Purpose: To investigate the optical performance and tolerance to misalignment of blue-light filtering monofocal intraocular lenses (IOLs).
Methods: The optical properties of two monofocal IOLs featuring yellow chromophores, CT Lucia 621 PY (Carl Zeiss Meditec AG) and Clareon CNA0T0 (Alcon Laboratories, Inc), were assessed in monochromatic and polychromatic light while introducing spherical aberration (SA). Optical quality metrics derived from the modulation transfer function were assessed after optimal IOL centration at 3- and 4.5-mm pupils. In addition, each IOL's tolerance to misalignment was examined by inducing up to 1 mm of decentration and the effect of tilting it by 5 degrees at 3 mm.
Results: The IOLs' resolution and contrast, while tested using a 3-mm aperture and an SA-neutral corneal model, indicated the CT Lucia 621 PY had a slightly higher modulation transfer function (MTF) at 50 lp/mm than the CNA0T0 under monochromatic conditions (0.77 vs 0.69). On introducing SA with (0.49 vs 0.40) and without (0.75 vs. 0.70) chromatic aberration, the CT Lucia 621 PY maintained its minimally better performance. When assessed with a 4.5-mm aperture in monochromatic light, the CT Lucia 621 PY displayed improved MTF with aberration-free cornea (0.71 vs 0.40) but performed worse after introducing SA (0.44 vs 0.62). However, both lenses achieved comparable MTF values under spherical and chromatic aberrations (0.28 vs 0.27). The IOL misalignment test revealed a better tolerance to tilt and decentration of the CT Lucia 621 PY across all conditions.
Conclusions: The CT Lucia 621 PY and CNA0T0 showed similar optical quality in different situations, with equal simulated distance visual acuity for both models. However, the CT Lucia 621 PY's aspheric design offers an advantage when dealing with often imperfect physiological conditions, displaying a more robust performance under tilt and decentration. [J Refract Surg. 2024;40(2):e79-e88.].