Accuracy of Intraocular Lens Calculations in Infants and Children Undergoing Cataract Surgery

Abstract

We sought to evaluate the accuracy of intraocular lens calculations in children undergoing cataract extraction with intraocular lens (IOL) implantation. This was a retrospective review of 101 consecutive cases of pediatric cataract extraction with posterior chamber IOL. Median age at the time of surgery was 4.8 years, and 23 of the children were younger than 2 years of age. Initial IOL calculations were made using either the SRK II or SRK T formulas. Preoperative predictive data were compared with the refractive result obtained at the 2-month postoperative visit. Prediction error was calculated for each patient, and lens calculation errors were back-calculated for each of 4 commonly used IOL calculation formulas, including the SRK II, SRK T, Holladay I, and Hoffer Q. The mean prediction error for all patients was 0.30 D. Despite this level of overall accuracy, significant variability did occur with outcomes ranging from -4.06 D to + 3.86 D of the desired spherical equivalent. Mean absolute prediction error was 1.16 D with no significant difference between the SRK II and SRK T formulas. Lens calculation errors predicted by each of the 4 formulas studied demonstrated a high degree of variability with the SRK II being the least variable and the Hoffer Q being the most variable, particularly among the youngest group of children with the axial lengths less than 19 mm. The accuracy of commonly used IOL calculation formulas is generally reasonable but highly variable within the pediatric population, Newer theoretic IOL calculation formulas did not outperform older regression models.