Abstract
Purpose :
To computationally assess the expected performance of a presbyopya correcting Intraocular Lens (PCIOL) in patients after LASIK surgery, in comparison with non-LASIK patients, and monofocal IOLs.
Methods :
Presbyopya correcting IOL (PCIOL, Alcon Acrysof IQ Vivity) and Monofocal IOLs (MonoIOL, Alcon Acrysof IQ) of 22-D power were virtually implanted in an eye model (corneal power 43 D, corneal spherical aberration (SA) of 0.28 mm for 6-mm pupil diameter, anterior chamber depth 3.2 mm). LASIK corneas for myopic (-7.5 to -2.5 D) and hyperopic (+2.5 to +4.5 D) pre-operative spherical error were modeled by inducing SA ranging from 1.15 to -0.78 um, correlated with the corrected pre-operative spherical error (Marcos et al. 2002).
Image quality was evaluated in terms of Visual Strehl (VS) at best focus and through-focus. In addition, a metric to quantify retinal image halos was estimated by convolving the Point Spread Function with a 2-arcmin pinhole and calculating the ratio of light beyond 2 arcmin, for 5-mm pupils, ranging from 0 to 1 (maximum halo). Calculations were performed using a commercial optical design software (OpticsStudio, Zemax) and Matlab.
Results :
For 5/3 mm pupil diameters VS @BestFocus was 0.93/0.99 and 0.78/0.52 for MonoIOL and for PCIOL (NoLASIK), and was 0.61±0.38 and 0.5±0.27 for MonoIOL and PCIOL (LASIK), on average (across LASIK conditions and pupils). VS at intermediate distances was 0.06/0.11 and 0.08/0.24 for MonoIOL and PCIOL (NoLASIK), and was 0.10±0.06 and 0.17±0.09 for MonoIOL and PCIOL (LASIK). The halo metric was 0.26 for MonoIOL and 0.64 for PCIOL (NoLASIK) and 0.59±0.32 for MonoIOL (LASIK) and 0.71±0.20 for PCIOL (LASIK). The impact of LASIK in combination with IOL on halos was largely asymmetric for hyperopic and myopic LASIK. For similar magnitude of pre-op LASIK refraction correction (+4.5 to -4.5 D), the average halo metric was 0.57±0.26 /0.85±0.04 for MonoIOL/PCIOL for hyperopic LASIK and 0.73±0.10/0.59±0.08 for Monofocal/Presbyopia for myopic LASIK.
Conclusions :
In (non LASIK) patients visual quality (VS) at best focus with a PCIOL lies within 16-18% of that with MonoIOL. However, the PCIOL outperforms the MonoIOL at intermediate distances (by 45-66%). The PCIOL performance is relatively immune to the presence of SA induced by LASIK. Furthermore, the PCIOL appears to interact favorably with positive SA (in myopic LASIK) to reduce halos.
This is a 2021 ARVO Annual Meeting abstract.