title: Risk factors for astigmatism in preschool children: the multi-ethnic pediatric eye disease and Baltimore pediatric eye disease studies.
abstract: OBJECTIVE
  To evaluate risk factors for astigmatism in a population-based sample of preschool children.
  
  
  METHODS
  Population-based cross-sectional study.
  
  
  METHODS
  Population-based samples of 9970 children ages 6 to 72 months from Los Angeles County, California, and Baltimore, Maryland.
  
  
  METHODS
  A cross-sectional study of children participating in the Multiethnic Pediatric Eye Disease Study and the Baltimore Eye Disease Study was completed. Data were obtained by clinical examination or by in-person interview. Odds ratios and 95% confidence intervals (CI) were calculated to evaluate potential associations between clinical, behavioral, or demographic factors and astigmatism.
  
  
  METHODS
  Odds ratios (ORs) for various risk factors associated with astigmatism.
  
  
  RESULTS
  Participants with myopia (≤-1.0 diopters) were 4.6 times as likely to have astigmatism (95% CI, 3.56-5.96) than those without refractive error, whereas participants with hyperopia (≥+2.00 diopters) were 1.6 times as likely (95% CI, 1.39-1.94). Children 6 to <12 months of age were approximately 3 times as likely to have astigmatism than children 5 to 6 years of age (95% CI, 2.28-3.73). Both Hispanic (OR, 2.38) and African-American (OR, 1.47) children were as likely to have astigmatism than non-Hispanic white children. Furthermore, children whose mothers smoked during pregnancy were 1.46 times (95% CI, 1.14-1.87) as likely to have astigmatism than children whose mothers did not smoke.
  
  
  CONCLUSIONS
  In addition to infancy, Hispanic and African-American race/ethnicity and correctable/modifiable risk factors such as myopia, hyperopia, and maternal smoking during pregnancy are associated with a higher risk of having astigmatism. Although the prevalence of smoking during pregnancy is typically low, this association may suggest etiologic pathways for future investigation.
  
  
  BACKGROUND
  The authors have no proprietary or commercial interest in any of the materials discussed in this article.
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
authors.forename: Roberta
authors.initials: R
authors.lastname: McKean-Cowdin
authors.forename: Rohit
authors.initials: R
authors.lastname: Varma
authors.forename: Susan A
authors.initials: SA
authors.lastname: Cotter
authors.forename: Kristina
authors.initials: K
authors.lastname: Tarczy-Hornoch
authors.forename: Mark S
authors.initials: MS
authors.lastname: Borchert
authors.forename: Jesse H
authors.initials: JH
authors.lastname: Lin
authors.forename: Ge
authors.initials: G
authors.lastname: Wen
authors.forename: Stanley P
authors.initials: SP
authors.lastname: Azen
authors.forename: Mina
authors.initials: M
authors.lastname: Torres
authors.forename: James M
authors.initials: JM
authors.lastname: Tielsch
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.forename: Michael X
authors.initials: MX
authors.lastname: Repka
authors.forename: Joanne
authors.initials: J
authors.lastname: Katz
authors.forename: Josephine
authors.initials: J
authors.lastname: Ibironke
authors.forename: Lydia
authors.initials: L
authors.lastname: Giordano
mesh_terms: D001741:Black or African American / Q000208:ethnology*; D001251:Astigmatism / Q000175:diagnosis / Q000208:ethnology*; D015142:Baltimore / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D006630:Hispanic or Latino / Q000208:ethnology*; D006801:Humans; D006956:Hyperopia / Q000208:ethnology; D007223:Infant; D015141:Los Angeles / Q000453:epidemiology; D009216:Myopia / Q000208:ethnology; D016017:Odds Ratio; D042262:Retinoscopy; D012307:Risk Factors; D011795:Surveys and Questionnaires; D044465:White People / Q000208:ethnology*