Vision Therapy for Intermittent Exotropia

(VT-IXT Trial)

Recruiting at 5 trial locations

Overseen By Angela Chen, OD, MS

Age: < 18

Sex: Any

Trial Phase: Academic

Sponsor: Southern California College of Optometry at Marshall B. Ketchum University

Disqualifiers: Recent IXT treatment, Vision therapy, Surgery, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 4 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 20 weeks

58 Participants Needed

Trial Summary

What is the purpose of this trial?

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.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

Is vision therapy safe for humans?

Research on vision therapy, including studies on active vision therapy and overminus lens therapy, suggests it is generally safe for humans, with no significant safety concerns reported in the studies. ^{1 2 3 4 5}

How is vision therapy different from other treatments for intermittent exotropia?

Vision therapy for intermittent exotropia is unique because it focuses on exercises to improve eye coordination and control, potentially offering higher success rates than surgery alone. It involves office-based vergence/accommodative therapy with home exercises, making it a non-invasive option compared to surgical interventions. ^{6 7 8 9 10}

Research Team

Angela Chen, OD, MS

Principal Investigator

Southern California College of Optometry at Marshall B. Ketchum University

Eligibility Criteria

This trial is for kids aged 8-16 with a specific eye alignment issue called intermittent exotropia, where one eye occasionally drifts outward. They should have certain levels of control over their eye movement and good depth perception. Kids who plan to move soon or can't commit to the study's process are not eligible.

Inclusion Criteria

You have a mean distance control score of 2 points or more, with at least one measure being 3 points or higher.

Your average near control score is less than 5 points.

I am between 8 and 16 years old.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive 20 consecutive weeks of office-based vision therapy with home therapy

20 weeks

Observation

Participants in the observation group receive no treatment unless deterioration criteria are met

20 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

1 week

Treatment Details

Interventions

• Vision Therapy

Trial Overview The study tests if vision therapy can help manage intermittent exotropia better than just watching the condition without treatment. Participants will be randomly assigned to either receive vision therapy or be observed, helping decide if more extensive research is needed.

Participant Groups

Group I: Vision Therapy Experimental Treatment 1 Intervention

Participants will receive 20 consecutive weeks of office-based vision therapy with home therapy.

Group II: Observation Active Control 1 Intervention

Participants will receive no treatment for IXT is received during the study unless one of the deterioration criteria is met.

Vision Therapy is already approved in United States, Canada, European Union for the following indications:

Approved in United States as Vision Therapy for:

• Intermittent Exotropia
• Strabismus
• Convergence Insufficiency

Approved in Canada as Vision Therapy for:

• Intermittent Exotropia
• Strabismus
• Convergence Insufficiency

Approved in European Union as Vision Therapy for:

• Intermittent Exotropia
• Strabismus
• Convergence Insufficiency

Who Is Running the Clinical Trial?

Southern California College of Optometry at Marshall B. Ketchum University

Lead Sponsor

Trials

24

Recruited

1,400+

Southern College of Optometry

Collaborator

Trials

8

Recruited

390+

Case Western Reserve University

Collaborator

Trials

314

Recruited

236,000+

Salus University

Collaborator

Trials

16

Recruited

1,100+

American Academy of Optometry

Collaborator

Trials

6

Recruited

290+

University of Alabama at Birmingham

Collaborator

Trials

1,677

Recruited

2,458,000+

Stanford University

Collaborator

Trials

2,527

Recruited

17,430,000+

Ohio State University

Collaborator

Trials

891

Recruited

2,659,000+

Findings from Research

In a study of 186 children with intermittent exotropia (IXT), 31.6% showed improvement in their eye alignment and stereoacuity after 1 year of low-dose part-time patching for 2 hours daily.

Factors such as convergence insufficiency, poor distance stereopsis, and larger exotropic deviation at distance were associated with a better response to part-time patching, suggesting it may be an effective non-surgical treatment option for certain patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Factors associated with the effectiveness of part-time patching for intermittent exotropia in children. Choi, H., Kim, SJ., Jung, J., et al.[2022]

In a study involving 20 adults with anisometropic amblyopia, active vision therapy over five sessions led to a significant improvement in best corrected visual acuity (BCVA), with scores improving from 0.37 to 0.14 Log MAR.

The results suggest that even adults can experience plasticity in their visual system, indicating that vision therapy can be beneficial for improving visual acuity in older patients with amblyopia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Visual Acuity Improvement in Adult Anisometropic Amblyopes After Active Vision Therapy. Sharbatoghli, L., Hashemi, H., Mohamadi, A., et al.[2022]

In a study of 76 children aged 3-8 with intermittent exotropia, alternate part-time patching significantly improved deviation control compared to observation, particularly noted at both near and far distances after 3 and 6 months.

While stereoacuity (the ability to perceive depth) did not show significant differences between the patching and observation groups, the patching group exhibited greater improvements in stereoacuity from baseline, indicating potential benefits beyond just deviation control.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The influence of alternate part-time patching on control of intermittent exotropia: a randomized clinical trial. Akbari, MR., Mehrpour, M., Mirmohammadsadeghi, A.[2021]

In a study of 65 children aged 5 to 16 with amblyopia, both active vision therapy (AVT) and conventional patching therapy significantly improved visual acuity in the amblyopic eye, but there was no significant difference in the level of improvement between the two methods.

Active vision therapy was found to be more effective than patching therapy in enhancing stereoacuity, with a significant gain in stereoacuity for the AVT group compared to the patching group, indicating that AVT may offer additional benefits in depth perception.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of active vision therapy compared to conventional patching therapy on visual acuity and stereoacuity in children with amblyopia. Suwal, R., Dev, MK., Khatri, B., et al.[2023]

Overminus spectacle therapy significantly improved distance control of intermittent exotropia (IXT) in children after 12 months of treatment, with a mean control score of 1.8 compared to 2.8 in the nonoverminus group (P < 0.001).

However, the improvement in exotropia control was not sustained after the treatment was tapered off, as scores were similar between groups at 18 months, and the overminus group experienced a greater myopic shift, with 17% of children showing a shift greater than 1.00 D.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Overminus Lens Therapy for Children 3 to 10 Years of Age With Intermittent Exotropia: A Randomized Clinical Trial. Chen, AM., Erzurum, SA., Chandler, DL., et al.[2022]

Vision therapy can be more effective than surgery for treating intermittent exotropia, but it may not work for every patient, highlighting the need for personalized treatment plans.

The case presented demonstrates that combining vision therapy with surgery can be a viable option for patients who do not respond adequately to vision therapy alone.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Management of intermittent exotropia using a combination of vision therapy and surgery. Gallaway, M., Vaxmonsky, T., Scheiman, M.[2004]

In a study of 150 patients with intermittent exotropia, combining surgery with orthoptic/occlusion therapy showed the highest success rates in treatment, significantly outperforming other methods.

The combination treatment not only led to greater reductions in exodeviation at all follow-up points but also proved more effective in terms of the amount of correction achieved per millimetre of surgery performed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intermittent exotropia: comparison of treatments. Figueira, EC., Hing, S.[2016]

Vision therapy effectively improved binocular alignment in two cases of intermittent exotropia, with significant stability observed in ocular deviation after treatment, as confirmed by 3D videooculography (VOG).

The use of 3D VOG provided objective measurements of the patients' eye alignment and revealed improvements in both vertical and torsional components of eye movement, highlighting its potential as a valuable tool in assessing treatment outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluation of Binocular Vision Therapy Efficacy by 3D Video-Oculography Measurement of Binocular Alignment and Motility. Laria, C., Pinero, DP.[2018]

In a study of 136 children aged 7 to 17 with intermittent exotropia, early postoperative orthoptic therapy significantly reduced the likelihood of suboptimal surgical outcomes, with only 20.5% of patients in the therapy group experiencing issues compared to 42.6% in the control group.

The therapy also led to improvements in stereopsis, fusional exotropia control, and convergence amplitude, indicating that orthoptic therapy enhances both surgical success and binocular function after surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effects of Orthoptic Therapy on the Surgical Outcome in Children with Intermittent Exotropia: Randomised Controlled Clinical Trial. Xu, M., Peng, Y., Zheng, F., et al.[2023]

Office-based vergence/accommodative therapy combined with home reinforcement significantly improved control of intermittent exotropia in patients aged 5 to 22, with a notable change in Office Control Scores after treatment (p < 0.001).

The therapy was effective for both patients who had undergone strabismus surgery and those who had not, indicating its broad applicability in managing intermittent exotropia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Vision therapy for intermittent exotropia: A case series. Ma, MM., Kang, Y., Chen, C., et al.[2021]

References

1. United States pubmed.ncbi.nlm.nih.gov

Factors associated with the effectiveness of part-time patching for intermittent exotropia in children. [2022]

2. New Zealand pubmed.ncbi.nlm.nih.gov

Visual Acuity Improvement in Adult Anisometropic Amblyopes After Active Vision Therapy. [2022]

3. Germany pubmed.ncbi.nlm.nih.gov

The influence of alternate part-time patching on control of intermittent exotropia: a randomized clinical trial. [2021]

4. Spain pubmed.ncbi.nlm.nih.gov

Impact of active vision therapy compared to conventional patching therapy on visual acuity and stereoacuity in children with amblyopia. [2023]

5. United States pubmed.ncbi.nlm.nih.gov

Overminus Lens Therapy for Children 3 to 10 Years of Age With Intermittent Exotropia: A Randomized Clinical Trial. [2022]

6. United States pubmed.ncbi.nlm.nih.gov

Management of intermittent exotropia using a combination of vision therapy and surgery. [2004]

7. Australia pubmed.ncbi.nlm.nih.gov

Intermittent exotropia: comparison of treatments. [2016]

8. United States pubmed.ncbi.nlm.nih.gov

Evaluation of Binocular Vision Therapy Efficacy by 3D Video-Oculography Measurement of Binocular Alignment and Motility. [2018]

9. Switzerland pubmed.ncbi.nlm.nih.gov

The Effects of Orthoptic Therapy on the Surgical Outcome in Children with Intermittent Exotropia: Randomised Controlled Clinical Trial. [2023]

10. Spain pubmed.ncbi.nlm.nih.gov

Vision therapy for intermittent exotropia: A case series. [2021]