title: Does visual impairment lead to additional disability in adults with intellectual disabilities?
abstract: BACKGROUND
  This study addresses the question to what extent visual impairment leads to additional disability in adults with intellectual disabilities (ID).
  
  
  METHODS
  In a multi-centre cross-sectional study of 269 adults with mild to profound ID, social and behavioural functioning was assessed with observant-based questionnaires, prior to expert assessment of visual function. With linear regression analysis the percentage of variance, explained by levels of visual function, was calculated for the total population and per ID level.
  
  
  RESULTS
  A total of 107/269 participants were visually impaired or blind (WHO criteria). On top of the decrease by ID visual impairment significantly decreased daily living skills, communication & language, recognition/communication. Visual impairment did not cause more self-absorbed and withdrawn behaviour or anxiety. Peculiar looking habits correlated with visual impairment and not with ID. In the groups with moderate and severe ID this effect seems stronger than in the group with profound ID.
  
  
  CONCLUSIONS
  Although ID alone impairs daily functioning, visual impairment diminishes the daily functioning even more. Timely detection and treatment or rehabilitation of visual impairment may positively influence daily functioning, language development, initiative and persistence, social skills, communication skills and insecure movement.
authors.affiliation: Intellectual Disability Medicine, Erasmus Medical Center Rotterdam, Department of General Practice, Rotterdam, The Netherlands. h.evenhuis@erasmusmc.nl
authors.forename: H M
authors.initials: HM
authors.lastname: Evenhuis
authors.forename: L
authors.initials: L
authors.lastname: Sjoukes
authors.forename: H M
authors.initials: HM
authors.lastname: Koot
authors.forename: A C
authors.initials: AC
authors.lastname: Kooijman
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000293:Adolescent; D000328:Adult; D000368:Aged; D015984:Causality; D003147:Communication Disorders / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004314:Down Syndrome / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011788:Quality of Life / Q000523:psychology; D012720:Severity of Illness Index; D012920:Social Behavior Disorders / Q000453:epidemiology* / Q000523:psychology; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000453:epidemiology* / Q000523:psychology; D055815:Young Adult