title: Visual abilities of students with severe developmental delay in special needs education - a vision screening project in Northern Jutland, Denmark.
abstract: OBJECTIVE
  To investigate the visual abilities of students with severe developmental delay (DD) age 6-8 starting in special needs education.
  
  
  METHODS
  Between 1 January 2000 and 31 December 2008, we screened all students with severe DD starting in special needs schools in Northern Jutland, Denmark for vision. All students with visual acuities ≤6/12 were refractioned and examined by an ophthalmologist.
  
  
  RESULTS
  Of 502 students, 56 (11%) had visual impairment (VI) [visual acuity (VA) ≤ 6/18], of which 21 had been previously undiagnosed. Legal blindness was found in 15 students (3%), of whom three had previously been undiagnosed. Students tested with preferential looking systems (N = 78) had significantly lower visual acuities [VA (decimal) = 0.55] than students tested with ortho types [VA (decimal) = 0.91] and had problems participating in the colour and form tests, possibly due to cerebral VI. The number of students with decreased vision identified by screening decreased significantly during the study period (r = 0.724, p = 0.028). The number of students needed to be screened to find one student with VI was 24 and to identify legal blindness 181 needed to be screened.
  
  
  CONCLUSIONS
  Visual impairment is a common condition in students with severe DD. Despite increased awareness of VI in the school and health care system, we continued to find a considerable number of students with hitherto undiagnosed decreased vision.
authors.affiliation: Department of Ophthalmology, Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark. lgw@rn.dk
authors.forename: Lotte G
authors.initials: LG
authors.lastname: Welinder
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Baggesen
mesh_terms: D002648:Child; D055253:Color Vision / Q000502:physiology; D003718:Denmark / Q000453:epidemiology; D002658:Developmental Disabilities / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D019988:Children with Disabilities; D004519:Education, Special; D005260:Female; D005556:Form Perception / Q000502:physiology; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D014786:Vision Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D015351:Vision Screening / Q000379:methods*; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D014796:Visual Perception / Q000502:physiology; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*