Controlled Intermittent Alternate Occlusion (CIAO) Therapy for Intermittent Exotropia

Study Overview
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Brief Summary
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To determine the effectiveness of alternate occlusion therapy for the treatment of IXT among patients aged 3 to < 11 years old.

Detailed Description
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Intermittent exotropia (IXT) is the most common form of childhood-onset exotropia with an incidence of 32.1 per 100,000 in children. Before surgery, many cases of IXT are treated using non-surgical interventions, such as part-time alternate occlusion. However, the alternating occlusion with traditional patches is usually out of control. The investigators are uncertain about the amount of alternating in patching treatment. Here, the investigators introduce controlled intermittent alternating occlusion (CIAO) therapy, which is provided by a new electronic device, -liquid crystal glasses. This study is to determine the effectiveness of alternate occlusion therapy for the treatment of IXT among patients aged 3 to < 11 years old. Children with IXT will be randomized into either an observation group or a CIAO therapy group.

Official Title
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A Clinical Trial of Observation Versus Controlled Intermittent Alternate Occlusion (CIAO) Therapy for Intermittent Exotropia

Conditions
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Intermittent Exotropia

Intervention / Treatment
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* Device: CIAO therapy Amblyz glasses


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Intermittent exotropia (manifest deviation) meeting all of the following criteria: Intermittent exotropia at distance OR constant exotropia at distance and either intermittent exotropia or exophoria at near Exodeviation at least 15PD at distance OR near measured by prism and alternate cover test (PACT) Exodeviation at least 10PD at distance measured by PACT No previous surgical or non-surgical treatment for IXT (other than refractive correction) Visual acuity in the worse eye 0.3 logMAR or better (20/40 on ATS HOTV or 70 letters on E-ETDRS) for children ≥ 3 years of age No interocular difference of visual acuity more than 0.2 logMAR (2 lines on ATS HOTV or 10 letters on E-ETDRS) for children ≥ 7 years of age Investigator not planning to initiate amblyopia treatment No hyperopia greater than +3.50 D spherical equivalent in either eye No myopia greater than -6.00 D spherical equivalent in either eye No prior strabismus, intraocular, or refractive surgery No abnormality of the cornea, lens, or central retina Investigator willing to observe the IXT untreated for 3 years unless specific criteria for deterioration are met. Exclusion Criteria: N/A

Ages Eligible for Study
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Minimum Age: 3 Years
Maximum Age: 11 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CIAO Therapy<br>Intervention with wearing 3-hour daily CIAO therapy glasses | Device: CIAO therapy Amblyz glasses<br>* 3-hour CIAO Therapy Amblyz glasses<br>|
| No Intervention: Observation<br>To observe as one kind of standard care for IXT. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Composite Measure of IXT Control Score | IXT control score: referring to the Pediatric eye disease investigator group (PEDIG). PEDIG scale of control for IXT 1-5 is defined as the following: 5 = Constant exotropia 4 = exotropia > 50% of the 30-sec period before dissociation 3 = exotropia < 50% of the 30-sec period before dissociation 2 = No exotropia unless dissociated, recovers in > 5 sec 1 = No exotropia unless dissociated, recovers in 1-5 sec 0 = No exotropia unless dissociated, recovers in < 1 sec (phoria) Not Applicable = No exotropia present | 12 weeks; 24 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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IXT