Abstract
Purpose :
Estimation 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 utilized our recently developed see-through IOL telescope (IOL-T2) to measure the through-focus visual acuity with different IOL designs.
Methods :
The new IOL-T2 has a compact design and transfers the optical properties of the IOL correctly into the pupil plane of the eye (Lundström, Romashchenko, van der Mooren, Unsbo, Börjeson, Canovas, ARVO Invest. Ophthalmol. Vis. Sci. 2022;63(7):1802 – F0418). Four subjects (26 to 44 years of age) viewed a letter chart through the IOL-T2 with two different IOL designs of +20 D in optical power: one monofocal and one multifocal with an addition corresponding to +2.5 D in the spectacle plane. Trial lenses were placed in front of the telescope to measure the foveal through-focus visual acuity from +1 D to -4 D of defocus in 0.5 D steps. The testing was performed monocularly with 1% cyclopentolate to paralyze accommodation and an artificial aperture corresponding to 4.5 mm in entrance pupil diameter. The logMAR letter chart was placed at 3 m and the data was recalculated to compensate for the distance.
Results :
The through-focus visual acuity in logMAR of the subjects with the two IOL designs is shown in the figure (IOL-T2 S1, S2, S3, and S4) in orange, yellow, purple, and green. In blue is the corresponding clinical through-focus data on an older population implanted with the same two IOL models. The solid blue lines show the average visual acuity and the shaded blue regions the ±1 standard deviation for 130 and 72 subjects with the monofocal and multifocal IOL, respectively. The average visual acuity for distance with the IOL-T2 was -0.12 and -0.08 logMAR with the monofocal and the multifocal IOL, respectively, compared to -0.04 and -0.02 logMAR in the clinical data. At -2.5 D defocus with the multifocal IOL the IOL-T2 gave 0.11 logMAR, compared to 0.10 logMAR in the clinical data.
Conclusions :
The see-through IOL telescope IOL-T2 generates through-focus visual acuity data comparable to clinical measurements on patients with implanted IOLs. It is thereby a useful tool to compare the subjective experience through different IOL designs prior to implantation as well as to develop new IOL designs.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.