Abstract
Purpose :
Positive dyshotopsia (PD) (such as halo, glare, starburst) is one of the main drawbacks of intraocular lenses (IOLs) for presbyopia correction. Adequate assessment of these effects before lens implantation is a valuable tool for both analysis and improvement of currently available IOL designs. This task is non-trivial and can be done by means of different optical setups. In this work we evaluate and compare two see-through setups, designed for simulations of the physical IOL-related visual symptoms.
Methods :
Two IOL telescopes, Type 1 (IOL-T1) and Type 2 (IOL-T2) (devices are reported in two separate abstracts), have been objectively compared in their ability to translate visual symptoms from an IOL to an observer. In these systems, an IOL is part of the main ray path, which allows to study PD induced by an actual manufactured IOL.
Each setup was evaluated with three different IOL designs: one monofocal, and two multifocals with 2.75 D and 4.00 D add power respectively. All three IOLs had the same base power. A camera was used in place of an observer, and a central glare source was imaged against a black background. The analysis was performed on high dynamic range images obtained from combining several frames (RGB converted to monochrome) with different exposure times.
Light scatter data from literature is used as basis for comparison of the level and the field location of the halo of multifocal IOLs.
Results :
In both setups, the recorded radial-average scatter function allows to clearly identify the multifocality-related halos and distinguish between the higher- and lower-add IOLs. The scatter levels of monofocal and multifocal IOLs were comparable with earlier reported data (Langeslag et al. JCRS 2014) The location of the IOL-related PD peaks is similar between the two devices and resides below 0.4° in field angle. This is comparable with previously reported theoretical prediction of 0.33° for a 4.00 D add power multifocal IOL (Van der Mooren et al. IOVS2016).
Conclusions :
This study compares objectively the PD measured with two see-through setups designed to evaluate actual IOLs. The results show that IOL-T1 and IOL-T2 perform similarly and show data comparable to published pre-clinical data for different IOL designs, allowing objective assessment of PD. Subjective testing with these devices is out of the scope of this work and is reported in two separate studies.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.