The accuracy of intraocular lens calculation varies by age in the Infant Aphakia Treatment Study

Abstract

Refraction predictions from intraocular lens (IOL) calculation formulae are inaccurate in children. We sought to quantify the relationship between age and prediction error using a model derived from the biometry measurements of children enrolled in the Infant Aphakia Treatment Study (IATS) when they were ≤7 months of age. We calculated theoretical predicted refractions in diopters (D) using axial length, average keratometry, and IOL powers at each measurement time point using the Holladay 1 formula. We compared the predicted refraction to the actual refraction and calculated the absolute prediction error (APE). We found that the median APE was 1.60 D (IQR, 0.73-3.11 D) at a mean age (corrected for estimated gestational age) of 0.20 ± 0.14 years and decreased to 1.11 D (IQR, 0.42-2.20 D) at 10.60 ± 0.27 years. We analyzed the association of age with APE using linear mixed-effects models adjusting for axial length, average keratometry, and IOL power and found that as age doubled, APE decreased by 0.25 D (95% CI, 0.09-0.40 D). The accuracy of IOL calculations increases with age, independent of biometry measurements and IOL power.