title: Foveal color and luminance sensitivity losses in glaucoma.
abstract: OBJECTIVE
  Losses in color vision sensitivity are noted in patients with glaucoma and these losses can occur before the onset of visual field defects in ocular hypertensive patients. The authors incorporate a technique that measures foveal luminance and isoluminant-color thresholds.
  
  
  METHODS
  This study included 31 patients with glaucoma, 10 patients suspected of having glaucoma, and 67 control subjects. The testing conditions measured thresholds under identical spatial and temporal conditions. Individual differences in luminosity between colors were controlled by presenting 16 different ratios of the three phosphors on a color monitor.
  
  
  RESULTS
  Relative to the control subjects, the patients with glaucoma showed a nonselective defect in both color and luminance sensitivity for red-green stimuli (P < .05), but a selective color defect for yellow-blue stimuli (P < .01). There were no statistically significant differences between patients suspected of having glaucoma and control subjects (P > 0.3).
  
  
  CONCLUSIONS
  If the isoluminant-color stimuli are detected by foveal P-ganglion cells, then these results suggest that glaucoma leads to a generalized decrease in P-ganglion cell sensitivity that is more pronounced for cells with an input from cones sensitive to short wavelengths.
authors.affiliation: Department of Psychology University of Washington (JPK), Seattle, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Kelly
authors.forename: S M
authors.initials: SM
authors.lastname: Fourman
authors.forename: L F
authors.initials: LF
authors.lastname: Jindra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003118:Color Perception / Q000502:physiology; D003119:Color Perception Tests / Q000379:methods; D003117:Color Vision Defects / Q000209:etiology / Q000503:physiopathology*; D015350:Contrast Sensitivity; D005074:Evoked Potentials, Visual; D005584:Fovea Centralis / Q000503:physiopathology*; D005901:Glaucoma / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007429:Intraocular Pressure; D008027:Light; D008875:Middle Aged; D012044:Regression Analysis