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Congenitally Impaired Disparity Vergence in Children With Infantile Esotropia
Krista R Kelly1, Joost Felius2, Santoshi Ramachandran1
1Retina Foundation of the Southwest, Dallas, Texas, United States.
Insights
Infantile esotropia (ET) in children, regardless of duration, shows impaired disparity vergence. This suggests a congenital issue, meaning early correction may not fully restore normal binocular vision.
Area of Science:
- Ophthalmology
- Neuroscience
- Developmental Biology
Background:
- Infantile esotropia (ET) is a common childhood eye misalignment.
- The critical period for binocular vision development is crucial for establishing normal visual function.
- Understanding the timing of visual input is key to understanding ET's impact.
Purpose of the Study:
- To investigate congenital impairment of disparity vergence in infantile esotropia (ET).
- To compare disparity vergence in children with short-duration ET versus long-duration ET and healthy controls.
- To determine if short-duration ET preserves binocular input during critical developmental periods.
Main Methods:
- Enrolled 19 children (5-12 years) with infantile ET (short/long duration) and 22 healthy controls.
- Recorded eye movements during disparity and accommodative vergence using an EyeLink 1000 tracker.
- Compared mean response gains between groups and conditions.
Main Results:
- Children with both short and long-duration infantile ET exhibited reduced disparity vergence response gains compared to controls.
- No significant difference in accommodative vergence response gains was found between groups.
- P-values: short ET (P = 0.002), long ET (P < 0.001) for disparity vergence; P = 0.19 for accommodative vergence.
Conclusions:
- Infantile ET is associated with a congenital impairment of disparity vergence, irrespective of misalignment duration.
- Early correction of ET may allow some binocular disparity sensitivity but may not achieve normal levels.
- This suggests a fundamental deficit in the vergence system present from early development.
Purpose:
We examined whether congenital impairment of disparity vergence in infantile esotropia (ET) exists in children with short duration ET (≤3 months) compared with long-duration ET and healthy controls. A short duration of misalignment would allow for a substantial amount of balanced binocular input during the critical period of binocular disparity development.
Methods:
A total of 19 children aged 5 to 12 years and treated for infantile ET with a short (≤3 months; n = 10) or long (≥5 months; n = 9) duration of constant misalignment before alignment were enrolled. A total of 22 healthy control children were enrolled as a comparison group. Eye movements during disparity vergence and accommodative vergence were recorded using an EyeLink 1000 binocular eye tracker. Mean response gain was compared between and within groups to determine the effect of duration of misalignment and viewing condition.
Results:
Compared with controls, children with short (P = 0.002) and long (P < 0.001) duration infantile ET had reduced response gains for disparity vergence, but not for accommodative vergence (P = 0.19).
Conclusions:
Regardless of duration of misalignment, children with infantile ET had reduced disparity vergence, consistent with a congenital impairment of disparity vergence in infantile ET. Although early correction of misalignment increases the likelihood that some level of binocular disparity sensitivity will be present, normal levels may never be achieved.
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