title: Visual impairment in Parkinson's disease: deficits in orientation and motion discrimination.
abstract: OBJECTIVE
  In order to obtain a better understanding of the pathophysiology of visual impairment in Parkinson's disease (PD), orientation and motion discrimination were investigated in PD patients.
  
  
  METHODS
  Orientation and motion discrimination thresholds were assessed psychophysically in PD patients with normal cognition (N = 11) and compared to results for age-matched controls (N = 22).
  
  
  RESULTS
  PD patients exhibited a significant deficit in orientation discrimination for horizontal but not for vertical gratings. Also, motion discrimination thresholds were elevated significantly in PD patients. No significant correlations were found between motion and orientation discrimination thresholds.
  
  
  CONCLUSIONS
  Our results indicate that PD patients exhibit significant visual dysfunction in the absence of cognitive impairment supporting the contention that neural dysfunction in PD is more generalized than previously realized. The results provide further evidence of an orientation selective visual deficit in PD and show that the ability to discriminate global motion is also attenuated in PD.
authors.affiliation: School of Optometry, University of Montreal, Quebec.
authors.forename: G L
authors.initials: GL
authors.lastname: Trick
authors.forename: B
authors.initials: B
authors.lastname: Kaskie
authors.forename: S B
authors.initials: SB
authors.lastname: Steinman
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D011601:Psychophysics; D012684:Sensory Thresholds; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology*