title: Prevalence of astigmatism in Native American infants and children.
abstract: OBJECTIVE
  To describe the prevalence of high astigmatism in infants and young children who are members of a Native American tribe with a high prevalence of astigmatism.
  
  
  METHODS
  SureSight autorefraction measurements were obtained for 1461 Tohono O'odham children aged 6 months to 8 years.
  
  
  RESULTS
  The prevalence of astigmatism >2.00 diopters was 30% in Tohono O'odham children during infancy (6 months to <1 year of age) and was 23 to 29% at ages 2 to 7 years. However, prevalence dipped to 14% in children 1 to <2 years of age. At all ages, axis of astigmatism was with-the-rule (plus cylinder axis 90 degrees +/- 30 degrees ) in at least 94% of cases.
  
  
  CONCLUSIONS
  As in non-Native American populations, Tohono O'odham infants show a high prevalence of astigmatism, which decreases in the second year of life. However, the prevalence of high astigmatism in Tohono O'odham children increases by age 2 to <3 years to a level near that seen in infancy and remains at that level until at least age 8 years. Longitudinal data are needed to determine whether the increase in high astigmatism after infancy occurs in infants who had astigmatism as infants or is due to the development of high astigmatism in children who did not show astigmatism during infancy.
authors.affiliation: Department of Ophthalmology and Vision Science, The University of Arizona, Tucson, Arizona 85711, USA. emharvey@u.arizona.edu
authors.forename: Erin M
authors.initials: EM
authors.lastname: Harvey
authors.forename: Velma
authors.initials: V
authors.lastname: Dobson
authors.forename: Candice E
authors.initials: CE
authors.lastname: Clifford-Donaldson
authors.forename: Tina K
authors.initials: TK
authors.lastname: Green
authors.forename: Dawn H
authors.initials: DH
authors.lastname: Messer
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000367:Age Factors; D001130:Arizona / Q000453:epidemiology; D001251:Astigmatism / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data*; D007223:Infant; D008137:Longitudinal Studies; D015995:Prevalence; D014787:Vision Tests