title: Visual acuity while walking and oscillopsia severity in healthy subjects and patients with unilateral and bilateral vestibular function loss.
abstract: OBJECTIVE
  To assess visual acuity (VA) while the patient is walking and to evaluate oscillopsia severity in patients with bilateral vestibulopathy (BV) and in patients with unilateral vestibular loss (UVL).
  
  
  METHODS
  Prospective study with a group of patients with BV, a group of patients with UVL, and a control group of healthy subjects.
  
  
  METHODS
  Tertiary academic center.
  
  
  METHODS
  Thirty seven patients with BV(age range, 29-80 years), 11 patients with UVL (age range, 48-75 years), and 57 healthy subjects (age range 20-77 years).
  
  
  METHODS
  Computation of the difference between the VA measured in static conditions and in dynamic conditions while walking on a treadmill at 2, 4, and 6 km/h. Oscillopsia severity was assessed with a questionnaire that we developed.
  
  
  METHODS
  Differences in VA at 2, 4, and 6 km/h and oscillopsia severity score.
  
  
  RESULTS
  As a group, patients with BV showed a significant increase of the VA differences compared with healthy subjects (P < .001) and patients with UVL (P < .001) for all 3 walking velocities. Normality thresholds were defined as healthy subjects' 95% CI. Sensitivity of the test was 97% for discriminating patients with BV. Moderate to extreme oscillopsia severity was found in 81% of patients with BV and in 9% of patients with UVL. Differences in VA did not correlate with oscillopsia severity scores in patients with BV (P > .05 for all comparisons).
  
  
  CONCLUSIONS
  We designed a highly sensitive, simple, cost-effective protocol to assess dynamic VA under physiologic conditions and a questionnaire to determine oscillopsia severity. Both tools could be used for the evaluation of new treatments for BV and patients with UVL.
authors.affiliation: Division of Balance Disorders, Department of Otorhinolaryngology, University Hospital Maastricht, Maastricht, The Netherlands. Nils.Guinand@hcuge.ch
authors.forename: Nils
authors.initials: N
authors.lastname: Guinand
authors.forename: Mark
authors.initials: M
authors.lastname: Pijnenburg
authors.forename: Maurice
authors.initials: M
authors.lastname: Janssen
authors.forename: Herman
authors.initials: H
authors.lastname: Kingma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000503:physiopathology*; D011446:Prospective Studies; D012044:Regression Analysis; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D015837:Vestibular Diseases / Q000503:physiopathology*; D014724:Vestibular Function Tests; D014792:Visual Acuity; D016138:Walking / Q000502:physiology*