Accuracy of Intraocular Lens Calculation in a Non-diffractive Extended Depth of Focus Intraocular Lens After Myopic LASIK.

Purpose: To evaluate intraocular lens (IOL) power calculation of a non-diffractive extended depth of focus (EDOF) IOL after myopic laser in situ keratomileusis (LASIK) without historical data.

Methods: In this consecutive case series, patients who had undergone lens surgery with implantation of a non-diffractive EDOF IOL after myopic laser in situ keratomileusis (LASIK) at the Department of Ophthalmology, University Hospital Frankfurt, Frankfurt, Germany, were included. Preoperative assessments included biometry and tomography using Scheimpflug technology (Pentacam; Oculus Optikgeräte GmbH). Seven IOL calculation formulas for use in eyes after myopic LASIK have been analyzed: Potvin-Hill-Shammas-PM, OKULIX ray-tracing, PEARL-DGS and PEARL-DGS with posterior radial curvature, Barrett True-K No History with measured and predicted posterior corneal astigmatism, Hoffer QST, and EVO 2.0. The last three formulas were additionally calculated using the European Society of Cataract and Refractive Surgery (ESCRS) online calculator. Spherical equivalent prediction errors were analyzed using an established online tool (Eyetemis).

Results: Thirty-four eyes of 34 patients were enrolled. Trueness of all formulas was high, with no significant difference from zero, except for OKULIX ray-tracing (-0.40 ± 0.60, < .01). No statistically significant differences in accuracy were found, with more than 59% of eyes within ±0.50 diopters and more than 85% within ±1.00 diopters for all formulas. Similar results were found between the formulas included in the ESCRS calculator when using the recommended IOL constants or constants from the IOLcon database.

Conclusions: A comparison of ray-tracing with other IOL calculation formulas revealed no substantial advantage for the former, resulting in comparable outcomes. Using the ESCRS calculator yielded comparable good results.