10 eyes of 10 patients underwent PRK,using intraoperative mitomycin C (Mitolem, LEMERY, S.A. de C.V. Mexico D.F. Reg. 136M92 SSA), and 10 eyes for the same patients underwent PRK without intraoperative mitomycin C. A central scan of the total corneal thickness was taken with the confocal microscope (Confoscan 4, Fortune Technologies, Italy) after surgery, and 1 week, 1 month, 3 months, and 6 months after surgery. Corneal epithelial thickness and the Anterior stroma morphology were analyzed by using the NAVIS software V. 3.5.0 (NIDEK, Multi-Instrument Diagnostic System, Japan).