title: Developmental changes in anterior corneal astigmatism in Tohono O'odham Native American infants and children.
abstract: ABSTRACT Purpose: To describe change in corneal astigmatism in infants and children of a Native American tribe with a high prevalence of astigmatism.
  
  
  METHODS
  Longitudinal measurements of corneal astigmatism were obtained in 960 Tohono O'odham children aged 6 months to <8 years. Change in corneal astigmatism (magnitude (clinical notation), J0, J45) across age in children with high astigmatism (≥2 diopter (D) corneal astigmatism) or low/no astigmatism (<2 D corneal astigmatism) at their baseline measurement was assessed.
  
  
  RESULTS
  Regression analyses indicated that early in development (6 months to <3 years), astigmatism magnitude decreased in the high astigmatism group (0.37 D/year) and remained stable in the low/no astigmatism group. In later development (3 to <8 years), astigmatism decreased in the high (0.11 D/year) and low/no astigmatism groups (0.03 D/year). In 52 children who had data at all three of the youngest ages (6 months to <1 year, 1 to <2 years, 2 to <3 years) astigmatism decreased after infancy in those with high astigmatism (p = 0.021), and then remained stable from age 1-2 years, whereas astigmatism was stable from infancy through age 1 year and increased from age 1-2 years in the low/no astigmatism group (p = 0.026). J0 results were similar, but results on J45 yielded no significant effects.
  
  
  CONCLUSIONS
  The greatest change occurred in highly astigmatic infants and toddlers (0.37 D/year). By age 3 years, change was minimal and not clinically significant. Changes observed were due primarily to change in the J0 component of astigmatism.
authors.affiliation: Department of Ophthalmology and Vision Science, The University of Arizona, Tucson, AZ 85711, USA. emharvey@email.arizona.edu
authors.forename: Erin M
authors.initials: EM
authors.lastname: Harvey
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Miller
authors.forename: Jim
authors.initials: J
authors.lastname: Schwiegerling
authors.forename: Duane
authors.initials: D
authors.lastname: Sherrill
authors.forename: Dawn H
authors.initials: DH
authors.lastname: Messer
authors.forename: Velma
authors.initials: V
authors.lastname: Dobson
mesh_terms: D001130:Arizona; D001251:Astigmatism / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D003316:Corneal Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D019781:Corneal Topography; D005500:Follow-Up Studies; D006801:Humans; D007198:Indians, North American; D007223:Infant; D008913:Minority Groups; D015995:Prevalence