Enhanced Depth of Focus Intraocular Lenses: Through Focus Evaluation of Wavefront-Shaping versus Diffractive Optics

A new class of nondiffractive, wavefront-shaping Enhanced-Depth-of-Focus (EDoF) IOLs has been introduced very recently to cope with photic phenomena known from diffractive EDoF IOLs. We investigated the through focus modulation transfer function (MTF) of two wavefront-shaping EDoF IOLs compared to an established diffractive EDoF IOL on the optical bench. Such comparison on the optical bench had not been performed before and is of high clinical importance for the cataract surgeon.

Tecnis Symfony (diffractive) and the wavefront-shaping Acrysof IQ Vivity and LuxSmart Crystal IOLs (22 D each) were assessed by the OptiSpheric IOL PRO 2 imaging test bench with an ISO-2 cornea and a wavelength of 546 nm. Apertures of 3 mm and 4.5 mm were applied.

For all three IOLs, two peaks showed up in the through focus MTF curves representing the primary and secondary focus. For Symfony, these peaks were most distinct. Power difference between far and intermediate focus was 1.25 D (Symfony), 1.75 D (Vivity), and 1.5 D (LuxSmart) with an aperture of 3 mm. With an aperture of 4.5 mm, only for LuxSmart, power difference diminished slightly to about 1 D, and only the MTF in the intermediate focus decreased for all lenses.

For all three IOLs, we could confirm a considerable depth of focus that was most extended for Vivity. Both new wavefront-shaping IOLs had lower values of peak MTF but a markedly more continuous through focus behavior compared to the diffractive EDoF IOL.