Visualization of Light Propagation with Multifocal Intraocular Lenses Using the Ouzo Effect.

Timo Eppig,Antonia Rawer,Achim Langenbucher,Kathrin Rubly

doi:10.1155/2019/6425040

Abstract

The number of presbyopia correcting intraocular lenses (IOLs) is increasing and new technologies are constantly emerging with the aim of correcting the loss of accommodation after cataract surgery. Various optical designs have been proposed to implement multifocality or an extended depth of focus (EDOF). Depending on the optical principle of an implanted lens, the visual performance often is deteriorated by superposition of individual image planes and halos of varying intensity. This experimental study presents a concept to visualize the light fields and especially the halos of mono- and multifocal IOLs using the well known alcoholic beverage “ouzo” in order to obtain qualitative data on the imaging characteristics. We conclude that ouzo is a useful, cost effective, and nonpolluting medium for beam visualization and an alternative to fluorescein or milk, which could find an application for educational purposes.

Highlights

Apart from monofocal intraocular lenses (IOLs) that generate a single focus in a specific distance, there are different ways to generate two or more foci by various optical principles
A quite new concept is implemented in the Tecnis5 Symfony5 IOL (Johnson & Johnson Vision, Santa Ana, USA), which is basically a diffractive multifocal IOL which aims to provide an extended depth of focus (EDOF) [3,4,5]
The superposition of the individual images and the unused light from higher diffractive orders cause formation of halos and a degradation of image contrast [10,11,12]. These halos are often reported by patients [10, 13] but still, many patients are satisfied with the visual performance of multifocal IOLs

Summary

Introduction

Apart from monofocal intraocular lenses (IOLs) that generate a single focus in a specific distance, there are different ways to generate two or more foci by various optical principles. A quite new concept is implemented in the Tecnis Symfony IOL (Johnson & Johnson Vision, Santa Ana, USA), which is basically a diffractive multifocal IOL which aims to provide an extended depth of focus (EDOF) [3,4,5] Other concepts such as refractive EDOF lenses [6], the light-sword lens [7], small aperture implants [8], and accommodating IOLs have been proposed [9]. The superposition of the individual images and the unused light from higher diffractive orders cause formation of halos and a degradation of image contrast (sometimes referred to as “waxy vision”) [10,11,12] These halos are often reported by patients [10, 13] but still, many patients are satisfied with the visual performance of multifocal IOLs. It is well known that visual performance with multifocal lenses improves within the first months after surgery due BioMed Research International

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Conclusion