title: Quantification of the Brückner test for strabismus.
abstract: OBJECTIVE
  To measure quantitatively the change in the coaxial fundus reflex with varying degrees of ocular misalignment.
  
  
  METHODS
  The coaxial fundus reflex was imaged with a charge coupled device camera under conditions of simulated ocular misalignment ranging from 0 degrees to 7 degrees of fixation eccentricity. The effects of refractive error and pupil size were controlled. Average gray scale brightness values were calculated for each bright pupil image after some image processing was performed on the raw images.
  
  
  RESULTS
  A reliable, sharply delineated, minimum brightness at foveal fixation was observed.
  
  
  CONCLUSIONS
  It is estimated that this technique can be automated to detect the presence of 2 degrees to 3 degrees of ocular misalignment based on the difference in brightness of the bright pupil images between the two eyes.
authors.affiliation: Department of Ophthalmology, University of Arizona, Tucson, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Miller
authors.forename: H L
authors.initials: HL
authors.lastname: Hall
authors.forename: J E
authors.initials: JE
authors.lastname: Greivenkamp
authors.forename: D L
authors.initials: DL
authors.lastname: Guyton
mesh_terms: D000328:Adult; D000550:Amblyopia / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008027:Light; D008297:Male; D011680:Pupil / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013285:Strabismus / Q000175:diagnosis*; D014787:Vision Tests / Q000379:methods*