Fixation preference and visual acuity testing in a population-based cohort of preschool children with amblyopia risk factors

Ophthalmology. 2009 Jan;116(1):145-53. doi: 10.1016/j.ophtha.2008.08.031. Epub 2008 Oct 29.


Purpose: To compare the clinical assessment of fixation preference (FP) to visual acuity (VA) in a population-based sample of preschool children with amblyopia risk factors.

Design: Evaluation of diagnostic test in a population-based study.

Participants: 243 children with anisometropia and/or strabismus, aged 30 to 72 months, living in Los Angeles County, CA [corrected]

Methods: Before measuring VA, FP testing was performed at near and usually without correction, using the binocular fixation pattern in children with strabismus >10 prism diopters (Delta), or the induced tropia test for children with strabismus <or=10Delta or without strabismus. We determined the sensitivity and specificity of FP testing for predicting unilateral amblyopia, defined by optotype VA, among children with amblyopia risk factors.

Main outcome measure: Grade of FP.

Results: Sensitivity of FP testing for amblyopia among children with anisometropia was 20% (9/44) and specificity was 94% (102/109). Among strabismic children, sensitivity was 69% (9/13; worse in children 30-47 than 48-72 months old) and specificity was 79% (70/89), with similar findings for esotropia and exotropia.

Conclusion: The ability of FP testing to correctly identify amblyopia in preschool children with amblyopia risk factors is poor. Clinicians should be wary of using FP as a surrogate measure of interocular difference in VA in young children.

Financial disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amblyopia / complications
  • Amblyopia / diagnosis*
  • Amblyopia / physiopathology
  • Child
  • Child, Preschool
  • False Positive Reactions
  • Female
  • Fixation, Ocular / physiology*
  • Humans
  • Male
  • Predictive Value of Tests
  • Prospective Studies
  • Risk Factors
  • Sensitivity and Specificity
  • Strabismus / complications
  • Strabismus / diagnosis
  • Strabismus / physiopathology
  • Vision Tests
  • Vision, Binocular / physiology
  • Visual Acuity / physiology*