Improving Control of Intermittent Exotropia

To determine whether use of dichoptic movies for 8 weeks may be helpful in improving control alignment in children with intermittent exotropia (IXT), thus allowing IXT to be managed non-surgically

Study Overview

• Status: Recruiting
• Conditions: Intermittent Exotropia
• Intervention / Treatment: Other: dichoptic videos; Other: standard videos

Detailed Description

Intermittent exotropia (IXT) is the most common form of strabismus, characterized by an outward deviation of the eyes that is primarily manifest during distance fixation and can intermittently be controlled by fusional mechanisms. Less than 30% of children have good long-term outcomes following treatment for spontaneously manifest IXT with current non-surgical treatments (prism therapy, over-minus lenses, or vision therapy). The limited efficacy of current non-surgical treatments for IXT is thought to arise from underlying sensory deficits, particularly interocular suppression, which compromises binocular function. This underscores the need for sensory-directed interventions aimed at reducing suppression and thereby enhancing the potential for stable binocular outcomes.

In this study, children will be randomized to watch engaging videos streamed at home that are either dichoptic or standard (control) format. The aim is to determine whether the dichoptic format will decrease suppression and improve control of eye alignment . In previous research, use of dichoptic games and movies by children with amblyopia has shown to reduce suppression.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Eileen Birch, PhD; Phone Number: 2143633911; Email: ebirch@retinafoundation.org
• Study Contact Backup: Name: Reed Jost, MS; Phone Number: 2143633911; Email: reedjost@retinafoundation.org

Study Locations

• United States
  • Texas
    • Dallas, Texas, United States, 75231
      • Recruiting
      • Retina Foundation of the Southwest
      • Principal Investigator: Eileen E Birch, PhD
      • Contact: Pediatric Laboratory; Phone Number: 113 2143633911

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of IXT or XT at Distance & IXT or XP at near (Basic or Pseudo Divergence Excess subtype of IXT)
• No surgery planned for 6 months

Exclusion Criteria:

• Prior eye muscle surgery
• Prior binocular treatment or vision therapy
• Amblyopia
• Neurological conditions, seizure disorders, vestibular abnormalities, or frequent headache
• Other eye conditions (refractive error OK)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group 1: Dichoptic Videos; dichoptic videos streamed at home 1 hour per day, 5 days per week	Other: dichoptic videos; custom designed dichoptic videos
Sham Comparator: Group 2: Standard Videos; standard videos streamed at home 1 hour per day, 5 days per week	Other: standard videos; standard videos

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Improvement in control of intermittent exotropia	change percent time alignment is present at 8 weeks vs at baseline	8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Improvement in control of intermittent exotropia	change percent time alignment is present at 4 weeks vs at baseline	4 weeks
Improvement in control of intermittent exotropia	change percent time alignment is present at 12 weeks off-treatment weeks vs at baseline	12 weeks off-treatment
Change in distance stereoacuity	change in Distance Randot test score at 4 weeks vs at baseline	4 weeks
Change in distance stereoacuity	change in Distance Randot test score at 8 weeks vs at baseline	8 weeks
Change in distance stereoacuity	change in Distance Randot test score at 12 weeks off-treatment vs at baseline	12 weeks off-treatment
Change in quality of life	Change in IXTQ questionnaire (Rasch-scored on a 0-100 scale) at 8 weeks vs at baseline	8 weeks
Change in quality of life	Change in IXTQ questionnaire (Rasch-scored on a 0-100 scale) ay 12 weeks off-treatment vs at baseline	12 weeks off-treatment

Collaborators and Investigators

• Sponsor: Retina Foundation of the Southwest
• Investigators: Principal Investigator: Eileen E Birch, Retina Foundation of the Southwest

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2026
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): August 1, 2028

Study Registration Dates

• First Submitted: November 19, 2025
• First Submitted That Met QC Criteria: November 26, 2025
• First Posted (Actual): December 9, 2025

Study Record Updates

• Last Update Posted (Actual): April 8, 2026
• Last Update Submitted That Met QC Criteria: April 2, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 03 IXT2 2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No