A randomized trial comparing mitomycin C and conjunctival autograft after excision of primary pterygium

To determine the rate of recurrence and complications after bare sclera excision of primary pterygia followed by low-dose mitomycin C (0.2 mg/ml twice daily for five days), placebo (balanced saline solution), or conjunctival autograft.

We performed a prospective, double-masked clinical trial of 64 patients (60 Hispanic) randomly assigned to a treatment group. Twenty-four patients received mitomycin C, 23 conjunctival autograft, and 17 placebo. Recurrence was defined as fibrovascular tissue over the corneoscleral limbus onto clear cornea in the area of previous pterygium excision.

The recurrence rate after mitomycin C and conjunctival autograft was 38% and 39% of eyes, respectively, after mean follow-up (in recurrence-free patients) of 12.3 and 13.5 months, respectively. The recurrence rate after placebo treatment was significantly higher (P = .002), 88%, after mean follow-up (in recurrence-free patients) of 9.3 months. Increasing age was associated with significantly fewer recurrences (P = .006) after controlling for pterygium type (atrophic, noninflamed, or inflamed) and treatment group. The mean time to recurrence varied from 3.7 to 4.8 months; only 6% of recurrences were noted after the sixth postoperative month. Major complications included symblepharon (two), loose autograft (one), and pyogenic granuloma (two). No group had significantly more complications.

Conjunctival autograft and low-dose topical mitomycin C are equally effective as adjunctive treatment after excision of primary pterygia in this young, southern California, predominantly Hispanic population. Both methods have significantly lower rates of recurrence than bare sclera excision alone, and neither is associated with severe complications after one year of follow-up. Increasing patient age is associated with significantly less risk of recurrence.