Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 55 1 2017 02 05 42 48 EN Hassan Hashemi Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran. Yahya Salimi Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran. AND Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Poopak Pir Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran. Soheila Asgari Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 14 2016 10 10 Photorefractive keratectomy (PRK) is a safe and effective surgical keratorefractive technique which is done with the application of mitomycin-C (MMC) in cases of high myopia to prevent the formation of corneal haze This study was conducted to evaluate 3-year visual acuity and quality outcomes of PRK-MMC in high myopia. This before-after study was conducted on 20 individuals (40 eyes) with myopia more than 6.0 diopter (D). Visual acuity and quality indices were evaluated before and three years after the procedure and their stability was examined between the 1st and 3rd years. At 3 years after surgery, mean uncorrected visual acuity was 0.03±0.06 in the logarithm of minimum angle of resolution (logMAR) unit which showed a significant improvement when compared to baseline (P<0.001) and means best corrected visual acuity was 0.03±0.06 logMAR, which showed no significant difference (P=0.730). Manifest refraction spherical equivalent (MRSE) at 3 years (-0.12±0.2D) was significantly decreased when compared to baseline (P<0.001), but it did not change significantly after the 1st year and was stable (P=0.368). Mean coma and spherical aberration 3 years postoperatively were -0.54±0.26 µm and 0.46±0.19 µm, respectively, and neither parameter showed significant differences when compared to baseline (P<0.001). No significant change was found in mesopic contrast sensitivity. The long-term results of this study showed that PRK-MMC could be regarded an effective, safe, and stable procedure in patients with myopia more than 6.0 D. https://acta.tums.ac.ir/index.php/acta/article/view/4974 https://acta.tums.ac.ir/index.php/acta/article/download/4974/4888