Early Versus Delayed Surgery for Infantile Esotropia

Study Overview
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Brief Summary
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The goal of this study is to determine whether corrective surgery done earlier than the current standard can better improve the visual and eye movement deficits in children with infantile esotropia (crossed eyes in infancy).

Detailed Description
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While there is a uniform agreement among pediatric ophthalmologists that most infantile esotropia requires surgical correction, the proper timing of surgery is controversial. In North America, the typical age at surgery ranges from 11-18 months. Unfortunately, despite successful surgical realignment of the eyes, the sensory and eye movement deficits often persist. Recently, some pediatric ophthalmologists have advocated earlier surgery. The rationale for early surgery stems from animal and human research showing that early realignment of the eyes within an early critical period allows normal development of the sensory and eye movement systems.

Official Title
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Early Versus Delayed Surgery for Infantile Esotropia: A Clinical Evaluation of Sensory and Motor Outcomes

Conditions
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Esotropia

Intervention / Treatment
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* Procedure: mVEP Testing
* Procedure: Stereoacuity Testing
* Procedure: Optokinetic nystagmus testing
* Procedure: Motion detection testing
* Procedure: Motion discrimination testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: onset of esotropia after 10 weeks of age; constant esotropia ≥ 20° (40 prism diopter or PD) at near (1/3 m) on two examinations, separated by 2-4 weeks; and refractive error ≤ +3.00 diopters (far-sightedness). Exclusion Criteria: gestational age < 34 weeks; birth weight ≤ 1500 g; ventilator treatment in the newborn period; history of meningitis or other major medical event; developmental delay; incomitant or paralytic strabismus; manifest nystagmus or head bobbing; prior eye muscle surgery; prior treatment of amblyopia or spectacle correction for refractive errors; presence of structural ocular anomalies.

Ages Eligible for Study
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Minimum Age: 3 Months
Maximum Age: 23 Months

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Early Surgery<br>This group will be made up of subjects whose parents choose to have them undergo corrective surgery at or before age 11 months. | Procedure: mVEP Testing<br>* Five small sensors are placed on the head which record the brain's response to moving stripes that are displayed on a computer screen. Each eye is tested while the other eye is patched. Each recording trial lasts about 10 seconds, and several trials are done for each eye.<br>Procedure: Stereoacuity Testing<br>* Subjects will have their 3D perception measured using standard clinical stereo tests (Randot, Lang, Titmus).<br>Procedure: Optokinetic nystagmus testing<br>* Subjects will be asked to view a screen with vertical stripes moving in both leftward and rightward directions while their eye movements are recorded using a remote video-based eye tracker.<br>Procedure: Motion detection testing<br>* Subjects will view a computer screen that has two panels of dots on them. The subject will be required to pick which panel has a section of dots that are moving in a specific direction (ie. nasalward/temporalward).<br>Procedure: Motion discrimination testing<br>* Subjects will view a computer screen that has two panels of randomly moving dots on them. The subject will be required to pick which panel has a section of dots that are moving in a specific direction (ie. nasalward/temporalward).<br>|
| Standard Surgery<br>This group will be made up of subjects who present after age 11 months or whose parents choose to have them undergo corrective surgery between 11-18 months. | Procedure: mVEP Testing<br>* Five small sensors are placed on the head which record the brain's response to moving stripes that are displayed on a computer screen. Each eye is tested while the other eye is patched. Each recording trial lasts about 10 seconds, and several trials are done for each eye.<br>Procedure: Stereoacuity Testing<br>* Subjects will have their 3D perception measured using standard clinical stereo tests (Randot, Lang, Titmus).<br>Procedure: Optokinetic nystagmus testing<br>* Subjects will be asked to view a screen with vertical stripes moving in both leftward and rightward directions while their eye movements are recorded using a remote video-based eye tracker.<br>Procedure: Motion detection testing<br>* Subjects will view a computer screen that has two panels of dots on them. The subject will be required to pick which panel has a section of dots that are moving in a specific direction (ie. nasalward/temporalward).<br>Procedure: Motion discrimination testing<br>* Subjects will view a computer screen that has two panels of randomly moving dots on them. The subject will be required to pick which panel has a section of dots that are moving in a specific direction (ie. nasalward/temporalward).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motion visual evoked potential (mVEPs) asymmetry | mVEP measures the perception of nasalward and temporalward motion for each eye at the cortical level. A nasal bias index (NBI) is calculated, which will show whether subjects perceive motion better for one direction over the other. | at age 2 years | 
| Stereopsis | This measures the level of 3D depth perception. | at 2 and 5 years of age | 
| Optokinetic nystagmus (OKN) asymmetry | OKN is measured in both the nasalward and temporalward directions for each eye. From this a nasal bias index (NBI) is calculated, which will show whether subjects perceive motion better in one direction or the other. | at age 5 years | 
| Global Motion Perception | Motion perception will be tested using two tasks: motion detection (at age 2 and 5 years) and motion discrimination (at age 5 years). | at 2 and 5 years of age | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pediatrics, Esotropia, Surgery