Study on glare phenomena and vision quality of a virtually implanted tunable liquid crystal IOL compared to monofocal and EDOF IOLs

Abstract

Purpose : Liquid crystal lenses have been proposed to be utilized as accommodative IOL (LC-IOL). Optical bench imaging properties are well characterized. However, no information exists on glare phenomena and perceived vision quality, especially for field gradient based designs without pixelization of electrodes. A central question is, whether the liquid crystals themselves act as scattering centers for bright light sources like car headlights, which would prevent their usage as IOL. Therefore, the goal of this study was to compare a LC-IOL with a monofocal and an EDOF lens using simulated implantation.

Methods : The study was conducted using a device named VirtIOL, mimicking the optical effects of a virtually implanted IOL into the subject’s eye. A dedicated model eye for the LC-IOL was developed. Here, the base refraction is accomplished by a monofocal IOL, while the add power is realized by the LC-IOL. This lens combination is compared to a monofocal and an EDOF IOL with mild glare. To obtain the subjective vision quality, 40 young healthy subjects had to sort the IOLs according to their best visual experience while looking at a night scenery on a display device in 6 m distance with a contextually integrated glaring white-light LED. The perceived angular glare sizes were obtained by having the subjects to adjust a circle to the perceived halo and starburst size. The subjective visual acuity and contrast sensitivity were determined by a FrACT-test.

Results : For mesopic distance vision, no significant difference was found in the subjective vision quality between the monofocal and the LC-IOL. Starburst size, halo size, contrast sensitivity, and visual acuity were also comparable for these two lenses. While the EDOF IOL achieved a similar visual acuity, it performed significantly worse in the other three disciplines and in the subjective vision quality.

Conclusions : The perceived vision quality using the LC-IOL and the monofocal IOL were comparable. The primary reason for this is that the LC-IOL is not using pixelization across its clear aperture. Regarding the initial question, we found that the LC-IOL does not induce glare phenomena like diffractive IOLs. The night vision performance is much better compared to EDOF or even multifocal IOLs. Summarizing, the investigated LC-IOL is a potential candidate for an accommodative lens implant using an electro-optical approach.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.