title: Anomaloscope examination: scotopization (the luminance fall).
abstract: OBJECTIVE
  The evaluation of a criterion for the detection of pathologic scotopization in routine anomaloscope examination.
  
  
  METHODS
  Fifty congenital protan subjects, 50 congenital deutan subjects, 30 autosomal recessive congenital achromats, and 25 (44 eyes) acquired type I red-green defective subjects were selected. The anomaloscope examination was according to the Linksz procedure. The luminance fall was calculated as the slope quotient SQ: Y units luminance fall per X units width of the matching range.
  
  
  RESULTS
  The mean SQ was -0.01 for congenital deutan subjects, -0.40 for congenital protan subjects and -1.30 for congenital achromats. There was no overlap between the three groups. Pathologic scotopization was found in 98% of the eyes presenting with an acquired type I colour vision defect.
  
  
  CONCLUSIONS
  Calculation of the slope quotient SQ is helpful for the detection of pathologic scotopization in acquired colour vision deficiency.
authors.affiliation: Department of Ophthalmology, St. Radboudziekenhuis, Nijmegen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Pinckers
mesh_terms: D003117:Color Vision Defects / Q000151:congenital / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008027:Light; D009885:Ophthalmology / Q000295:instrumentation; D014785:Vision, Ocular