Impact Of Corneal High-Order Aberrations On Visual Performance With A Multifocal Intraocular Lens

To assess how corneal aberrations affect the visual performance of patients who have undergone implantation of the Multifocal Intraocular Lens (MIOL).

Qvision, Ophthalmology Department, Vithas Almería Hospital

A total of 270 individuals who had cataract surgery or refractive lens exchange and received the Liberty (Medicontur) MIOL were analyzed. The study examined the correlations between total high-order aberrations (HOAs), coma, trefoil, and spherical aberration (SA) measured with the Pentacam at a 4 mm pupil size and visual acuity, as well as contrast sensitivity areas under the defocus curves (AUC). Additionally, associations between other demographic and biometric factors and total AUCs were investigated.

Coma and trefoil aberrations in the eyes rarely exceeded 0.2 µm, with spherical aberration (SA) remaining below 0.1 µm and total higher-order aberrations (HOAs) staying under 0.3 µm. A significant correlation was observed between total HOAs and both age (rho = 0.32, p < 0.0005) and anterior chamber depth (rho = -0.21, p = 0.001). Among the examined factors, mesopic pupil size, age, and chart luminance, in that order, were most strongly associated with total AUCs. Adjusting for mesopic pupil size was necessary to reveal weaker correlations between AUCs and corneal aberrations, particularly for total HOAs and both total and near AUCs (p < 0.05).

Values under 0.3 µm for total HOAs, 0.2 µm for Coma and Trefoil, and 0.1 µm for spherical aberration at 4 mm are completely safe for the study IOL. Although higher values are uncommon, they may still be acceptable up to 0.5 µm. The 0.5 µm threshold at 4 mm for contraindication requires further investigation in relation to this and other IOLs but can be considered an adequate conservative point for MIOL contraindication. Exploring defocus curves for different levels of aberrations can be useful for managing patient expectations.