and the other with the 0.1-ml dosage. These recurrences occurred in association with early wound dehiscence, which essentially became a bare sclera susceptible to pterygium regrowth. Complications included temporary and prolonged discomfort, tearing, hyperemia, subconjunctival hemorrhage, wound dehiscence, and pigment accumulation. No vision-threatening side effects were noted.
Conclusions: The persistence and intensity of discomfort noted at the higher dosage has prompted these authors to suggest that only high-risk pterygia should receive mitomycin-C. Conjunctival flaps should always be used to cover the sclera up to the limbus and to localize the mitomycin-C to prevent its migration. A single dose of not more than 0.05 ml at a strength of 0.5 mg/ml subconjunctivally gives the same results as multiple drops, but with far less morbidity.