title: Strabismus and binocular functions in a sample of Swedish children aged 4-15 years.
abstract: OBJECTIVE
  To investigate strabismus, head posture, nystagmus, stereoacuity, ocular motility, near point of convergence (NPC) and accommodative convergence to accommodation ratio (AC/A) in a sample of Swedish children.
  
  
  METHODS
  A prospective cross-sectional study was carried out on 143 children, 4-15 years of age.
  
  
  RESULTS
  Heterotropia was found in five children (3.5%), four with esotropia and one with exotropia. One child with esotropia had a slight overaction of both inferior oblique muscles. Heterophoria was found in 37 children (26%) at near and/or distance fixation and it was four times more common at near than at distance. In 29 children, heterophoria was found at one distance only and orthophoria at the other. Orthophoria at both near and distance fixation was noted in 101 children (70.5%). The near point of convergence was < or =6 cm in 97% of the children and 97% had stereoacuity of 60" or better. In the whole group, the median AC/A ratio calculated with the heterophoria method was 5.6/1 prism diopters/diopters (PD/D) and with the gradient method, 1.3/1 PD/D. No anomalous head postures or nystagmus were observed and all children had normal versions.
  
  
  CONCLUSIONS
  In this study, 143 well-defined children were investigated with a battery of accurately described tests, commonly used in clinical practice. These results are in agreement with those of other studies examining one or few variables in larger populations and the authors therefore conclude that their results may be used for comparisons with different patient groups.
authors: Institute of Clinical Neuroscience, Section of Ophthalmology, Department of Paediatrics, The Sahlgrenska Academy at Göteborg University, Ostra, SE-416 85 Göteborg, Sweden. eva.aring@vgregion.se
authors: Eva
authors: E
authors: Aring
authors: Marita Andersson
authors: MA
authors: Grönlund
authors: Susann
authors: S
authors: Andersson
authors: Anna-Lena
authors: AL
authors: Hård
authors: Jan
authors: J
authors: Ygge
authors: Ann
authors: A
authors: Hellström
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003867:Depth Perception; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000503:physiopathology; D011446:Prospective Studies; D013285:Strabismus / Q000503:physiopathology*; D013548:Sweden; D015348:Vision, Binocular