title: Prevalence and risk factors for common vision problems in children: data from the ALSPAC study.
abstract: OBJECTIVE
  To estimate the distribution and predictors of some common visual problems (strabismus, amblyopia, hypermetropia) within a population-based cohort of children at the age of 7 years.
  
  
  METHODS
  Children participating in a birth cohort study were examined by orthoptists who carried out cover/uncover, alternate cover, visual acuity and non-cycloplegic refraction tests. Prospectively collected data on potential risk factors were available from the study.
  
  
  RESULTS
  Data were available for 7825 seven-year-old children. 2.3% (95% CI 2.0% to 2.7%) had manifest strabismus, 3.6% (95% CI 3.3% to 4.1%) had past/present amblyopia, and 4.8% (95% CI 4.4% to 5.3%) were hypermetropic. Children from the lowest occupational social class background were 1.82 (95% CI 1.03% to 3.23%) times more likely to be hypermetropic than children from the highest social class. Amblyopia (p = 0.089) and convergent strabismus (p = 0.066) also tended to increase as social class decreased.
  
  
  CONCLUSIONS
  Although strabismus has decreased in the UK, it and amblyopia remain common problems. Children from less advantaged backgrounds were more at risk of hypermetropia and to a lesser extent of amblyopia and convergent strabismus. Children's eye-care services may need to take account of this socio-economic gradient in prevalence to avoid inequity in access to care.
authors.affiliation: Centre for Child and Academic Health, University of Bristol, Bristol, UK. cathy.williams@bristol.ac.uk
authors.forename: C
authors.initials: C
authors.lastname: Williams
authors.forename: K
authors.initials: K
authors.lastname: Northstone
authors.forename: M
authors.initials: M
authors.lastname: Howard
authors.forename: I
authors.initials: I
authors.lastname: Harvey
authors.forename: R A
authors.initials: RA
authors.lastname: Harrad
authors.forename: J M
authors.initials: JM
authors.lastname: Sparrow
mesh_terms: D000550:Amblyopia / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D002648:Child; D004739:England / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D008297:Male; D012923:Social Class; D013285:Strabismus / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D014786:Vision Disorders / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D014792:Visual Acuity