title: Prevalence of corneal astigmatism in Tohono O'odham Native American children 6 months to 8 years of age.
abstract: OBJECTIVE
  To describe the prevalence of corneal astigmatism in infants and young children who are members of a Native American tribe with a high prevalence of refractive astigmatism.
  
  
  METHODS
  The prevalence of corneal astigmatism was assessed by obtaining infant keratometer (IK4) measurements from 1235 Tohono O'odham children, aged 6 months to 8 years.
  
  
  RESULTS
  The prevalence of corneal astigmatism >2.00 D was lower in the 1- to <2-year-old age group when compared with all other age groups, except the 6- to <7-year-old group. The magnitude of mean corneal astigmatism was significantly lower in the 1- to <2-year age group than in the 5- to <6-, 6- to <7-, and 7- to <8-year age groups. Corneal astigmatism was with-the-rule (WTR) in 91.4% of astigmatic children (≥1.00 D).
  
  
  CONCLUSIONS
  The prevalence and mean amount of corneal astigmatism were higher than reported in non-Native American populations. Mean astigmatism increased from 1.43 D in 1-year-olds to nearly 2.00 D by school age.
authors: Department of Ophthalmology and Vision Science, The University of Arizona, Tucson, Arizona 85711, USA. emharvey@u.arizona.edu
authors: Erin M
authors: EM
authors: Harvey
authors: Velma
authors: V
authors: Dobson
authors: Joseph M
authors: JM
authors: Miller
authors: Jim
authors: J
authors: Schwiegerling
authors: Candice E
authors: CE
authors: Clifford-Donaldson
authors: Tina K
authors: TK
authors: Green
authors: Dawn H
authors: DH
authors: Messer
mesh_terms: D001130:Arizona / Q000453:epidemiology; D001251:Astigmatism / Q000208:ethnology* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007198:Indians, North American; D007223:Infant; D008297:Male; D015995:Prevalence; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D014792:Visual Acuity