Correlation between Interpupillary and Inner-Outer Intercanthal Distances in Individuals Younger than 20

Area of Science:

• Ophthalmology
• Pediatric Medicine
• Biometry

Background:

• Accurate interpupillary distance (IPD) measurement is crucial in pediatric ophthalmology.
• Traditional IPD measurement methods can be challenging in young children.
• Innerouter intercanthal distance (IOICD) offers a potential alternative measurement.

Purpose of the Study:

• To establish the correlation between interpupillary distance (IPD) and innerouter intercanthal distance (IOICD).
• To develop a regression equation for estimating IPD using IOICD measurements in pediatric populations.
• To assess the feasibility of using IOICD as a simpler proxy for IPD measurement.

Main Methods:

• Cross-sectional study involving 419 children aged 3 months to 20 years.
• Participants categorized into four age groups for analysis.
• Interpupillary distance (IPD) measured using a PD meter; innerouter intercanthal distance (IOICD) and other facial parameters measured with a ruler.

Main Results:

• A significant positive correlation was found between IOICD and IPD in the 3-5 and 12.5-20 year age groups.
• Nasal limbus to temporal limbus (NLTL) showed the best correlation with IPD in the ≤3 and 5-12.5 year groups.
• Regression equations demonstrated high accuracy for calculating IPD from IOICD in both male (r²=0.98) and female (r²=0.98) subjects.

Conclusions:

• Interpupillary distance (IPD) and innerouter intercanthal distance (IOICD) are strongly correlated in children.
• IOICD measurements are simpler and may serve as a reliable method for calculating IPD, especially in pediatric cases.
• This finding can simplify clinical assessments and improve the accuracy of IPD-related measurements in children.