Distribution of Eccentricity in Children Aged 6-12 Years

To determine the distribution of eccentricity and its association with some biometric and demographic parameters.

In this cross-sectional study, the target population was primary school children aged 6 to 12 years from Shahroud, northeast Iran. Scheimpflug imaging was done using the Pentacam. Multiple linear regression analysis was applied to study the association between Eccentricity (ECC) and independent variables like age, sex, living place as well as biometric parameters.

Of the 6624 selected students, 5620 participated in the study of whom 4968 were eligible for analysis in this study. About half (52.4%) of the students were boys. The mean ECC was 0.600 (95% CI: 0.597-0.602) in total, 0.597 (95% CI: 0.594-0.600) in boys and 0.603 (95% CI: 0.599-0.607) in girls. The mean ECC was 0.611 in 6-year-old and 0.588 in 12-year-old children. The mean ECC was 0.590 in rural and 0.601 in urban children. The mean ECC was 0.600, 0.604, and 0.604 in emmetropic, myopic, and hyperopic children, respectively. Multiple linear regression analysis showed that ECC decreased with age (Coefficient: -0.004; 95%CI: -0.006 to -0.003), was higher in urban areas (Coefficient: 0.008; 95%CI: 0.002 to 0.014), had a direct association with axial length, and had an indirect association with lens thickness, central corneal thickness, and anterior chamber depth.

The cornea had a prolate shape in children and eccentricity value decreased with age. The results of this study add to the existing knowledge and can be used in differentiating normal from abnormal corneal shapes in children.