Multiformula Prediction Range: a univariate predictor of IOL Power Calculation Accuracy.

Abstract

Purpose: The purpose of this study was to evaluate the influence of range between the predictions of 5 different calculation formulas in IOL power calculation accuracy.

Settings: General University Hospital of Elche, Spain.

Design: Retrospective Sequential Cohort.

Methods: In this retrospective sequential cohort, the LenStar LS900 (Haag-Streit, Koeniz, Switzerland) was used for the preoperative biometry. The predicted spherical equivalent refraction of the implanted IOL were calculated for 5 different formulas: Barrett Universal II, Emmetropia Verifying Optical (EVO) 2.0, Hill RBF-3.0, Kane, PEARL-DGS. Multiformula Prediction Range was defined as the range of the refractive error predicted by the 5 formulas. According to the median of the Multiformula Prediction Range the sample was divided into a low and high spread group (LS and HS respectively).

Results: 278 eyes were included. The standard deviation of the prediction error was significantly lower in the LS group for all included formulas. For the Barrett Universal II, EVO 2.0, RBF-3.0, Kane and PEARL-DGS formulae, the median absolute error (MdAE) was significantly lower in the LS group compared to the HS group (p-values of 0.001, 0.027, 0.004, 0.028 and 0.035, respectively). The percentage of eyes within the ±0.50D PE range was significantly higher in the LS group for all five analyzed formulas.

Conclusions: Multiformula Prediction Range can be a novel univariate predictor of IOL power calculation accuracy and a potential determinant for identifying patient suitable for immediate sequential cataract surgery. Accuracy was consistently higher for all five included formulas in the Low Spread group.