Numerical Analysis of the Effect of Decentered Refractive Segmented Extended Depth of Focus (EDoF) Intraocular Lenses on Predicted Visual Outcomes

Abstract

This study aimed to evaluate the optical performance of a rotationally asymmetric intraocular lens (IOL) when it is decentered relative to the visual axis. The FEMTIS Comfort IOL (Teleon Surgical B.V., Spankeren, The Netherlands) was assessed using ray tracing software in the Atchison model eye at apertures of 3.0 mm and 4.5 mm. The metric used for assessment was the through-the-focus area under the modulation transfer function (TF-MTFa). Decentrations of 0.2 mm and 0.4 mm were considered. Our results indicated that the MTFa defocus curves exhibited significant differences depending on the direction of vertical decentration. Downward decentrations shifted the MTFa curve towards virtual vergences, resulting in improved optical quality at far distances but decreased optical quality at intermediate and near vision. Conversely, upward decentrations produced the opposite effect. Since, on one hand, this lens is fixed within the capsulorhexis during surgery, demonstrating excellent stability, and on the other hand, the precise centration of the capsulorhexis can be made accurately off the visual axis, these results provide surgeons with the opportunity to plan various clinical scenarios to optimize surgical outcomes with this IOL by selecting the optimal location for capsulorhexis centration in each patient.