title: Visual acuity, amblyopia, and ocular pathology in 12- to 13-year-old children in Northern Mexico.
abstract: OBJECTIVE
  The aim of this study was to establish visual acuity (VA) and the prevalence of amblyopia and other ocular disorders in a population of 12- to 13-year-old children in Mexico who have not been vision screened.
  
  
  METHODS
  A total of 1,035 12- to 13-year-old children were examined in a field study. The examination included VA, stereopsis, cover testing, refractive retinoscopy, and examination of the red reflex and posterior pole. In cases with unexplained subnormal VA, visually evoked potential/visually evoked response was also performed.
  
  
  RESULTS
  A >or=20/20 in at least one eye was found in 93% of the subjects. Bilateral VA <or=20/40 was found in 0.3% of cases. None of the subjects had bilateral VA <20/60. Amblyopia (<or=20/40) was found in 26 subjects (2.5%). In 10 cases, the cause of subnormal VA was unexplained. Ocular albinism was found in 3 cases, whereas strabismus was found in 24 subjects (2.3%). There were very few ocular opacities or posterior pole abnormalities.
  
  
  CONCLUSIONS
  The visual status in the Mexican 12- to 13-year-old children tested was good. The prevalence of amblyopia was similar to that in other unscreened populations.
authors.affiliation: Department of Ophthalmology, Institute of Clinical Neuroscience, Göteborg University, Göteborg, Sweden.
authors.forename: Josefin
authors.initials: J
authors.lastname: Ohlsson
authors.forename: Gerardo
authors.initials: G
authors.lastname: Villarreal
authors.forename: Anders
authors.initials: A
authors.lastname: Sjöström
authors.forename: Humberto
authors.initials: H
authors.lastname: Cavazos
authors.forename: Maths
authors.initials: M
authors.lastname: Abrahamsson
authors.forename: Johan
authors.initials: J
authors.lastname: Sjöstrand
mesh_terms: D000293:Adolescent; D016117:Albinism, Ocular / Q000453:epidemiology; D000550:Amblyopia / Q000453:epidemiology*; D002648:Child; D005128:Eye Diseases / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D013285:Strabismus / Q000453:epidemiology; D015351:Vision Screening; D014792:Visual Acuity