title: Causes of visual impairment among patients referred to a visual rehabilitation clinic in Iran.
abstract: OBJECTIVE
  Epidemiologic evaluation and investigating the causes of visual impairment in any society is a matter of concern and has a direct effect on the country's health care planning. In this study we describe causes of low vision and blindness in Iranian patients referred to rehabilitation clinics for taking vision aids.
  
  
  METHODS
  In this cross-sectional study, visual acuity was classified based on best-corrected visual acuity in the better eye according to the World Health Organization definition (blindness, visual acuity [VA] < 20 / 400; severe visual impairment, VA < 20 / 200-20 / 400; mild to moderate visual impairment, VA < 20 / 60-20 / 200). The causes of blindness and low vision were determined using the 10th version of International Classification of Diseases based on the main cause in both eyes. To describe data, we used mean ± SD and frequency.
  
  
  RESULTS
  The study included 432 patients, 65% male, with a mean age of 43.6 ± 25.5 years (range, 3 to 92 years). Mild to moderate visual impairment, severe visual impairment and blindness were present in 122 (28.8%), 196 (46.4%) and 105 (24.8%) of the patients, respectively. The main causes of visual impairment were retinal and choroidal diseases (74.5%), optic nerve and optic tract diseases (9.8%), vitreous and globe disorders (5.3%), congenital cataract (3.1%), and glaucoma (2.6%). The distribution pattern of the causes was similar in all age subgroups.
  
  
  CONCLUSIONS
  Diseases of the retina and choroid are the main cause of visual impairment among patients referred to an academic visual rehabilitation clinic in Iran.
authors.affiliation: Ophthalmic Research Centre, Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. arramezani@gmail.com
authors.forename: Alireza
authors.initials: A
authors.lastname: Ramezani
authors.forename: Maasome
authors.initials: M
authors.lastname: Pardis
authors.forename: Nasrin
authors.initials: N
authors.lastname: Rafati
authors.forename: Mohsen
authors.initials: M
authors.lastname: Kazemi-Moghaddam
authors.forename: Marzieh
authors.initials: M
authors.lastname: Katibeh
authors.forename: Pooya
authors.initials: P
authors.lastname: Rostami
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Dehghan
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Javadi
authors.forename: Zahra
authors.initials: Z
authors.lastname: Rabbanikhah
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001296:Audiovisual Aids; D001766:Blindness / Q000453:epidemiology* / Q000534:rehabilitation; D002648:Child; D002675:Child, Preschool; D015862:Choroid Diseases / Q000453:epidemiology* / Q000534:rehabilitation; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009901:Optic Nerve Diseases / Q000453:epidemiology / Q000534:rehabilitation; D012017:Referral and Consultation / Q000706:statistics & numerical data*; D012047:Rehabilitation Centers / Q000706:statistics & numerical data*; D012164:Retinal Diseases / Q000453:epidemiology* / Q000534:rehabilitation; D015354:Vision, Low / Q000453:epidemiology* / Q000534:rehabilitation; D055815:Young Adult