Early Versus Delayed Surgery for Infantile Esotropia

The Hospital for Sick Children71 enrolled

Overview

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).

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.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Esotropia

Interventions

mVEP TestingPROCEDURE

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.

Stereoacuity TestingPROCEDURE

Subjects will have their 3D perception measured using standard clinical stereo tests (Randot, Lang, Titmus).

Optokinetic nystagmus testingPROCEDURE

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.

Eligibility

Sex: ALLMin age: 3 MonthsMax age: 23 Months

Medical Language ↔ Plain English

Inclusion Criteria: 1. onset of esotropia after 10 weeks of age; 2. constant esotropia ≥ 20° (40 prism diopter or PD) at near (1/3 m) on two examinations, separated by 2-4 weeks; and 3. refractive error ≤ +3.00 diopters (far-sightedness). Exclusion Criteria: 1. gestational age \< 34 weeks; 2. birth weight ≤ 1500 g; 3. ventilator treatment in the newborn period; 4. history of meningitis or other major medical event; 5. developmental delay; 6. incomitant or paralytic strabismus; 7. manifest nystagmus or head bobbing; 8. prior eye muscle surgery; 9. prior treatment of amblyopia or spectacle correction for refractive errors; 10. presence of structural ocular anomalies.

Locations (1)

The Hospital for Sick Children

Toronto, Ontario, Canada

Outcomes

Primary Outcomes

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.

Time frame: at age 2 years

Stereopsis

This measures the level of 3D depth perception.

Time frame: 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.

Time frame: 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).

Time frame: at 2 and 5 years of age

Data from ClinicalTrials.gov

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