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Trial of Vision Therapy for Intermittent Exotropia

A Pilot Randomized Trial Evaluating Short-Term Effectiveness of Vision Therapy in Children With Intermittent Exotropia

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04487249
Acronym
VT-IXT
Enrollment
47
Registered
2020-07-27
Start date
2021-10-01
Completion date
2026-04-30
Last updated
2026-09-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Intermittent Exotropia

Keywords

Intermittent Exotropia, Vision Therapy

Brief 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.

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.

Interventions

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.

Sponsors

Southern California College of Optometry at Marshall B. Ketchum University
Lead SponsorOTHER
Stanford University
CollaboratorOTHER
Ohio State University
CollaboratorOTHER
Salus University
CollaboratorOTHER
University of Alabama at Birmingham
CollaboratorOTHER
Southern College of Optometry
CollaboratorOTHER
Case Western Reserve University
CollaboratorOTHER
American Academy of Optometry
CollaboratorOTHER
University of Houston
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
8 Years to 16 Years
Healthy volunteers
No

Inclusion criteria

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)

Design outcomes

Primary

MeasureTime frameDescription
Mean Distance Control Score21 weeksThe 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).

Secondary

MeasureTime frameDescription
No Spontaneous Tropia21 weeksThe 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.
Change in Distance Control21 weeksThe proportion of participants with \>= 1 point change in control and \>= 2 points change in control will be compared between treatment groups.

Countries

United States

Contacts

STUDY_CHAIRAngela Chen, OD, MS

Southern California College of Optometry at Marshall B. Ketchum University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 4, 2026