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Changes in the interpupillary distance with age and its effect on the near fusion free position
1School of Optometry, University of New South Wales, Sydney, Australia.
Insights
The convergence system in children can adapt to changes in interpupillary distance (IPD) with age. This study found differences in IPD growth rates between sexes and age groups, impacting near fusion free position.
Area of Science:
- Ophthalmology
- Pediatric Optometry
- Binocular Vision
Background:
- Interpupillary distance (IPD) changes throughout childhood.
- Understanding these changes is crucial for assessing binocular vision function.
- The near fusion free position is a key indicator of vergence system status.
Purpose of the Study:
- To investigate how the rate of age-related interpupillary distance (IPD) change affects the near fusion free position in children.
- To identify potential differences in IPD growth and its impact on binocular vision between genders and age groups.
Main Methods:
- Tested 352 children aged 2-16 years.
- Measured interpupillary distance using a modified Viktorin's method.
- Assessed near fusion free position with a modified Maddox Wing.
Main Results:
- Significant differences in IPD growth rates were observed between males and females.
- Children under 5 years showed different IPD growth rates compared to older children.
- Orthophoria was common in younger children, while heterophoria increased with age.
Conclusions:
- The oculomotor control system demonstrates the capacity to compensate for age-related alterations in interpupillary distance.
- Age and sex are significant factors influencing IPD growth rates and near phoria in children.
Purpose:
The effect of the rate of the interpupillary distance (IPD) change with age on the near fusion free position was investigated in the present study.
Methods:
Three hundred and fifty-two children aged from 2 to 16 years of age were tested. Interpupillary distance was estimated with a modified Viktorin's method and the near fusion free position was measured with a modified Maddox Wing.
Results:
The results reveal a significant difference in IPD growth rate between females and males and between children aged below and above 5 years. Most children below 5 years of age were orthophoric, but heterophoria became more common above 5 years of age.
Conclusion:
The present study suggests that the oculomotor control system for convergence can compensate for age changes in IPD.