Spherical Equivalent Prediction Analysis in IOL Power Calculations Using Eyetemis, A Comprehensive Approach

Purpose:To compare two different datasets, using Eyetemis, an online analytical tool designed for assessing the spherical equivalent prediction errors (SEQ-PE) of intraocular lens (IOL) power calculation formulas following cataract surgery.Setting:Institutional.Design:Retrospective case series.Methods:The study was comprised of two distinct datasets of patients who had undergone successful cataract surgery. Dataset-1 includes standard eyes whereas Dataset-2 includes eyes with keratoconus. An online tool was used for SEQ-PE analysis across the 2 datasets, adhering to ISO standards for evaluating accuracy based upon trueness and precision. The tool incorporates robust t-tests for comparing the trimmed-mean of the data, adjusting for heteroscedasticity. IOL constants in Dataset-1 were optimized for the comparison of Hoffer Q, Holladay1, SRK/T, Haigis and Barrett Universal II (BUII) formulas. In Dataset-2, IOL constants from the IOLCon website, were used for the comparison of the BUII and its designated KCN-version: Barrett TrueK Keratoconus (TrueK [KCN]).Results:For Dataset-1: the trimmed-mean SEQ-PE values of all formulas were not significantly different from zero. BUII had superior precision and accuracy compared to all other formulas except from Haigis (P≤ 0.04). For Dataset-2: BUII's trimmed-mean SEQ-PE was significantly different from zero (0.59D, P< 0.01), unlike the TrueK [KCN] (0.12D, P= 0.10). Additionally, TrueK [KCN] exhibited enhanced precision and accuracy relative to BUII (P< 0.01).Conclusions:The online analysis tool provides a streamlined approach for assessing the prediction accuracy of SEQ refraction following cataract surgery, effectively evaluating trueness, precision, and overall accuracy through the use of advanced statistical methods.