Mitomycin C 0.02 and 0.002% efficacy in preventing haze after photorefractive keratectomy.

PURPOSE: To compare MMC 0.002% efficacy in preventing haze after PRK in relation to MMC 0.02%.

PATIENTS AND METHODS: We conducted a prospective study with patients with myopia or myopic astigmatism undergoing PRK in the same conditions. After PRK, MMC was applied for 30 s in a concentration of 0.02% on the right eye (group 1) and 0.002% on the left eye (group 2). Age, gender, spherical equivalent and haze intensity (1, 3, 6 and 12 months postoperatively) were assessed. Haze was quantified at biomicroscopy (0-4 +). P < 0.05 was considered statistical significant.

RESULTS: We evaluated 130 patients, 77 women and 53 men, with a mean age of 30.2 ± 9 years. The spherical equivalent was - 3.66 D in the group 1 and - 3.77 D in the group 2. In the 1st month after PRK, incidence of haze was 13.9% eyes in group 1 and 14.6% in group 2. In the 3rd month, incidence of haze was 50.0% eyes in group 1 and 48.5% in group 2 which presented with 3 +/4 + traces of haze. In the 12th month, incidence of haze was 7.7% eyes in group 1 and 5.4% in group 2. There was no correlation between haze and age (p = 0.279/0.333), gender (p = 0.345/0.367) or spherical equivalent (p = 0.100/0.054) in groups 1 and 2, respectively. There was no difference in haze between groups 1 and 2 (p = 0.56).

CONCLUSION: MMC 0.002% was effective in preventing haze after PRK. As MMC long-term safety has not been proved, we suggest its use in a lower concentration, in order to prevent potential complications.