title: Comparison of fixation disparity curve parameters obtained with the Wesson and Saladin fixation disparity cards.
abstract: OBJECTIVE
  This study compared fixation curve parameters with two commercially available fixation disparity cards, one that has been available for several years, the Wesson card, and a new one, the Saladin card.
  
  
  METHODS
  Fixation disparity curves were measured on 50 subjects with the Wesson fixation disparity card and the Saladin fixation disparity card.
  
  
  RESULTS
  The x intercepts were on average more in the base-in direction with the Wesson card than with the Saladin card. The y intercepts were shifted in the exo direction with the Wesson card compared with the Saladin card. The slope with the Wesson card was steeper than the slope obtained with the Saladin card. The distribution of curve types was also different with the two different instruments.
  
  
  CONCLUSIONS
  Fixation disparity curves measured with these two instruments are different, and separate norms should be used for each fixation disparity measurement method.
authors.affiliation: School of Optometry, Indiana University, Bloomington, Indiana 47405, USA.
authors.forename: Janice
authors.initials: J
authors.lastname: Ngan
authors.forename: David A
authors.initials: DA
authors.lastname: Goss
authors.forename: Joseph
authors.initials: J
authors.lastname: Despirito
mesh_terms: D000328:Adult; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D008297:Male