A Mathematical Model for Axial Length Estimation in a Myopic Pediatric Population Based on Easily Obtainable Variables

Abstract

Determining the axial length (AL) of the eye is of significant interest in the management of myopia. However, the devices that allow this value to be obtained are either expensive, for example, optical biometers, or inconvenient for use in pediatric population, such is the case with ultrasound biometers. Therefore, this study aimed to develop a mathematical model for estimating the AL value based on easily obtainable variables, with the novel addition of body height to the analysis. A total of 170 eyes of 85 myopic volunteers (mean age of 10.8 ± 1.45 years, ranging from 7 to 14 years) were included in the analysis. Participants underwent anamnesis, keratometry by NVISION-K 5001, subjective refraction by an optometrist, AL measurement by the Topcon MYAH biometer, and body height measurement. Spearman’s correlation test was employed to analyze the relationships between AL and keratometry, spherical equivalent, body height (Sperman’s correlation, all r ≥ 0.267, all p < 0.001), and age (Spearman’s correlation, p = 0.081). Subsequently, multiple regression analysis was conducted on the variables that demonstrated a previous correlation. The mathematical model obtained permits the estimation of AL based on average keratometry, spherical equivalent, and body height. This model is significant (p < 0.001) and explains 82.4% of AL variability.