Smartphone-based Utility of the Vestibulo-ocular Reflex

Smartphone-based Utility of the Vestibulo-ocular Reflex: a Pilot Clinical Study

The goal of this observational study is to evaluate whether a novel smartphone-based (mHealth) application can accurately assess gaze stability and vestibulo-ocular reflex (VOR) function in adults with vestibular dysfunction. This pilot clinical ststudy includes adult participants with and without unilateral peripheral vestibular dysfunction to determine the feasibility of a mobile-based assessment of gaze stabilization.

The main questions it aims to answer are:

1. Can a prototype mHealth application accurately measure outcomes associated with standard dynamic gaze stabilization tests (e.g., static visual acuity, perception time, and maximal head velocity measurements)?
2. How well does a prototype mHealth application identify patients with unilateral peripheral vestibular dysfunction when compared to healthy volunteers?
3. Does a prototype mHealth application differ in identifying patients with unilateral peripheral vestibular dysfunction when compared to a commercially-available computer system that uses a gold-standard head-mounted sensor for gaze stabilization testing (GST)?

Participants will:

Perform the well-established GST protocol using a commercially-available computer system that uses a gold-standard head-mounted sensor Perform the well-established GST protocol a novel mHealth application

The following outcomes will be measured:

1. Standard visual acuity (SVA): The smallest readable target based on the user's best-aided vision
2. A perception time test (PTT): The shortest time a target can be accurately identified
3. A dynamic gaze stability test (GST): The maximal head velocity at which a patient can accurately identify the orientation of a presented visual target

This pilot clinical study will provide evidence to further support the use of mobile technology as a low-cost, accessible alternative for vestibular function assessment, particularly for patients in resource-limited settings.

Study Overview

• Status: Completed
• Conditions: Vestibular Function Tests; mHealth Application; Vestibular Function Disorder; Vestibulo-Ocular Reflex (VOR) Dysfunction

Detailed Description

Background & Rationale Vestibular dysfunction is a common condition affecting over a third of U.S. adults over the age of 40. It significantly increases the risk of falls, especially in those experiencing dizziness, where the odds of falling are increased 12-fold. Current best practices recommend vestibular rehabilitation, which includes gaze stability exercises designed to improve balance and reduce fall risk. However, many individuals, particularly those relying on home-based therapy or telehealth, face challenges in accessing objective assessments of their vestibulo-ocular reflex (VOR) contribution to gaze stabilization.

As telehealth has expanded rapidly in response to the COVID-19 pandemic, there is an increasing need for remote, real-time VOR teleassessments that can provide clinicians and patients with quantifiable, velocity-specific gaze stability data. While some computer-based remote VOR assessment tools exist, they often suffer from limitations in user satisfaction and accuracy. The Gaze Stabilization Test (GST), developed by Goebel et al., provides clinicians with velocity-specific data associated with the VOR's contribution to gaze stabilization. However, this test is typically performed in a clinical setting with specialized equipment, limiting access for many patients.

This pilot clinical study aims to validate a mHealth application (mVOR) prototype as a low-cost, accessible alternative to traditional VOR assessments. By leveraging the head- and eye-tracking capabilities of modern smartphones, this proof-of-concept prototype seeks to provide a novel, mobile-based framework for measuring visual acuity, head velocity, and gaze estimation in patients undergoing vestibular rehabilitation.

Study Objectives & Hypothesis

Primary Objectives:

To determine whether a prototype mHealth application can accurately assess static visual acuity, perception time, and maximal head velocity in individuals with unilateral peripheral vestibular dysfunction (UVD).

To compare the accuracy of the mVOR application against a commercially-available, in-office GST system that identifies patients with UVD.

Hypothesis:

The investigators hypothesize that by using the native head and eye-tracking capabilities of smartphones, one can obtain gaze stability (GST) measurements using a mobile platform that provides visual acuity and velocity-specific data comparable to a commercially-available, in-office GST system.

If validated, the mVOR could serve as an platform for effective, low-cost alternatives for telemonitoring vestibular function and enhancing remote rehabilitation programs for individuals with balance disorders.

Anticipated sample size: 50 (25 healthy volunteers and 25 patients with UVD)

Data Analysis

Within-group comparisons:

Paired t-tests or Wilcoxon Signed-Rank tests (depending on data distribution) will compare participants' GST and mVOR scores.

Between-group comparisons:

Independent t-tests or Mann-Whitney U tests will compare UVD vs. healthy volunteer group.

ROC Curve Analysis:

Receiver Operating Characteristic (ROC) curves will assess the accuracy of mVOR vs. computerized GST in distinguishing patients with UVD

Potential Benefits & Clinical Significance Increased Accessibility: The mVOR app provides an affordable, mobile alternative to in-office based GST system, expanding access to vestibular rehabilitation.

Telehealth & Home Monitoring: This study could support remote vestibular assessments, particularly for patients in rural or underserved communities.

Clinical Validation: If the mVOR performs comparably to the in-office based GST, it may be integrated into clinical practice as a validated tool for assessing vestibular function.

• Study Type: Observational
• Enrollment (Actual): 35

Contacts and Locations

Study Locations

• United States
  • Virginia
    • Charlottesville, Virginia, United States, 22903
      • University of Viginia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

A convenience sample of healthy volunteers employed by or affiliated with the University of Virginia; a convenience sample established patients of the University of Virginia health system who meet study criteria to be subjects in unilateral peripheral vestibular dysfunction (UVD) group

Description

Inclusion Criteria:

• Adults 18 years or older
• Able to provide informed consent
• Normal or corrected-to-normal vision (e.g., with glasses or contact lenses)
• Able to sit upright and follow instructions for the duration of the test (~2-3 hours)
• No known contraindications to head movement (e.g., musculoskeletal or neurological conditions that prevent safe head rotation)
• For vestibular dysfunction group: Participants must have a diagnosed vestibular disorder (e.g., vestibular hypofunction, vestibular neuritis, Meniere's disease, labyrinthitis, vestibular migraine, or post-concussive dizziness)
• For control group: Participants must be free from diagnosed vestibular disorders and report no history of balance issues, dizziness, or vertigo

Exclusion Criteria:

• Severe visual impairment that cannot be corrected with glasses or contact lenses
• Cognitive impairment or neurological conditions that could interfere with following instructions (e.g., moderate to severe dementia, uncontrolled seizures, severe traumatic brain injury)
• Severe musculoskeletal or orthopedic conditions affecting the neck or cervical spine that prevent safe head movement (e.g., cervical fusion, severe arthritis, neck instability)
• Acute illness or infection at the time of testing (e.g., flu, COVID-19, severe sinus infection that may impact vestibular function)
• Recent vestibular or neurological surgery (<6 months prior to study participation)
• Severe hearing loss that prevents understanding spoken instructions
• History of stroke or progressive neurological disorders affecting balance or gaze stability (e.g., Parkinson's disease, multiple sclerosis, ALS)
• Use of vestibular suppressants (e.g., meclizine, diazepam, scopolamine) within 24 hours of testing

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Unilateral vestibular dysfunction (UVD); This group includes with unilateral peripheral vestibular dysfunction identified via the Electronic Medical Record (EMR) and meet the following study criteria: Inclusion criteria: > 18 y/o; Willingness and ability to comply with scheduled visits and study procedures.; History of unilateral vestibular dysfunction (>49% asymmetry on bithermal binaural caloric testing) OR surgical ablation of vestibular end organ or nerve, such as via resection of unilateral vestibular schwannoma or labyrinthectomy) Exclusion criteria: No history of vestibular dysfunction; History of underlying cervical musculoskeletal disease that restricts the neck; History of cervical dysfunction that prevented them from moving their head, severe visual impairment or blind spots in the field, or central nervous system disorder
Healthy volunteers; This group includes with those without a history of unilateral peripheral dysfunction (UVD) and meet the following study criteria: Inclusion criteria: 18 y/o; Willingness and ability to comply with scheduled visits and study procedures Exclusion criteria: History of vestibular dysfunction; History of uncorrected vision; History of underlying cervical musculoskeletal disease that restricts the neck; History of cervical dysfunction that prevented them from moving their head, severe visual impairment or blind spots in the field, or central nervous system disorder

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accuracy of mVOR mHealth application system in assessing gaze stability	The mVOR application is expected to be able to distinguish the direction and peak velocity of head rotation as well as the consistency of gaze fixation. The primary outcome measure for this system is the "GST score", which is recorded as the maximum head velocity (in degrees/s) while maintaining visual acuity, a measure of gaze stabilization or dynamic visual. This clinical measure of vestibular function will be compared to a commercially available, in-office system (Bertex, Inc) that utilizes the GST protocol and a head-mounted sensory and is often used in Dizziness and Balance Centers around the world for vestibular rehabilitation. Primary variable analysis will include standard descriptive statistics and within-group and between in-group (UVD vs healthy volunteer) pairwise comparisons. ROC and AUC curves will be generated to evaluate the sensitivity and specificity of the mVOR application in distinguishing vestibular dysfunction from healthy controls.	Immediately after testing (single session, approximately 2-3 hour per participant)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of static visual acuity	The mVOR application is expected to be able to distinguish the direction and peak velocity of head rotation as well as the consistency of gaze fixation. In order to do this, per the gaze stabilization test (GST) protocol, the mHealth application must first determine a user's visual acuity with head kept still. This is called the static visual acuity (SVA) and is recorded in logMAR units. Primary variable analyses will include standard descriptive statistic and will also be compared to the same outcome measure obtained from a commercially available, in-office GST system.	Immediately during (2-3 hours) and following testing
Assessment of visual perception time	The mVOR application is expected to be able to distinguish the direction and peak velocity of head rotation as well as the consistency of gaze fixation. In order to do this, per the gaze stabilization test (GST) protocol, the mHealth application .(following determination of the static visual acuity [SVA]), must determine the minimum time at which a user can correctly identify a presented target with head kept still. This outcome measure is called the visual perception time (VPT) and is recorded in milliseconds (msec). Primary variable analyses will include standard descriptive statistic and will also be compared to the same outcome measure obtained from a commercially available, in-office GST system.	Immediately during (2-3 hours) and following testing

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Age	The following user/patient demographic will be obtained either prospectively throughout the clinical trial or retrospectively via the electronic medical record (EMR): The subject's age (in years) will be recorded. This will be analysed via standard descriptive statistics.	Prior to study enrollment and immediately after testing (single session, approximately 2-3 hour per participant)
Gender	The following user/patient demographic will be obtained either prospectively throughout the clinical trial or retrospectively via the electronic medical record (EMR): The subject's sex (male, female) will be recorded. This will be analysed via standard descriptive statistics.	Prior to study enrollment and immediately after testing (single session, approximately 2-3 hour per participant)
Dizziness Handicap Inventory (DHI) score	The following user/patient demographic will be obtained either prospectively throughout the clinical trial: Scores on the validated Dizziness Handicap Inventory (DHI) survey (scale 0-100) 16-34 Points (mild handicap), 36-52 Points (moderate handicap), and 54+ Points (severe handicap) This will be analysed via standard descriptive statistics.	Immediately after testing (single session, approximately 2-3 hour per participant)
Activities-specific Balance Confidence Scale (ABC Scale) score	The following user/patient demographic will be obtained prospectively throughout the clinical trial: Scores on the validated Activities-specific Balance Confidence Scale (ABC Scale) survey (scale 0-100%) 0% represents no confidence in performing an activity without losing balance and 100% indicates complete confidence This will be analysed via standard descriptive statistics	Immediately after testing (single session, approximately 2-3 hour per participant)
Duration from caloric testing	The following user/patient demographic will be obtained retrospectively via the electronic medical record (EMR): Duration from caloric testing (recorded in years), a part of the videonystagmography (VNG) test This will be analysed via standard descriptive statistics.	Prior to study enrollment and immediately after testing (single session, approximately 2-3 hour per participant)
Duration of known vestibular dysfunction	The following patient factor will be retrospectively via the electronic medical record (EMR): Duration of known vestibular dysfunction, recorded in years. This will be analyzed via standard descriptive statistics.	Prior to study enrollment and immediately after testing (single session, approximately 2-3 hour per participant)
Side of vestibular dysfunction	The following patient factor will be retrospectively via the electronic medical record (EMR): Side of known vestibular dysfunction, recorded as left or right. This will be analyzed via standard descriptive statistics.	Prior to study enrollment and immediately after testing (single session, approximately 2-3 hour per participant)
Duration of vestibular physical therapy	The following patient factor will be retrospectively via the electronic medical record (EMR): Duration of vestibular physical therapy, recorded in years This will be analyzed via standard descriptive statistics.	Prior to study enrollment and immediately after testing (single session, approximately 2-3 hour per participant)

Collaborators and Investigators

• Sponsor: University of Virginia
• Collaborators: National Institute on Deafness and Other Communication Disorders (NIDCD)
• Investigators: Principal Investigator: Adam Thompson-Harvey, MD, University of Virginia; Principal Investigator: Bradley Kesser, MD, University of Virginia

Publications and helpful links

General Publications

• Jacobson GP, Newman CW. The development of the Dizziness Handicap Inventory. Arch Otolaryngol Head Neck Surg. 1990 Apr;116(4):424-7. doi: 10.1001/archotol.1990.01870040046011.
• Powell LE, Myers AM. The Activities-specific Balance Confidence (ABC) Scale. J Gerontol A Biol Sci Med Sci. 1995 Jan;50A(1):M28-34. doi: 10.1093/gerona/50a.1.m28.
• Hall CD, Heusel-Gillig L, Tusa RJ, Herdman SJ. Efficacy of gaze stability exercises in older adults with dizziness. J Neurol Phys Ther. 2010 Jun;34(2):64-9. doi: 10.1097/NPT.0b013e3181dde6d8.
• Hall CD, Herdman SJ, Whitney SL, Cass SP, Clendaniel RA, Fife TD, Furman JM, Getchius TS, Goebel JA, Shepard NT, Woodhouse SN. Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Evidence-Based Clinical Practice Guideline: FROM THE AMERICAN PHYSICAL THERAPY ASSOCIATION NEUROLOGY SECTION. J Neurol Phys Ther. 2016 Apr;40(2):124-55. doi: 10.1097/NPT.0000000000000120.
• Huang K, Sparto PJ, Kiesler S, Siewiorek DP, Smailagic A. iPod-based in-home system for monitoring gaze-stabilization exercise compliance of individuals with vestibular hypofunction. J Neuroeng Rehabil. 2014 Apr 21;11:69. doi: 10.1186/1743-0003-11-69.
• Chen PY, Hsieh WL, Wei SH, Kao CL. Interactive wiimote gaze stabilization exercise training system for patients with vestibular hypofunction. J Neuroeng Rehabil. 2012 Oct 9;9:77. doi: 10.1186/1743-0003-9-77.
• Goebel JA, Tungsiripat N, Sinks B, Carmody J. Gaze stabilization test: a new clinical test of unilateral vestibular dysfunction. Otol Neurotol. 2007 Jan;28(1):68-73. doi: 10.1097/01.mao.0000244351.42201.a7.
• Agrawal Y, Carey JP, Della Santina CC, Schubert MC, Minor LB. Disorders of balance and vestibular function in US adults: data from the National Health and Nutrition Examination Survey, 2001-2004. Arch Intern Med. 2009 May 25;169(10):938-44. doi: 10.1001/archinternmed.2009.66.

Study record dates

Study Major Dates

• Study Start (Actual): April 21, 2025
• Primary Completion (Actual): July 30, 2025
• Study Completion (Actual): July 30, 2025

Study Registration Dates

• First Submitted: February 12, 2025
• First Submitted That Met QC Criteria: March 2, 2025
• First Posted (Actual): March 4, 2025

Study Record Updates

• Last Update Posted (Estimated): October 23, 2025
• Last Update Submitted That Met QC Criteria: October 21, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Vestibular Dysfunction; Gaze Stabilization Test (GST); Vestibulo-Ocular Reflex (VOR); mHealth Vestibular Testing
• Additional Relevant MeSH Terms: Otorhinolaryngologic Diseases; Ear Diseases; Labyrinth Diseases; Vestibular Diseases
• Other Study ID Numbers: HSR230265; 1R41DC022209-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

De-identified individual participant data (IPD) will be shared with other researchers upon request. The following data will be made available:

Demographic Information (age, gender, group allocation - control vs. vestibular dysfunction) Outcome Measures (static visual acuity in logMAR, perception time in ms, maximum head velocity in deg/s) Comparison Data (mVOR mHealth application GST results vs. in-office computerized GST results) Statistical Analysis Outputs (correlation coefficients, ROC curve data, Bland-Altman plots) Data will be shared in compliance with applicable privacy laws and regulations, ensuring that all information remains de-identified and anonymized. Requests for data access will be reviewed by the study investigators and granted for research purposes related to vestibular assessment, gaze stabilization, and telehealth applications.

Researchers interested in accessing the data may contact the principal investigator.

IPD Sharing Time Frame

Start Date: Data and supporting information will be available six months after study completion to allow for initial publication of findings.

End Date: Data will remain available for at least five years post-publication or as required by funders and institutional policies.

IPD Sharing Access Criteria

Who can access the data?

Qualified researchers, academic institutions, and healthcare professionals conducting research related to vestibular function, gaze stabilization, or telehealth applications.

What data will be accessible?

De-identified individual participant data (IPD), including demographic variables, study outcomes, and comparison data between mVOR mHealth application and in-office computerized GST.

Supporting documents such as the study protocol, statistical analysis plan (SAP), clinical study report (CSR), and analytic code for reproducing study results.

How to access the data?

Researchers must submit a formal data request to the principal investigator. Requests will be reviewed on a case-by-case basis to ensure appropriate research use.

Upon approval, access to datasets and supporting information will be provided through a secure data-sharing repository or via institutional agreements.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes