Visual Therapy for Intermittent Strabismus

NCT07563959 | Not Yet Recruiting

• 1 other identifier: ViT(I)S
• Study Type: interventional
• Target: 30
• Locations: 0 countries
• Sites: N/A

Brief Summary

Intermittent strabismus is a condition in which the eyes occasionally become misaligned, affecting binocular vision, depth perception, and quality of life. Standard treatment often involves surgery of the eye muscles, although its effectiveness and timing remain debated. Visual therapy is a non-invasive alternative that uses structured exercises to improve eye coordination and binocular vision. However, there is limited high-quality evidence supporting its effectiveness in intermittent strabismus. This randomized controlled trial aims to evaluate whether a 12-session visual therapy program improves eye alignment, binocular vision, control of strabismus, and quality of life in individuals aged 8 to 50 years with intermittent horizontal strabismus. Participants will be assigned to either a visual therapy group or a control group without treatment. Visual therapy will include weekly in-office sessions combined with short daily home exercises. The study will assess changes before and after the intervention to determine whether visual therapy is an effective, non-invasive treatment option that could reduce the need for surgery.

Conditions

Intermittent Strabismus; Exotropia Intermittent; Esotropia Intermittent

Keywords

Intermittent Strabismus; Visual Therapy; Binocular Vision; Exotropia; Esotropia; Pediatric and Adult Strabismus; Quality of Life

Outcome Measures

Primary Outcomes (4)

• Change in Ocular Deviation

  Ocular deviation will be assessed using the alternate cover test with prism bars in primary gaze and Hirschberg test with image capture. The magnitude of deviation will be expressed in prism diopters (PD).

  Baseline (T0) to 12 weeks (T1)

• Change in Binocular Function (Fusion and Stereopsis)

  Binocular function will be assessed using the Worth 4 Dot test (fusion) and stereopsis tests at near distance.

  Baseline (T0) to 12 weeks (T1)

• Change in Strabismus Control

  Control of strabismus will be assessed using the Mohney and Holmes Office Control Score, a 5-point ordinal scale evaluating the frequency and control of ocular deviation.

  Baseline (T0) to 12 weeks (T1)

• Change in Vision-Related Quality of Life

  Quality of life will be assessed using validated questionnaires: AS-20 for adults and Intermittent Exotropia Questionnaire (IXTQ) for pediatric participants.

  Baseline (T0) to 12 weeks (T1)

Study Arms (2)

Visual Therapy

EXPERIMENTAL

Participants will receive a structured visual therapy program consisting of 12 weekly in-office sessions (1 hour each) combined with daily home-based exercises (\~10 minutes), with adherence monitoring.

Behavioral: Visual Therapy

Control

NO INTERVENTION

Participants will not receive any intervention during the study period. They will undergo the same baseline and post-study assessments as the experimental group.

Interventions

Visual Therapy BEHAVIORAL

A structured program of visual exercises designed to improve oculomotor control and binocular vision. The intervention includes 12 weekly in-office sessions (1 hour each) conducted at a specialized center, combined with daily home-based exercises (\~10 minutes), with adherence monitoring.

Visual Therapy

Eligibility Criteria

• Age: 8 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Individuals aged 8 to 50 years Diagnosis of intermittent horizontal strabismus (exotropia or esotropia) Absence of associated ocular, systemic, or neurological pathology Ability to understand and follow study instructions Willingness and motivation to complete 12 sessions of visual therapy (for the experimental group) Written informed consent (and assent for minors when applicable)

You may not qualify if:

• Previous visual therapy treatment Inability to attend in-office visual therapy sessions Presence of ocular, systemic, or neurological disease affecting vision Constant strabismus Cognitive or intellectual impairment limiting the ability to perform the exercises

Sponsors & Collaborators

• Universitat Politècnica de Catalunya: lead
• Hospital Universitari Mútua de Terrassa: collaborator

Related Publications (6)

• Sunyer-Grau, B., Quevedo, L., Rodríguez-Vallejo, M., & Argilés, M. (2023). Comitant strabismus etiology: extraocular muscle integrity and central nervous system involvement-a narrative review. Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie, 261(7), 1781-1792. https://doi.org/10.1007/s00417-022-05935-9

  RESULT

• Sunyer-Grau, B., Quevedo, L., Rodríguez-Vallejo, M., & Argilés, M. (2025). Surgical outcomes and etiological considerations in intermittent exotropia: a systematic narrative review. Strabismus, 33(3), 188-198. https://doi.org/10.1080/09273972.2024.2449563

  RESULT

• Ma MM, Kang Y, Chen C, Su C, Tian Z, Le M. Vision therapy for intermittent exotropia: A case series. J Optom. 2021;14(3):247-253. doi:10.1016/j.optom.2020.05.006

  RESULT

• Pang, Y., Gnanaraj, L., Gayleard, J., Han, G., & Hatt, S. R. (2021). Interventions for intermittent exotropia. The Cochrane database of systematic reviews, 9(9), CD003737. https://doi.org/10.1002/14651858.CD003737.pub4

  RESULT

• Alvarez TL, Vicci VR, Alkan Y, et al. Vision therapy in adults with convergence insufficiency: clinical and functional magnetic resonance imaging measures. Optom Vis Sci. 2010;87(12):E985-E1002. doi:10.1097/OPX.0b013e3181fef1aa

  RESULT

• Bui Quoc E, Milleret C. Origins of strabismus and loss of binocular vision. Front Integr Neurosci. 2014;8:71. Published 2014 Sep 25. doi:10.3389/fnint.2014.00071

  RESULT

MeSH Terms

Conditions

Esotropia; Exotropia; Strabismus

Condition Hierarchy (Ancestors)

Ocular Motility Disorders; Cranial Nerve Diseases; Nervous System Diseases; Eye Diseases

Central Study Contacts

Laura Asensio Jurado, PhD

CONTACT

0034636760450; asensiojlaura@upc.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Outcome assessors (optometrists) will be masked to group allocation. Participants and care providers cannot be masked due to the nature of the intervention.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD

Model Details: Participants will be randomized into two parallel groups. The experimental group will receive a structured visual therapy program consisting of 12 weekly in-office sessions combined with daily home-based exercises. The control group will not receive any intervention during the study period. Outcomes will be assessed at baseline and after completion of the intervention to compare changes between groups.

Study Record Dates

• First Submitted: April 26, 2026
• First Posted: May 4, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): July 1, 2028
• Last Updated: May 4, 2026

Record last verified: 2026-04