Abstract
Purpose :
Starburst and halo are undesirable vision phenomena usually associated with the use of multifocal and EDoF IOLs, but it is not yet fully understood how they impact subjective quality of vision. The goal of the study was a qualitative and quantitative comparative analysis of different IOLs on their influence on night vision ability and photic phenomena using a virtual implantation method (VirtIOL).
Methods :
The study was conducted using a VirtIOL system, allowing the subjects to perceive a visual experience of a test IOL, mimicking the effect of an implanted IOL. A range of a monofocal, multifocal and EDoF IOLs was analyzed, which differ in add power and degree of chromatic correction. The study was divided into two parts: (1) qualitative analysis of vision and (2) quantitative analysis of the perceived angular dimensions of photic phenomena. (1) A display with a night scenery was placed in 6 m distance. Additionally a bright white-light LED was placed in accordance with the image context in front of a bright street light contained in the scenery (fig. 1). 48 subjects had to order the IOLs according to their best visual experience. (2) The subjects had to adjust the diameter of a displayed circle to match the perceived size of halo and starburst (fig. 2). This allows to calculate the angular subtense of the photic phenomena.
Results :
For mesopic distance vision the monofocal IOL was preferred over the multifocal and EDoF ones. For this lens starburst and halo size was found to be the smallest. However, we observed differences between the multifocal and EDoF lenses. Surprisingly the multifocal lens with the smallest starburst was found to have worst visual experience.
Conclusions :
Using a glare source in front of a suitable night scenery in combination with the VirtIOL and the size determination software, the described method helps to improve the understanding of different night vision phenomena and their relation to individual optical designs. It especially helps to evaluate, which configurations and appearances of photic phenomena are least bothering to the patient.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.