Effect of corneal topometric parameters on the accuracy of Panacea IOL calculator
First Author: D.Mingo-Botín SPAIN
Co Author(s): F. Castro Alonso N. Díaz de Guereñu
To evaluate the accuracy of a new method for intraocular lens (IOL) power selection that allows to incorporate corneal topometric measurements (asphericity and posterior/anterior corneal curvature ratio) in the calculation, compared to two well established formulas (SRK/T and Barrett Universal II).
Private practice, Madrid, and Ophthalmology Service, Alcañiz Hospital, Aragón, Spain.
Retrospective consecutive case series. Patients who had uneventful cataract surgery with implantation of an aspheric IOL (Tecnis ZCB00, Acrysof IQ SN60WF or Envista MX60) during 2019, and previous Lenstar biometry and Pentacam tomography, were included. Patients with previous corneal refractive surgery or poor quality of preoperative examinations were excluded. The predicted spherical equivalent was calculated using Panacea with and without taking into account asphericity and posterior/anterior corneal curvature ratio, SRK/T and Barrett Universal II formulas, and compared with the actual refractive outcome.
The study comprised 124 eyes of 94 patients. Standard deviation of prediction error (PE) and value of mean absolute prediction error (MAE), in order of lowest to highest, was Barrett Universal II (0.397 and 0.309 respectively), Panacea alone (0.389, 0.307), Panacea with asphericity consideration (0.390, 0.310), SRK/T (0.397, 0.309), Panacea with ratio (0.495, 0.371) and Panacea with asphericity and ratio (0.511, 0.384). After adjustment, the only statistically significant difference seen in MAE was between Barrett and Panacea with ratio and asphericity (p = 0.03). Panacea alone resulted in the highest percentage of eyes with PE between ± 0.5D (81.5%).
Incorporation of topometric parameters did not improve the predictive accuracy of the Panacea formula. Accuracy of Panacea IOL calculator without topometric parameters was comparable to Barrett Universal II formula.