Effect of Decentration on Aberrometric Profile of Rotationally Asymmetric Acunex Intraocular Lenses

The optical performance of rotationally asymmetric multifocal intraocular lenses (IOLs) may be especially vulnerable to decentration due to their non-rotationally symmetric refractive design. This study explores the effect of controlled decentration of IOLs on the aberrometric behavior of low-addition and high-addition Acunex IOLs. Both IOLs were evaluated on an optical bench using the NIMO system in centered position and under induced decentrations of 0.5 mm and 1.0 mm applied in horizontal and vertical directions. Average Zernike coefficients were analyzed for two apertures intended to represent smaller and larger pupil conditions. Both lenses showed similar aberrometric profiles under centered conditions and for the smaller aperture. However, with increasing decentration, the larger aperture revealed evident direction-dependent performance. The induced changes followed structured patterns that differed by magnitude and direction of decentration. The most noticeable variations were observed in asymmetric aberrations, particularly coma-related, while spherical aberration also changed under specific displacements. Although both IOLs shared similar trends, their responses differed, suggesting that the addition profile may influence decentration tolerance. Controlled decentration produces measurable, direction-dependent changes in the aberrometric profile of rotationally asymmetric Acunex IOLs, especially for larger aperture.