The Association of Axial Length with Age and Gender in Preschool Children

Abstract

 

Purpose:

 

To explore the association of axial length (AL) with age and gender in a population-based sample of preschool children.

 

Methods:

 

AL was measured using the IOL Master in a population-based sample of children aged 24 to 72 months in the Multi-ethnic Pediatric Eye Disease Study. In this report, locally weighted scatterplot smoothing was utilized to describe the general pattern of AL as a function of age. General linear models were used to quantitatively evaluate the associations of AL with age and gender, adjusted for race/ethnicity.

 

Results:

 

AL measurements were successfully obtained in 5161 (82.6%) of the 6245 eligible children. Of the 5161 children with complete data, 2599 (50.4%) were girls and 2562 (49.6%) were boys; 1825 (35.4%) were African-American, 1871 (36.3%) were Hispanic, 935 (18.1%) were Non-Hispanic White, and 530 (10.3%) were Asian. On average, AL was longer by 0.022mm for each month of older age. This linear relationship was statistically significant after adjusting for gender and ethnicity (p<0.0001). On average, AL was 0.48mm longer in boys compared to girls (p<0.0001). Furthermore, on subgroup analyses of children aged 48-72 months, there was a suggestion that the rate of growth in males was approximately 50% greater (0.023mm/month) than that in females (0.015mm/month)(p=0.04).

 

Conclusions:

 

These data provide the first population-based assessment of the relationship between ocular axial elongation, age and gender in children aged 2-6 years. These age and gender related differences provide insight into the role that axial elongation plays in refractive development in preschool children. However, these data need to be confirmed in prospective longitudinal studies.  

 

Keywords: visual development: infancy and childhood