Trial of Vision Therapy for Intermittent Exotropia (VT-IXT)

Southern California College of Optometry at Marshall B. Ketchum University

Status: Enrolling

Conditions: Intermittent Exotropia

Treatments: Other: Vision Therapy

Study type: Interventional

Funder types: Other

Identifiers

NCT04487249

20-08

Details and patient eligibility

About

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.

Full 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.

Enrollment: 58 estimated patients

Sex: All

Ages: 8 to 16 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

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)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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58 participants in 2 patient groups

Vision Therapy

Experimental group

Description:

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

Treatment:

Other: Vision Therapy

Observation

No Intervention group

Description:

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