Recruiting

VOR Adaptation

Sponsor:

Emory University

Code:

NCT07380256

Conditions

Vestibular Hypofunction

Binocular Vision Abnormalities

Reduced Vision

Eligibility Criteria

Sex: All

Age: 18 - 60

Healthy Volunteers: Not accepted

Interventions

StableEyes: Incremental Vestibulo-Ocular Reflex Adaptation (IVA)

Study Details

Brief summary:

The goal of this study is to learn whether a balance-training exercise called incremental vestibulo-ocular reflex adaptation (IVA) is safe and effective for adults with vision impairments, with or without additional vestibular (inner-ear balance) problems.

The main questions it aims to answer are:

  • Does IVA cause only mild, temporary symptoms and no serious adverse events?
  • Does IVA improve eye-movement reflexes, balance, and walking, and do these improvements differ between people with vision problems alone and those with both vision and vestibular impairments?

Researchers will compare adults with vision impairment only to adults who have both vision and vestibular impairments to see whether the groups respond differently to IVA.

Participants will:

  • Complete symptom ratings before and after IVA
  • Undergo tests of vestibular reflexes (e.g., VOR gain)
  • Complete balance and walking assessments

Conditions

Vestibular Hypofunction

Binocular Vision Abnormalities

Reduced Vision

Study ID

NCT07380256

Start date

Feb 4, 2026

Status verified date

Apr, 2026

Completion date

Dec, 2029

Anticipated

Primary completion date

Dec, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 60

Healthy Volunteers: Not accepted

Inclusion Criteria:

For All Participants (All Groups)

  • Age 18 to 60 years
  • Able to provide informed consent

Group-Specific Inclusion Criteria:

  • Group 1: Abnormal Uncorrected Static Visual Acuity (No Vestibular Hypofunction) Normal peripheral vestibular function
  • Group 2: Abnormal Uncorrected Static Visual Acuity + peripheral Vestibular Hypofunction
  • Group 3: Binocular Vision Abnormalities (No Vestibular Hypofunction) Normal peripheral vestibular function
  • Group 4: Binocular Vision Abnormalities + peripheral Vestibular Hypofunction

Individuals who have abnormal static visual acuity, a binocular vision abnormality (ocular misalignment, convergence insufficiency), and vestibular loss will be assigned to Group 4.

The following definitions will be used when determining group placement:

  • Abnormal Static Visual Acuity: Uncorrected visual acuity (head is still) ≥0.30 logMAR in both eyes.
  • Unilateral Vestibular Hypofunction: 60 ms VOR gain <0.80 unilaterally for the lateral semicircular canal.
  • Bilateral Vestibular Hypofunction: 60 ms VOR gain <0.80 bilaterally for the lateral semicircular canals.
  • Normal Vestibular Function: 60 ms VOR gain of 0.80 to 1.20 bilaterally for the lateral semicircular canals.
  • Convergence Insufficiency: ≥6 cm near point of convergence.
  • Ocular Misalignment: ≥4 prism diopters of manifest deviation of the eyes (tropia) on cover/uncover testing.

Exclusion Criteria:

  • Diagnosis of fluctuating vestibular disorders (e.g., benign paroxysmal positional vertigo)
  • Neurologic conditions (e.g., multiple sclerosis), dementia,
  • Alcohol or drug abuse,
  • A major psychiatric disorder (e.g., schizophrenia),
  • Pain that limits cervical spine range of motion by >50% or that results in an -altered gait pattern.

Study Design

Enrollment

100 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Group 1: Abnormal Uncorrected Static Visual Acuity (No Vestibular Hypofunction)

Adults with abnormal uncorrected distance visual acuity and normal vestibular function.

This group will be part of Experiment 1. This experiment studies people whose main visual problem is reduced uncorrected distance visual acuity (i.e., blurry vision without glasses/contacts).

Experiment 1 tests the effect of blurry vision on VOR adaptation

experimental: Group 2: Abnormal Uncorrected Static Visual Acuity + Vestibular Hypofunction

Adults with abnormal uncorrected distance visual acuity and unilateral vestibular hypofunction.

This group will be part of Experiment 1. This experiment studies people whose main visual problem is reduced uncorrected distance visual acuity (i.e., blurry vision without glasses/contacts).

Experiment 1 tests the effect of blurry vision on VOR adaptation

experimental: Group 3: Binocular Vision Abnormalities (No Vestibular Hypofunction)

Adults with binocular vision abnormalities (e.g., convergence insufficiency, ocular misalignment) and normal vestibular function.

This group will be part of Experiment 2. This experiment studies people whose main visual problem is how the two eyes work together (e.g., convergence insufficiency, ocular misalignment).

Experiment 2 tests the effect of binocular vision dysfunction on VOR adaptation

experimental: Group 4: Binocular Vision Abnormalities + Vestibular Hypofunction

Adults with binocular vision abnormalities and unilateral vestibular hypofunction.

This group will be part of Experiment 2. This experiment studies people whose main visual problem is how the two eyes work together (e.g., convergence insufficiency, ocular misalignment).

Experiment 2 tests the effect of binocular vision dysfunction on VOR adaptation

Interventions

StableEyes: Incremental Vestibulo-Ocular Reflex Adaptation (IVA)

IVA is delivered using the StableEyes device, which includes a lightweight head-mounted unit with inertial sensors and a micromirror that controls the position of a low-power laser target projected onto a wall. The device adjusts the target's movement based on the participant's head velocity to create a controlled visual error signal that induces vestibulo-ocular reflex (VOR) adaptation. During each session, participants sit about one meter from a blank wall and perform rapid, self-generated head impulses while visually tracking the moving laser target. The target appears at neutral, moves at a fraction of head velocity during each impulse, and briefly disappears before reappearing at center. Each session lasts 15 minutes and includes roughly 150 head impulses in the horizontal or vertical plane. The procedure has been well-tolerated in prior studies with no reported adverse events.

Primary outcome measure

  • Change in Vestibulo-Ocular Reflex (VOR) Gain [ Time Frame: Baseline (visit 1) (before and after after IVA intervention), Visit 2 (2-10 days from baseline) (before and after IVA intervention) ]

Central Contacts and Locations

Central contacts

Colin R Grove, PT,DPT,PhD

(404) 712-8685colin.riess.grove@emory.edu

Hannah M Morris

hannah.m.morris@emory.edu

Locations

Dizziness and Balance Center

Recruiting

Atlanta, Georgia, United States, 30329

Contacts

Colin Grove, PT, DPT, PhD

404-712-8685colin.r.grove@emory.edu

Principal Investigator:

David Sandlin, MD

More Information

Sponsor

Emory University

Last update posted

Apr 17, 2026

Last verified

Apr, 2026

Keywords

  • vestibulo-ocular reflex
  • incremental vestibulo-ocular reflex adaptation
  • abnormal uncorrected static visual acuity
  • Gait Disorientation Test
  • video head impulse test
  • vertical and torsional alignment nulling
  • dynamic visual acuity test
  • modified Clinical Test of Sensory Interaction in Balance

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Emory University on 2026-04-17.