PURPOSE:To evaluate the safety and efficacy of 5 seconds of mitomycin-C (MMC) application during photorefractive keratectomy (PRK) for low myopia. SETTING:Basir Eye Clinic, Tehran, Iran. DESIGN:Prospective randomized sham-controlled double-masked clinical trial. METHODS:Patients with low myopia and an ablation depth of less than 65 μm were recruited. One eye of each patient was included in the study and was randomly assigned to receive intraoperative topical MMC 0.02% for 5 seconds or a balanced salt solution in the same manner (control group). Corneal haze development during the 6 months after the PRK was the main outcome measure. RESULTS:Of the 184 eligible patients (MMC = 93; control = 91), 152 (78 and 74, respectively) completed the follow-up. The postoperative haze grade was significantly lower in the MMC group (P=.01). The mean endothelial cell density was not significantly different between the MMC group and the control group preoperatively (2879.97 cells/mm(2) ± 298.04 [SD] versus 2819.69 ± 303.89 cells/mm(2); P=.22) or 6 months postoperatively (2878.79 ± 283.04 cells/mm(2) versus 2878.79 ± 283.04 cells/mm(2); P=.25). No notable ocular complication occurred throughout the study. CONCLUSION:Short-time application of MMC 0.02% was safe and effective in preventing haze formation in eyes having PRK with an ablation depth of less than 65 μm compared with matched controls up to 6 months. FINANCIAL DISCLOSURE:No author has a financial or proprietary interest in any material or method mentioned.