title: Prevalence and Causes of Visual Impairment and Blindness in Central Iran; The Yazd Eye Study.
abstract: OBJECTIVE
  To determine the prevalence and causes of blindness and visual impairment (VI) in Yazd, central Iran.
  
  
  METHODS
  This population-based, cross-sectional study was performed on adults aged 40-80 years, residing in Yazd district, in 2010-2011. Eligible subjects were selected using cluster random sampling. Each participant underwent an interview and complete ophthalmologic examination. Blindness and VI were defined as best-corrected visual acuity (VA) <3/60 and < 6/18 in the better eye, respectively.
  
  
  RESULTS
  Out of 2,320 eligible individuals, 2,098 participated in the study (90.4% response rate), of whom, 2,023 subjects completed all evaluations. The standardized prevalence of blindness and VI were 0.7% (95% confidence interval [CI], 0.3-1.0%) and 4.4% (95% CI, 3.3-5.4%), respectively which was significantly associated with older age (odd ratio [OR] = 3.2, 95% CI: 1.9-5.2 and OR = 3.1, 95% CI: 2.3-4.2, respectively) and female sex (OR = 3.6, 95% CI: 1.1-12.3 and OR = 1.7, 95% CI: 1.2-2.5, respectively). The proportion of avoidable causes of blindness and VI were 92.9% (95% CI: 80.0-100.0%) and 76.6% (95% CI: 69.2-85.0%), respectively. Major causes of blindness were diabetic retinopathy (50.0%), glaucoma (21.4%) and cataracts (14.3%) whereas main causes of VI were cataracts (41.5%), diabetic retinopathy (17.0%) and age-related macular degeneration (13.8%).
  
  
  CONCLUSIONS
  Diabetic retinopathy, glaucoma, cataract and age-related macular degeneration were the leading causes of blindness and VI in Yazd, most of which are avoidable. Planning for prevention of blindness is highly recommended to decrease the proportion of avoidable blindness.
authors.affiliation: Ophthalmic Epidemiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Katibeh
authors.affiliation: Ophthalmic Epidemiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Pakravan
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Yaseri
authors.affiliation: Ophthalmic Epidemiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Pakbin
authors.affiliation: Department of Ophtalmology, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Soleimanizad
keywords: Blindness; Community Health Planning; Iran; Prevalence