Prophylactic Effects of Mitomycin-C on Regression and Haze Formation in Photorefractive Keratectomy

Purpose: To study the effect of prophylactic application of mitomycin-C on regression and corneal haze formation after photorefractive keratectomy (PRK) for high myopia. Methods: Fifty-four eyes of 28 high myopic patients were enrolled in this prospective study. All eyes underwent PRK with application of 0.02% mitomycin-C for two minutes and irrigation with 15-20 ml of normal saline. Follow-up visits were scheduled for the first 7 days and 1,3 and 6 months after surgery. Hanna grading (in the scale of 0 to 4+) was used to assess corneal haze.Results: Mean spherical equivalent refraction (SE) was -7.08 ± 1.11 diopters (D), preoperatively. All eyes were examined on the first 7 days and one month after surgery; 48 eyes (88.9%) were evaluated 3 and 6 months post-surgery. Six months after surgery, all eyes had uncorrected visual acuity (UCVA) of 20/40 or better and 37 eyes (77.1 %) achieved UCVA of 20/20 or better, 45 eyes (93.7%) had SE within ±1.00D of emmetropia. One month postoperatively, 2 eyes (3.7%) had grade 0.5 haze, while at 3and 6 months after surgery no visited eye had haze at all. There was no decrease in best corrected visual acuity after 6 months. In spatial frequencies of 6 and 12 cycle/degree, contrast sensitivity decreased immediately after PRK but increased to the preoperative values by the 6th postoperative month. Conclusions: Mitomycin-C can prevent the development of corneal haze when treating high myopia with PRK. In patients with insufficient corneal thickness for laser in situ keratomileusis (LASIK), mitomycin-C makes a useful adjunct to PRK to provide an alternative treatment for myopia. However, further research with longer follow-up is suggested.