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Development of phoria in children
J J Walline1, D O Mutti, K Zadnik
1The Ohio State University College of Optometry, Columbus 43210-1240, USA.
Insights
Phoria prevalence in children is typically orthophoric at distance. Near phoria shows a shift towards esophoria with age, with exophoria decreasing and esophoria increasing from kindergarten to fifth grade.
Area of Science:
- Ophthalmology
- Pediatric Optometry
- Vision Science
Background:
- Phoria prevalence data in children is limited compared to adults.
- This study addresses the scarcity of information on childhood phoria.
- Utilizes data from the Orinda Longitudinal Study of Myopia.
Purpose of the Study:
- To document the prevalence of phoria in a large, population-based sample of nonstrabismic children.
- To investigate the changes in phoria with age in childhood.
- To provide normative data for childhood phoria.
Main Methods:
- Employs modified clinical technique vision screening.
- Collects both cross-sectional (N=1495) and longitudinal (N=469) data.
- Uses cover tests to classify phoria (orthophoria, esophoria, exophoria) in 2-delta steps.
Main Results:
- 97% of children are orthophoric at distance, with no significant age-related changes.
- Near phoria exhibits a more normal distribution.
- Between kindergarten and fifth grade, exophoria decreased by 10.8% and esophoria increased by 5.5%.
Conclusions:
- Children are generally orthophoric or exophoric at near distances.
- A convergent shift in near phoria occurs as children age.
- Findings highlight age-related changes in binocular vision in children.
Background:
Although the prevalence of phoria in adults is well documented, data are scarce on phoria in children. We present results using modified clinical technique vision screening and data from the Orinda Longitudinal Study of Myopia on a large, population-based sample of nonstrabismic children to document the prevalence of phoria with age.
Methods:
We collected cross-sectional (N = 1495) and longitudinal (N = 469) data. Phoria data were collected by cover tests administered by one observer who subjectively classified phoria as orthophoria, esophoria, or exophoria in 2 delta steps.
Results:
Ninety-seven percent of the children were orthophoric at distance, and there were no significant changes with age. Near phoria showed a more normal distribution, with a 10.8% decrease in the prevalence of exophoria (from 31.8 to 21.0%) and a 5.5% increase in the prevalence of esophoria (from 6.7 to 12.2%) between kindergarten and fifth grade.
Conclusions:
Children are typically orthophoric or exophoric at near, but convergent shifts occur with age.