title: Reliability of fixation preference for detecting amblyopia in strabismic patients.
abstract: OBJECTIVE
  To evaluate the association between fixation preference (FP) and amblyopia in strabismic patients.
  
  
  METHODS
  This study includes 50 patients with horizontal, vertical or mixed strabismus of at least 10 prism diopters. Best-corrected monocular visual acuity (VA) was measured using Snellen E-chart and the presence of amblyopia was determined accordingly; FP was evaluated and graded from 0 to 3.
  
  
  RESULTS
  Of 50 patients, including 27 female and 23 male subjects, 29 (58%) patients had FP but 18 (36%) subjects were truly amblyopic. Overall, the sensitivity and specificity of FP for detection of amblyopia was 88.9% and 59.4% respectively. The positive predictive value (PPV) and negative predictive value (NPV) were 55.2% and 90.5% respectively. Sensitivity, PPV and NPV were significantly higher in esotropic as compared to exotropic patients. Strong monocular FP was correlated with more than 3 lines of interocular difference (IOD) in visual acuity (P=0.001).
  
  
  CONCLUSIONS
  Although FP is not an ideal method for diagnosis of strabismic amblyopia, it has high sensitivity, PPV and NPV in esotropic patients and in subjects with more than 3 lines of IOD in VA.
authors.affiliation: Poostchi Eye Research Center, Shiraz Medical University, Shiraz, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Attarzadeh
authors.forename: Abbas
authors.initials: A
authors.lastname: Hoseinirad
authors.forename: Majid
authors.initials: M
authors.lastname: Farvardin
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Talebnejad
authors.forename: Abbas
authors.initials: A
authors.lastname: Alipour