To evaluate and compare the effect of the prophylactic use of two different exposure times of mitomycin C (MMC) 0.02% to inhibit haze formation after photorefractive keratectomy (PRK) for high myopia (> -7.0 D).

Methods: Forty six eyes of twenty three patients, 8 men and 15 women, with high myopia were included in this prospective study. Mean age at the time of PRK plus MMC was 31.7 years. Before PRK, the mean spherical equivalent was -8.50 D (range, -7.25 to -10.50 D). In each patient, one eye was randomly assigned to PRK and a single intraoperative topical application of mitomycin C 0.02% for 15 seconds (Group 1) and the fellow eye, for 30 seconds (Group 2).The inclusion criteria were high myopia, no central corneal opacity and inadequate corneal thickness to allow a safe Laser in situ keratomileusis procedure. Refraction, uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), and slit-lamp evidence of corneal opacity (haze) were evaluated over 12 months

Inclusion Criteria:

• Myopia or compound myopic astigmatism
• Stable refractive error
• No associated eye disease

Exclusion Criteria:

• Diabetes,
• Autoimmune diseases
• Topographic abnormalities