Abstract
Purpose :
Multifocal contact lenses (MCLs) have been proposed as a myopia control therapy. In this study, we assessed through-focus visual performance and accommodative response in both emmetropic and myopic subjects viewing through novel myopia control optical designs using an adaptive optics visual simulator (AOVS).
Methods :
Diffractive MCLs designed by Clerio Vision (USA) were simulated in a custom AOVS equipped with a spatial light modulator (Pluto-Vis Holoeye, USA). The optical test conditions (TCs) consisted of a 4-mm diameter central plano optical zone for distance, and 4 segmented peripheral regions containing pure defocus (TC1), astigmatism and coma (TC2), a combination of defocus, astigmatism and coma (TC3), and a single vision control (SV). Ten myopic (M; SE: -2.00 to -6.25 D) and 6 emmetropic (E; SE: +0.25 to +0.75 D) subjects participated in the study (cyl <0.5 D both groups, age: 25.4±1.1 years). A digital micromirror device (DMD) monochromatically illuminated (555nm) was used to assess monocular visual performance (TF high contrast visual acuity with natural viewing conditions). Accommodative lags were estimated from the response to 0-5 D accommodative demands (AD) measured with Hartmann-Shack aberrometry and subsequent TF image quality metric computation.
Results :
Best-corrected logMAR VA was -0.11±0.02 for SV, and was minimally affected by MCL designs -0.08±0.03 (TC1), -0.07±0.04 (TC2) & -0.05±0.04 (TC3). Pupil diameter was on average 8% larger, decreased at a lower rate with AD in myopes than emmetropes (-0.34 and -0.21, respectively, 0-2 D range), and decreased at a faster rate with MCLs (-0.39 & -0.33 mm/D, MCLs on average, in M). The average accommodative lag with SV in M/E was 0.66/0.53D & 1.39/0.96D at 3 & 5 D of AD, respectively. TC1 decreased accommodative lag to 0.46/0.3 D at 3 D of AD, while TC2 and TC3 did not affect lags.
Conclusions :
Visual quality at intermediate/near, pupil dynamics & accommodative response differed between emmetropes and myopes, and they were influenced by MCL designs. A segmented design with 4 peripheral defocusing areas improved accommodative response in myopes, without compromising distance vision. Visual simulators allow for understanding the interplay of physiological and lens design factors, guiding and customizing MCLs for myopia control.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.