NCT04487249 · Southern California College of Optometry at Marshall B. Ketchum University
Trial of Vision Therapy for Intermittent Exotropia
(VT-IXT)
What this study is about
The main objective of this randomly assigned 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 randomly assigned trial.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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)
Where
- Birmingham, Alabama
- Fullerton, California
- Stanford, California
- Columbus, Ohio
- Philadelphia, Pennsylvania
- Memphis, Tennessee
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 5, 2025 · Source of record for eligibility and locations