Trial of Vision Therapy for Intermittent Exotropia

Intermittent Exotropia Clinical Trial

— VT-IXT  

Official title:

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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04487249
• Other study ID #: 20-08
• Status: Recruiting
• Phase: N/A
• Start date: October 1, 2021
• Est. completion date: December 2025

Study information

• Verified date: November 2023
• Source: Southern California College of Optometry at Marshall B. Ketchum University
• Contact: Angela Chen, OD, MS
• Phone: 714-463-7569
• Email: angelachen[@]ketchum.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical 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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 58
• Est. completion date: December 2025
• Est. primary completion date: December 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 8 Years to 16 Years

Eligibility

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)

Related Conditions & MeSH terms

• Exotropia
• Intermittent Exotropia

Intervention

Other:
• Vision Therapy
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.

Locations

Country	Name	City	State
United States	University of Alabama in Birmingham	Birmingham	Alabama
United States	Ohio State University	Columbus	Ohio
United States	Southern California College of Optometry at Marshall B. Ketchum University	Fullerton	California
United States	Southern College of Optometry	Memphis	Tennessee
United States	Salus University	Philadelphia	Pennsylvania
United States	Stanford University	Stanford	California

Sponsors (8)

Lead Sponsor	Collaborator
Southern California College of Optometry at Marshall B. Ketchum University	American Academy of Optometry, Case Western Reserve University, Ohio State University, Salus University, Southern College of Optometry, Stanford University, University of Alabama at Birmingham

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Change in Vergence and Accommodative Measures	The near point of convergence, positive and negative fusional vergence ranges at distance and near, vergence facility, accommodative amplitude, and accommodative facility at outcome will be compared between treatment groups adjusting for the corresponding baseline value. The analysis will be completed separately for each vergence and accommodative measures.	21 weeks
Other	Suppression Status	Suppression status will be compared at outcome between treatment groups, adjusting for baseline suppression status. Suppression status when the participant's eyes are in tropic position will be assessed using the suppression scale ranging from 0 (negligible suppression) to 4 (dense suppression).	21 weeks
Other	Objective Eye Movement Recordings	Frequency of intermittent exotropia by objective eye movement recordings will be compared between treatment groups.	21 weeks
Primary	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).	21 weeks
Secondary	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.	21 weeks
Secondary	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.	21 weeks