title: Risk factors associated with childhood strabismus: the multi-ethnic pediatric eye disease and Baltimore pediatric eye disease studies.
abstract: OBJECTIVE
  To investigate risk factors associated with esotropia or exotropia in infants and young children.
  
  
  METHODS
  Population-based cross-sectional prevalence study.
  
  
  METHODS
  Population-based samples of 9970 children 6 to 72 months of age from California and Maryland.
  
  
  METHODS
  Participants were preschool African-American, Hispanic, and non-Hispanic white children participating in the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Eye Disease Study. Data were obtained by parental interview and ocular examination. Odd ratios and 95% confidence intervals were calculated to evaluate the association of demographic, behavioral, and clinical risk factors with esotropia and exotropia.
  
  
  METHODS
  Odds ratios (ORs) for various risk factors associated with esotropia or exotropia diagnosis based on cover testing.
  
  
  RESULTS
  In multivariate logistic regression analysis, esotropia was associated independently with prematurity, maternal smoking during pregnancy, older preschool age (48-72 months), anisometropia, and hyperopia. There was a severity-dependent association of hyperopia with the prevalence of esotropia, with ORs increasing from 6.4 for 2.00 diopters (D) to less than 3.00 D of hyperopia, to 122.0 for 5.00 D or more of hyperopia. Exotropia was associated with prematurity, maternal smoking during pregnancy, family history of strabismus, female sex, astigmatism (OR, 2.5 for 1.50 to <2.50 D of astigmatism, and 5.9 for ≥2.5 D of astigmatism), and anisoastigmatism in the J0 component (OR, ≥2 for J0 anisoastigmatism of ≥0.25 D).
  
  
  CONCLUSIONS
  Prematurity and maternal smoking during pregnancy are associated with a higher risk of having esotropia and exotropia. Refractive error is associated in a severity-dependent manner to the prevalence of esotropia and exotropia. Because refractive error is correctable, these risk associations should be considered when developing guidelines for the screening and management of refractive error in infants and young children.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Doheny Eye Institute and the Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Cotter
authors.forename: Rohit
authors.initials: R
authors.lastname: Varma
authors.forename: Kristina
authors.initials: K
authors.lastname: Tarczy-Hornoch
authors.forename: Roberta
authors.initials: R
authors.lastname: McKean-Cowdin
authors.forename: Jesse
authors.initials: J
authors.lastname: Lin
authors.forename: Ge
authors.initials: G
authors.lastname: Wen
authors.forename: Jolyn
authors.initials: J
authors.lastname: Wei
authors.forename: Mark
authors.initials: M
authors.lastname: Borchert
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: D015142:Baltimore / Q000453:epidemiology; D002140:California / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004948:Esotropia / Q000175:diagnosis / Q000208:ethnology*; D005006:Ethnicity / Q000706:statistics & numerical data*; D005099:Exotropia / Q000175:diagnosis / Q000208:ethnology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors