VISUALIZATION OF LIGHT DISTRIBUTION AND RAY PROPAGATION IMAGING OF EXTENDED-DEPTH-OF-FOCUS IOLS

Extended depth of focus (EDoF) IOLs use different optical principals to enhance the range of vision and therefore differ in performance and side effects. We compared the light-distribution profiles and ray propagation of three EDoF IOL models and a monofocal IOL.

David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.

We compared the non-diffractive AcrySof IQ Vivity (Alcon Inc.) to the diffractive Symfony ZXR00 (Johnson & Johnson Vision) and AT Lara 829 MP (Carl Zeiss Meditec) in a laboratory investigation. The monofocal AcrySof IQ SN60WF (Alcon Inc.) served as a control. The point spread function (PSF) as a measure of spurious light was applied to assess the risk of photic phenomena. Each lens was submerged in a fluorescein solution and a 520-nm laser light was projected through the IOL. The emerging light was captured using a camera mounted on a microscope.

Evaluation of the PSF showed the lowest level of light spread for the monofocal IOL. The Acrysof IQ Vivity showed minimally extended light spread and both diffractive lenses showed excessive light intensity around the center of the PSF with several halo-like rings. The ray visualization and light intensity profile of the monofocal IOL revealed one distinct focus corresponding to the IOL nominal power, while the Vivity showed an elongated focus. For both diffractive EDoF IOL models we observed two foci for far and intermediate distance, with the Symfony demonstrating a slightly higher peak of the light intensity profile at the intermediate focus and the AT Lara showing far-dominance.

Ray propagation imaging confirmed an extended range of focus for all EDoF IOL models. Only the non-diffractive EDoF IOL showed a continuous elongated focus. The Vivity was associated with less spurious light in the PSF. This might translate to a lower level of photic phenomena in clinical use than with the diffractive lens designs.