title: The prevalence of refractive errors in 6- to 15-year-old schoolchildren in Dezful, Iran.
abstract: OBJECTIVE
  To determine the prevalence of refractive errors, among 6- to 15-year-old schoolchildren in the city of Dezful in western Iran.
  
  
  METHODS
  In this cross-sectional study, 1375 Dezful schoolchildren were selected through multistage cluster sampling. After obtaining written consent, participants had uncorrected and corrected visual acuity tests and cycloplegic refraction at the school site. Refractive errors were defined as myopia [spherical equivalent (SE) -0.5 diopter (D)], hyperopia (SE ≥ 2.0D), and astigmatism (cylinder error > 0.5D).
  
  
  RESULTS
  1151 (83.7%) schoolchildren participated in the study. Of these, 1130 completed their examinations. 21 individuals were excluded because of poor cooperation and contraindication for cycloplegic refraction. Prevalence of myopia, hyperopia, and astigmatism were 14.9% (95% confidence interval (CI): 10.1-19.6), 12.9% (95% CI: 7.2-18.6), and 45.3% (95% CI: 40.3-50.3), respectively. Multiple logistic regression analysis showed an age-related increase in myopia prevalence (p << 0.001) and a decrease in hyperopia prevalence (p << 0.001). There was a higher prevalence of myopia in boys (p<<0.001) and hyperopia in girls (p = 0.007).
  
  
  CONCLUSIONS
  This study showed a considerably high prevalence of refractive errors among the Iranian population of schoolchildren in Dezful in the west of Iran. The prevalence of myopia is considerably high compared to previous studies in Iran and increases with age.
authors.affiliation: Dezful University of Medical Sciences, Dezful, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Norouzirad
authors.affiliation: Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Hashemi
authors.affiliation: Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Abbasali
authors.initials: A
authors.lastname: Yekta
authors.affiliation: Dezful University of Medical Sciences, Dezful, Iran.
authors.forename: Fereidon
authors.initials: F
authors.lastname: Nirouzad
authors.affiliation: Refractive Errors Research Center, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Ostadimoghaddam
authors.affiliation: Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Negareh
authors.initials: N
authors.lastname: Yazdani
authors.affiliation: Noor Research Center for Ophthalmic Epidemiology, Noor eye hospital, Tehran, Iran.
authors.forename: Nooshin
authors.initials: N
authors.lastname: Dadbin
authors.affiliation: Noor Research Center for Ophthalmic Epidemiology, Noor eye hospital, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Javaherforoushzadeh
authors.affiliation: Department of Epidemiology, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Khabazkhoob
keywords: Children; Epidemiology; Middle-east; Refractive errors