title: Contrast sensitivity and visual hallucinations in patients referred to a low vision rehabilitation clinic.
abstract: OBJECTIVE
  To examine the association of reported visual hallucinations and measured visual parameters in adult patients referred for low vision rehabilitation.
  
  
  METHODS
  All patients (N = 225) referred to a low vision rehabilitation clinic for a calendar year were asked a standardised question about symptoms of formed visual hallucinations. Best corrected visual acuity and contrast sensitivity using the Pelli-Robson chart were measured. We conducted multiple logistic regression analysis of the association between visual hallucinations and visual parameters.
  
  
  RESULTS
  Of the total cohort, 78 (35%) reported visual hallucinations. Visual acuity and contrast sensitivity were considered in four quartiles. In multiple logistic regression controlling for contrast sensitivity, age, gender, report of depression and independence, measured acuity in each of the poorer three categories (compared to the best) was not associated with reported hallucinations. Contrast sensitivity in the three poorer quartiles (compared to the best) was strongly associated with the report of hallucinations (OR 4.1, CI 1.1, 15.9; OR 10.5, CI 2.6, 42.1; OR 28.1, CI 5.6, 140.9) after controlling for acuity, age, sex, depression and independence.
  
  
  CONCLUSIONS
  Lowest contrast sensitivity was the strongest predictor of reported hallucinations after adjusting for visual acuity.
authors.affiliation: Vision Rehabilitation Center, Massachusetts Eye and Ear Infirmary, Harvard Department of Ophthalmology, Boston, Massachusetts 02114, USA. Marylou_jackson@meei.harvard.edu
authors.forename: M L
authors.initials: ML
authors.lastname: Jackson
authors.forename: K
authors.initials: K
authors.lastname: Bassett
authors.forename: P V
authors.initials: PV
authors.lastname: Nirmalan
authors.forename: E C
authors.initials: EC
authors.lastname: Sayre
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015350:Contrast Sensitivity; D005260:Female; D006212:Hallucinations / Q000209:etiology*; D006801:Humans; D008297:Male; D012047:Rehabilitation Centers; D014787:Vision Tests / Q000379:methods; D015354:Vision, Low / Q000523:psychology / Q000534:rehabilitation*; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000523:psychology / Q000534:rehabilitation