gms | German Medical Science

Purpose: To evaluate ray-tracing for intraocular lens (IOL) calculation of a non-diffractive wavefront-shaping extended depth of focus IOL after myopic laser in-situ keratomileusis (LASIK).

Methods: In this retrospective, consecutive case series, we included patients in the Department of Ophthalmology, Goethe-University, (Frankfurt, Germany) after cataract surgery with implantation of a non-diffractive wavefront-shaping extended depth of focus (EDoF) IOL (AcrySof IQ Vivity, Alcon) with a history of myopic LASIK. Preoperative assessments included biometry (IOLMaster 700, Carl Zeiss Meditec), as well as corneal tomography (Pentacam AXL, Oculus Optikgeräte GmbH). The mean prediction error (MPE), mean and median absolute prediction error (MEA and MedAE), and the number of eyes within ±0.50, ±1.00, and ±2.00 diopters (D) were compared.

Results: The study comprised thirty-six eyes of twenty-four patients. The best performing formulas ranked on the MedAE were the Potvin-Hill Shammas PM formula (0.22 D), followed by OKULIX ray tracing (0.26 D), EVO 2.0 (0.29 D), Barrett True K no history (BTK) with measured posterior corneal astigmatism (mBTK) (0.32 D), Hoffer QST (0.33 D), Pearl DGS (0.34 D), Haigis-L (0.44 D), and BTK with predicted PCA (pBTK) (0.81 D). Except for the pBTK, no statistically significant differences in the absolute prediction errors of the ray tracing calculation compared to the six other formulas were found. EVO 2.0 and Potvin-Hill Shammas PM showed the most eyes within ±0.5 D.

Conclusion: The most accurate predictions of the actual postoperative refraction in patients who had myopic LASIK were achieved using the Potvin-Hill Shammas PM formula and OKULIX ray tracing in terms of MedAE, and the EVO 2.0 formula in terms of percentage within target refraction.