Simulation of daily soft multifocal contact lenses using SimVis Gekko: from in-vitro and computational characterization to clinical validation

Abstract

Abstract Multifocal contact lenses (MCLs) are one of the solutions to correct presbyopia, but their adoption is not widespread due to factors such as discomfort, lack of awareness, a lengthy fitting process and/or unexpected visual performance. To address this situation, visual simulators can be used to aid in refining the adaptation process. This study aims to obtain accurate simulations for a novel visual simulator (SimVis Gekko; 2EyesVision, Spain) of various daily commercial soft MCL designs from four different manufacturers: Dailies Total1 (Alcon), MyDay (Coopervision), 1Day Acuvue Moist (Johnson & Johnson) and Biotrue ONEday (Bausch + Lomb). In-vitro characterization of these MCLSs -for several distance powers and additions- was obtained using a NIMO TR-1504 instrument (Lambda-X, Belgium). From the averaged relative power profiles across distance powers, phase maps were reconstructed and Through-Focus Visual Strehl (TFVS) metric was calculated for each MCL design considering different optical diameters. The SimVis Gekko simulation corresponding to each MCL design and pupil diameter was obtained computationally and validated on bench. Finally, the MCL simulations were clinically validated in a pilot study involving presbyopic patients with different refractive errors and additions. The results of the clinical validation show a good agreement between the SimVis Gekko simulations and the real MCLs (for all the designs) when measuring through-focus visual acuity (TFVA) curves and VA at three real distances. All MCL designs showed a partial correlation (rxy,z) higher than 0.90 and a Root Mean Square Error (RMSE) below 0.07 logMAR between the TFVA of SimVis Gekko simulations and Real MCLs across subjects. The validity of the simulation approach using SimVis Gekko and using experimental measurements obtained with Nimo TR-1504 was therefore confirmed by the clinical results obtained in this study, what opens the possibility of using this visual simulator to assist and speed up the fitting process of MCLs.