title: Association between childhood strabismus and refractive error in Chinese preschool children.
abstract: OBJECTIVE
  To investigate the association between concomitant esotropia or concomitant exotropia and refractive error in preschool children.
  
  
  METHODS
  A population-based sample of 5831 children aged 3 to 6 years was selected from all kindergartens in a representative county (Yuhuatai District, Nanjing, Jiangsu Province) of Nanjing, China. Clinical examinations including ocular alignment, ocular motility, visual acuity, optometry, stereopsis screening, slit lamp examination and fundus examination were performed by trained ophthalmologists and optometrists. Odd ratios (OR) and 95% confidence intervals (95% CI) were calculated to evaluate the association of refractive error with concomitant esotropia and concomitant exotropia.
  
  
  RESULTS
  In multivariate logistic regression analysis, concomitant esotropia was associated independently with spherical equivalent anisometropia (OR, 3.15 for 0.50 to <1.00 diopter (D) of anisometropia, and 7.41 for > = 1.00 D of anisometropia) and hyperopia. There was a severity-dependent association of hyperopia with the development of concomitant esotropia, with ORs increasing from 9.3 for 2.00 to <3.00 D of hyperopia, to 180.82 for > = 5.00 D of hyperopia. Concomitant exotropia was associated with astigmatism (OR, 3.56 for 0.50 to 1.00 D of astigmatism, and 1.9 for <0.00 D of astigmatism), myopia (OR, 40.54 for -1.00 to <0.00 D of myopia, and 18.93 for <-1.00 D of myopia), and hyperopia (OR, 67.78 for 1.00 to <2.00 D of hyperopia, 23.13 for 2.00 to <3.00 D of hyperopia, 25.57 for 3.00 to <4.00 D of hyperopia, and 8.36 for 4.00 to <5.00 D of hyperopia).
  
  
  CONCLUSIONS
  This study highlights the close associations between refractive error and the prevalence of concomitant esotropia and concomitant exotropia, which should be considered when managing childhood refractive error.
authors: First Clinical Medical College of Nanjing Medical University, Jiangsu Province, China.
authors: Hui
authors: H
authors: Zhu
authors: Department of ophthalmology, Wuxi No.2 People's Hospital, Jiangsu Province, China.
authors: Jia-Jia
authors: JJ
authors: Yu
authors: Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Jiangsu Province, China.
authors: Rong-Bin
authors: RB
authors: Yu
authors: Maternal and Child Healthcare Hospital of Yuhua District, Nanjing, China.
authors: Hui
authors: H
authors: Ding
authors: Maternal and Child Healthcare Hospital of Yuhua District, Nanjing, China.
authors: Jing
authors: J
authors: Bai
authors: Maternal and Child Healthcare Hospital of Yuhua District, Nanjing, China.
authors: Ji
authors: J
authors: Chen
authors: Department of Ophthalmology, Jiangsu Province Hospital, the First Affiliated Hospital with Nanjing Medical University, Jiangsu Province, China.
authors: Hu
authors: H
authors: Liu
mesh_terms: D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D004948:Esotropia / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D005099:Exotropia / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012030:Refractive Errors / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology