Intermittent ExotropiaVT-IXTNCT04487249
Trial of Vision Therapy for Intermittent Exotropia
A study testing Vision Therapy in people with Intermittent Exotropia, run by Southern California College of Optometry at Marshall B. Ketchum University at 6 sites in United States.
Trial summary
The main objective of this randomized trial comparing vision therapy to observation is to determine the short-term effectiveness of vision therapy on distance intermittent exotropia control. The results will help determine whether to proceed to a full-scale, long-term randomized trial. Read more about this study
- Who is it for?
- Ages 8 to 16 years
- Conditions the study is for
- Intermittent Exotropia
- What is being tested?
- Vision Therapy
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 47 participants
- Where
- 6 sitesUnited States
- Study dates
- 1 Oct 2021to 30 Apr 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 8 to 16 years
- All sexes
- No healthy volunteers
- Child
Major Inclusion Criteria-
- Age 8 - 16 years
- Intermittent exotropia meeting all of the following:
- Distance exodeviation of 15∆ to 35∆ by prism alternating cover test (PACT)
- IXT, exophoria, or orthophoria at near
- Near exodeviation that does not exceed the distance exodeviation by more than 10∆
- Mean distance control score of 2 points or more with at least one measure being 3 points or higher
- Mean near control score less than 5 points
- Random dot stereopsis of 200" or better on Preschool Randot Stereotest
- Willingness to accept randomization and no plan to relocate in the next 6 months
Major Exclusion Criteria-
- Treatment for IXT or amblyopia (other than refractive correction) within 3 months prior to enrollment
- Office-based vision therapy for IXT within 6 months prior to enrollment
- Prior office-based vision therapy for IXT of ≥10 sessions
- Prior strabismus, intraocular, or refractive surgery (including BOTOX injection)
Trial locations and contacts
6 sites in 1 country.
6 sites in 1 country
United States6 sites
University of Alabama in Birmingham
Birmingham, Alabama, 35294
Ohio State University
Columbus, Ohio, 43210
Southern California College of Optometry at Marshall B. Ketchum University
Fullerton, California, 92831
Southern College of Optometry
Memphis, Tennessee, 38104
Salus University
Philadelphia, Pennsylvania, 19141
Stanford University
Stanford, California, 94305
About this study
Official title: A Pilot Randomized Trial Evaluating Short-Term Effectiveness of Vision Therapy in Children With Intermittent Exotropia
The main objective of this randomized trial comparing vision therapy to observation is to determine the short-term effectiveness of vision therapy on distance intermittent exotropia control. The results will help determine whether to proceed to a full-scale, long-term randomized trial.
Read the detailed description
Vision therapy (VT) is a commonly prescribed treatment for children with intermittent exotropia (IXT). The effectiveness of VT as a treatment modality for children with IXT is unknown because previous studies have largely limited observational or retrospective case series without comparison groups. The objective of this multi-centered pilot randomized trial of VT for IXT compared to observation is to 1) determine the short-term effectiveness of VT on distance intermittent exotropia and 2) determine the feasibility of recruitment and retention of children aged 8 to 16 years old with IXT to participate in a randomized trial of 20 weeks of in-office VT. The results of this trial will provide the needed information to plan and conduct a large-scale randomized trial to determine short-term and long-term effectiveness of VT for IXT in children, with the full-scale randomized trial helping to fill in the gaps in scientific knowledge concerning VT as a treatment for IXT.
- Conditions
- Intermittent Exotropia
- Being tested
- Vision Therapy
- Keywords
- Intermittent Exotropia, Vision Therapy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vision TherapyOther
Also called Orthoptics
20 consecutive weeks of office-based vision therapy with home therapy that aim to improve the participant's vergence skills, accommodative skills, and sensory fusion.
| Study group | Role | What they receive |
|---|---|---|
| Vision Therapy | Experimental | Participants will receive 20 consecutive weeks of office-based vision therapy with home therapy. Receives: Other: Vision Therapy |
| Observation | No intervention | Participants will receive no treatment for IXT is received during the study unless one of the deterioration criteria is met. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean Distance Control Score
The primary analysis will be an intent-to-treat comparison of mean distance control score, determine by the intermittent exotropia office control scale, at outcome using an analysis of covariance model, which will adjust for baseline distance control. The intermittent exotropia office control scale grades the control on a scale of 0 (best control; phoria) to 5 (worst control; constant exotropia).
Measured: 21 weeks
Secondary outcomes (2)
No Spontaneous Tropia
The proportion of participants with no spontaneous tropia at outcome will be compared between treatment groups.No spontaneous tropia is defined as control score of 2 or less on all three assessments of control at distance and near and no exotropia lasting more than 5 seconds throughout the examination.
Measured: 21 weeks
Change in Distance Control
The proportion of participants with >= 1 point change in control and >= 2 points change in control will be compared between treatment groups.
Measured: 21 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jul 2020
- Study start1 Oct 2021
- Primary completion30 Apr 2026
- Study completion30 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intermittent ExotropiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 47 participants (actual)
Sponsor and investigators
- Lead sponsor
- Southern California College of Optometry at Marshall B. Ketchum University
- Sponsor type
- University, hospital or other
- Collaborators
- Stanford University, Ohio State University, Salus University, University of Alabama at Birmingham, Southern College of Optometry, Case Western Reserve University, American Academy of Optometry, University of Houston
- Responsible party
- Sponsor
- Investigators
- Angela Chen, OD, MS, Study chair, Southern California College of Optometry at Marshall B. Ketchum University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04487249
- Sponsor's protocol ID
- 20-08
- Acronym
- VT-IXT
- Status last verified
- May 2026
- First submitted
- 17 Jul 2020
- Last updated
- 3 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Randomized Trial Evaluating Short-Term Effectiveness of Vision Therapy in Children With Intermittent Exotropia
- ClinicalTrials.gov ID
- NCT04487249
- Acronym / sponsor ID
- VT-IXT / 20-08
- Conditions
- Intermittent Exotropia
- Keywords
- Intermittent Exotropia, Vision Therapy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 47 participants (actual)
- Lead sponsor
- Southern California College of Optometry at Marshall B. Ketchum UniversityUniversity, hospital or other
- Collaborators
- Stanford University, Ohio State University, Salus University, University of Alabama at Birmingham, Southern College of Optometry, Case Western Reserve University, American Academy of Optometry, University of Houston
- Study start
- 1 Oct 2021 (actual)
- Primary completion
- 30 Apr 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 27 Jul 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The main objective of this randomized trial comparing vision therapy to observation is to determine the short-term effectiveness of vision therapy on distance intermittent exotropia control. The results will help determine whether to proceed to a full-scale, long-term randomized trial.
Detailed description
Vision therapy (VT) is a commonly prescribed treatment for children with intermittent exotropia (IXT). The effectiveness of VT as a treatment modality for children with IXT is unknown because previous studies have largely limited observational or retrospective case series without comparison groups. The objective of this multi-centered pilot randomized trial of VT for IXT compared to observation is to 1) determine the short-term effectiveness of VT on distance intermittent exotropia and 2) determine the feasibility of recruitment and retention of children aged 8 to 16 years old with IXT to participate in a randomized trial of 20 weeks of in-office VT. The results of this trial will provide the needed information to plan and conduct a large-scale randomized trial to determine short-term and long-term effectiveness of VT for IXT in children, with the full-scale randomized trial helping to fill in the gaps in scientific knowledge concerning VT as a treatment for IXT.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Vision Therapy | Experimental | Other: Vision TherapyParticipants will receive 20 consecutive weeks of office-based vision therapy with home therapy. |
| Observation | No intervention | –Participants will receive no treatment for IXT is received during the study unless one of the deterioration criteria is met. |
Who may qualify
- Ages
- 8 to 16 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Vision TherapyAlso: Orthoptics20 consecutive weeks of office-based vision therapy with home therapy that aim to improve the participant's vergence skills, accommodative skills, and sensory fusion. | Other | Vision Therapy |
Primary outcome
Mean Distance Control Score
Time frame: 21 weeks
The primary analysis will be an intent-to-treat comparison of mean distance control score, determine by the intermittent exotropia office control scale, at outcome using an analysis of covariance model, which will adjust for baseline distance control. The intermittent exotropia office control scale grades the control on a scale of 0 (best control; phoria) to 5 (worst control; constant exotropia).
2 secondary outcomes
No Spontaneous Tropia
Time frame: 21 weeks
Change in Distance Control
Time frame: 21 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Sep 2026.
- Individual participant dataSharing planned: No
Related trials for Intermittent Exotropia
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Near Vergence Training for Distance Control in Intermittent Exotropia
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Improving Control of Alignment in Intermittent Exotropia
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A Comparative Study of the Efficacy of Myopia Control Lenses With Different Mechanisms on Controlling Myopia Progression in Patients With Intermittent Exotropia
Intermittent Exotropia, Myopia
Not yet recruiting
Visual Therapy for Intermittent Strabismus
Intermittent Strabismus, Exotropia Intermittent
Recruiting
Improving Control of Intermittent Exotropia
Intermittent Exotropia
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Angela Chen, OD, MS study chair
Southern California College of Optometry at Marshall B. Ketchum University
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Vision Therapy in people with Intermittent Exotropia, run by Southern California College of Optometry at Marshall B. Ketchum University at 6 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 3 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean Distance Control Score (time frame: 21 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Sep 2026.