Siamak Sabour1,2, Fariba Ghassemi3. 1. Department of Clinical Epidemiology, Safety Promotion and Injury Prevention Research Center, School of Health, Shahid Beheshti University of Medical Sciences, Chamran Highway, Velenjak, Daneshjoo Blvd, Tehran, 198353-5511, Islamic Republic of Iran. s.sabour@sbmu.ac.ir. 2. Safety Promotions and Injury Prevention Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. s.sabour@sbmu.ac.ir. 3. Department of Vitreo-Retinal Surgeries, School of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran.