Axial length and corneal curvature of normal eyes in the first decade of life

Background/Aims To establish normative curves for axial length and corneal curvature in the first decade of life. Methods This is a cross-sectional study from a single institution in the United States. Children from 0- to 10-years of age with no underlying ocular pathology were prospectively enrolled to obtain ultrasound biometry and hand-held keratometry while under anaesthesia for an unrelated procedure. Older cooperative children had optical biometry obtained in-office. Logarithmic quantile regression models were used to determine the change in axial length and average keratometry as a function of age. Results Single-eye measurements from 100 children were included. 75% of children were White and 49% female. Median axial length ranged from 20.6 mm (IQR, 20.2 to 21.1 mm) at age one year to 23.1 mm (IQR, 22.5 to 23.8 mm) at age ten years. Median average keratometry ranged from 44.1 D (IQR, 42.6 to 45.4 D) at age one year to 43.5 (IQR, 42.2 to 44.0 D) at age ten years. As age increased, there was a significant increase in axial length (0.74 mm per doubling of age; 95% CI, 0.62 to 0.82 mm), and a non-significant trend towards lower average keratometry (-0.21 D per doubling of age; 95% CI, -0.62 to 0.08 D). Conclusions We provide a set of normative charts for axial length and corneal curvature which may facilitate the identification of eyes outside the normal range and assist in the management of ocular conditions such as glaucoma or cataract.