Coelho LM, et al. - During this study, experts comparatively examined the efficacy of mitomycin C (MMC) 0.002% vs MMC 0.02% for the prevention of haze after photorefractive keratectomy (PRK) in patients with myopia or myopic astigmatism. Findings revealed the efficacy of MMC 0.002% in its prevention. Since the long-term safety of MMC remained unproven, its use was recommended in a lower concentration, which would prevent potential complications.