Recovery of Visual Acuity in People With Vestibular Deficits

Vestibular Schwannoma Clinical Trial

Official title:

Recovery of Visual Acuity in Vestibular Deficits

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00411216
• Other study ID #: IRB00000336
• Secondary ID: R01DC003196
• Status: Completed
• Phase: N/A
• First received: December 12, 2006
• Last updated: July 16, 2015
• Start date: August 2000
• Est. completion date: December 2004

Study information

• Verified date: July 2015
• Source: Emory University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

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.

Description:

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'.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 23
• Est. completion date: December 2004
• Est. primary completion date: December 2004
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 80 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Neuroma, Acoustic
• Vestibular Neuronitis
• Vestibular Neuronitis, Bilateral
• Vestibular Schwannoma

Intervention

Other:
• Control exercises
saccadic eye movements against a plain background; no head movements
• gaze stabilization exercises
adaptation and substitutin exercises encorporating retinal lsip and head movements

Locations

Country	Name	City	State
United States	Center for Rehabilitation Medicine, Emory University	Atlanta	Georgia

Sponsors (2)

Lead Sponsor	Collaborator
Emory University	National Institute on Deafness and Other Communication Disorders (NIDCD)

Country where clinical trial is conducted

United States, 

References & Publications (7)

Hall CD, Schubert MC, Herdman SJ. Prediction of fall risk reduction as measured by dynamic gait index in individuals with unilateral vestibular hypofunction. Otol Neurotol. 2004 Sep;25(5):746-51. — View Citation

Herdman SJ, Schubert MC, Das VE, Tusa RJ. Recovery of dynamic visual acuity in unilateral vestibular hypofunction. Arch Otolaryngol Head Neck Surg. 2003 Aug;129(8):819-24. — View Citation

Herdman SJ, Schubert MC, Tusa RJ. Role of central preprogramming in dynamic visual acuity with vestibular loss. Arch Otolaryngol Head Neck Surg. 2001 Oct;127(10):1205-10. — View Citation

Herdman SJ, Tusa RJ, Blatt P, Suzuki A, Venuto PJ, Roberts D. Computerized dynamic visual acuity test in the assessment of vestibular deficits. Am J Otol. 1998 Nov;19(6):790-6. — View Citation

Schubert MC, Das V, Tusa RJ, Herdman SJ. Cervico-ocular reflex in normal subjects and patients with unilateral vestibular hypofunction. Otol Neurotol. 2004 Jan;25(1):65-71. — View Citation

Schubert MC, Herdman SJ, Tusa RJ. Functional measure of gaze stability in patients with vestibular hypofunction. Ann N Y Acad Sci. 2001 Oct;942:490-1. — View Citation

Schubert MC, Herdman SJ, Tusa RJ. Vertical dynamic visual acuity in normal subjects and patients with vestibular hypofunction. Otol Neurotol. 2002 May;23(3):372-7. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Visual Acuity During Head Movement From Baseline to 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).	pre-intervention and at discharge	No
Primary	Subjective Complaints: (All Pre- and Post-intervention):	questionnaire	pre-intervention, 2 weeks, 4 weeks and at discharge	No
Secondary	Disability Scale	questionnaire	pre-intervention, 2 weeks, 4 weeks and at discharge	No
Secondary	Activities Specific Balance Confidence Scale	questionnaire	pre-intervention, 2 weeks, 4 weeks and at discharge	No
Secondary	Symptoms Intensity for Dizziness, Oscillopsia, Disequilibrium	visual analoque scales	pre-intervention, 2 weeks, 4 weeks and at discharge	No
Secondary	Balance and Gait	gait speed	pre-intervention, 2 weeks, 4 weeks and at discharge	Yes
Secondary	Fall Risk (Dynamic Gait Index)	performance test	pre-intervention, 2 weeks, 4 weeks and at discharge	Yes
Secondary	Eye Movements: Scleral Search Coil	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	pre- and post-treatment	Yes