Abstract
Purpose :
Evaluation of the subjective visual experience through intraocular lenses (IOL) prior to implantation is important both for patient satisfaction and for optimizing the optical design of the IOL. In this work we have designed a compact see-through IOL telescope (Type 2, IOL-T2) that can transfer the scattering as well as other optical properties of the IOL correctly into the pupil plane of the eye.
Methods :
The objective of the IOL-T2 consists of a +45 D camera objective and the +20 D IOL in a water cuvette that together have an effective power of +40 D. The intermediate image can then be viewed by a +40 D eyepiece, thus generating a telescope with angular magnification of -1. The eyepiece also serves the purpose to, together with the cornea of the observer, image the IOL into the pupil plane with both the angular and the transverse magnification equal to -1. As a proof of concept, the IOL-T2 was used to evaluate the foveal contrast sensitivity (CS) with and without a glare source for one monofocal and two multifocal IOLs in three subjects. The glare source was located in the 2.5° nasal visual field of the right eye and gave 1 lux at the level of the IOL telescope. The average luminance of the screen was 50 cd/m2.
Results :
The grating resolution CS at 7.5 cycles/degree was reduced with the multifocal IOLs compared to the monofocal design. No statistically significant difference was found between the +2.75 D and the +4.00 D addition. The glare source induced additional decrease in CS, but the reduction varied between individuals and was larger for the monofocal design than the multifocal designs.
Conclusions :
The new IOL-T2 has a compact design and transfer all optical properties of the IOL correctly into the pupil plane of the eye. It is thereby a useful tool to compare the subjective (and the objective, see separate abstract) experience through different IOL designs prior to implantation as well as to develop new IOL designs.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.