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Recovery of Visual Acuity in People With Vestibular Deficits

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00411216
First Posted: December 13, 2006
Last Update Posted: August 7, 2015
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborator:
National Institute on Deafness and Other Communication Disorders (NIDCD)
Information provided by (Responsible Party):
Susan Herdman, Emory University
December 12, 2006
December 13, 2006
December 20, 2013
July 21, 2014
August 7, 2015
August 2000
December 2004   (Final data collection date for primary outcome measure)
  • Change in Visual Acuity During Head Movement From Baseline to Discharge [ Time Frame: pre-intervention and at discharge ]

    visual acuity is measured using a computerized system first with the head stationary and then with the head moving in yaw plane. Head velocity is measured using a rate sensor and optotype is displayed only when head velocity is between 120 and 180 degrees per second.

    The change in visual acuity was calculated from subtracting the discharge measurement from the baseline measurement (pre-intervention).

  • Subjective Complaints: (All Pre- and Post-intervention): [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ]
    questionnaire
Visual acuity during head movement: Computerized Dynamic Visual Acuity test; measurement taken before intervention, at 2 and 4 weeks during intervention at at end of intervention
Complete list of historical versions of study NCT00411216 on ClinicalTrials.gov Archive Site
  • Disability Scale [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ]
    questionnaire
  • Activities Specific Balance Confidence Scale [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ]
    questionnaire
  • Symptoms Intensity for Dizziness, Oscillopsia, Disequilibrium [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ]
    visual analoque scales
  • Balance and Gait [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ]
    gait speed
  • Fall Risk (Dynamic Gait Index) [ Time Frame: pre-intervention, 2 weeks, 4 weeks and at discharge ]
    performance test
  • Eye Movements: Scleral Search Coil [ Time Frame: pre- and post-treatment ]
    eye movements are measured by having the participant sit within an electromagnetic field while wearing a scleral coil (like a contact lens but only in contact with the sclea, not the cornea); te coil moves with eye movement and distorts the electrimagnetic field
  • Vestibular Function: Caloric Test (Pre-intervention); Rotary Chair Test (Pre- and Post-intervention)
  • Subjective complaints: (all pre- and post-intervention):
  • Disability Scale
  • Activities Specific Balance Confidence Scale
  • Symptoms Intensity for Dizziness, Oscillopsia, Disequilibrium
  • Balance and Gait
  • Fall Risk (Dynamic Gait Index)
  • Eye Movements: Scleral Search Coil
Not Provided
Not Provided
 
Recovery of Visual Acuity in People With Vestibular Deficits
Recovery of Visual Acuity in Vestibular Deficits
The purpose of this study is to determine whether exercises relieve the symptoms of dizziness and imbalance in people with vestibular deficits and improves the ability to see clearly during head movements. We hypothesize that the performance of specific adaptation and substitution exercises will result in an improvement in visual acuity during head movements while those patients performing placebo exercises will show no improvement.

Decrements in visual acuity during head movement in patients with vestibular hypofunction are potentially serious problems. This deficit could contribute to decreased activity level, avoidance of driving with resultant diminished independence and, ultimately, limited social interactions and increased isolation. Oscillopsia occurs because of inadequate vestibulo-ocular reflex (VOR) gain and suggests that compensation for the vestibular loss has not occurred. The purpose of this study was to examine the effect of an exercise intervention on visual acuity during head movement in patients with unilateral and bilateral vestibular hypofunction. We hypothesized that 1) patients performing vestibular exercises would have improved visual acuity during head movement compared to patients performing placebo exercises; 2) there would be no correlation between dynamic visual acuity (DVA) and the patients' subjective complaints of oscillopsia; and 3) improvement in DVA would be reflected by changes in residual vestibular function as indicated by an increase in VOR gain.

Patients are assigned randomly to either the vestibular exercise or placebo exercise group. The randomization schedule is generated using a computer program for 2-sample randomization. The sequence was not concealed from the investigator who obtained consent from the subjects and supervised the exercises (SJH). The group assignment (vestibular exercise or placebo exercise) was concealed from the participants and from the investigator who performed the outcome measures.

The vestibular exercise group practiced exercises that consisted of adaptation exercises and eye-head exercises to targets (Table 1), which were designed to improve gaze stability 16. They also performed gait and balance exercises. The placebo exercise group performed exercises designed to be 'vestibular-neutral'.

Interventional
Not Provided
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Treatment
  • Vestibular Neuronitis
  • Vestibular Neuronitis, Bilateral
  • Vestibular Schwannoma
  • Other: Control exercises
    saccadic eye movements against a plain background; no head movements
  • Other: gaze stabilization exercises
    adaptation and substitutin exercises encorporating retinal lsip and head movements
  • Experimental: exercises for gaze stabilization
    Experimental group performed vestibular adaptation and substitution exercises
    Intervention: Other: gaze stabilization exercises
  • Placebo Comparator: Control exercises
    Saccadic eye movements against a Ganzfeld to prevent retinal slip error signal; no head movements
    Intervention: Other: Control exercises

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
23
December 2004
December 2004   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Patient had to have either a unilateral vestibular or bilateral vestibular hypofunction defined as follows: Unilateral vestibular deficits were defined by a > 25% difference in slow phase eye velocity between right and left sides on either the caloric or rotary chair test. Bilateral vestibular deficits were defined included refixation saccades made in response to unpredictable head thrusts to the right and left, a gain < .1 on rotary chair step test and a peak slow phase eye movement of <5 degrees/sec during irrigation of each ear on bithermal water caloric testing
  • Healthy subjects with normal vestibular function test results
  • must be able to complete DVA test

Exclusion Criteria:

  • Patients with central lesions will be omitted from the study because vestibular adaptation or other compensatory mechanisms may be compromised and
  • Patients with visual acuity when the head is stationary of 20/60 or worse.
  • Patients on medication that suppress or facilitate vestibular function will not be excluded from the study but data will be analyzed to assess the effect of medication.
  • Patient who do not understand the purpose of the study and what it involves
Sexes Eligible for Study: All
18 Years to 80 Years   (Adult, Senior)
Yes
Contact information is only displayed when the study is recruiting subjects
United States
 
 
NCT00411216
IRB00000336
R01DC003196 ( U.S. NIH Grant/Contract )
No
Not Provided
Not Provided
Susan Herdman, Emory University
Emory University
National Institute on Deafness and Other Communication Disorders (NIDCD)
Principal Investigator: Susan J Herdman, PhD Emory University
Emory University
July 2015

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP