Theoretical Performance of Intraocular Lenses Correcting Both Spherical and Chromatic Aberration

Abstract

To assess the performance and optical limitations of intraocular lenses (IOLs) correcting both longitudinal spherical aberration (LSA) and longitudinal chromatic aberration (LCA) compared to standard spherical and aspheric IOLs. Using a set of 46 white light, pseudophakic eye models representing a population of cataract patients, retinal image quality was assessed for three IOL designs-standard spherical IOLs; aspheric IOLs, correcting a fixed amount of LSA; and aspheric refractive/diffractive IOLs, correcting a fixed amount of LSA and LCA. Depth of field and tolerance to IOL misalignments were also assessed. The improvement factor, based on the area under the radial polychromatic modulation transfer function (pMTF) curve of the IOL, correcting both average LSA and LCA over the aspheric IOL was 1.19±0.12, and over the spherical IOL was 1.43±0.29. Within the range of ±1.00 diopter of defocus, pMTF of the IOL correcting both LSA and LCA was equal or higher than both the spherical and aspheric IOLs. The IOL could be decentered up to 0.6 to 0.8 mm before the performance degraded below that of a spherical IOL. This is the first study that evaluates IOLs correcting both LSA and LCA in the presence of corneal higher order aberrations. Intraocular lenses that correct both LSA and LCA improve simulated retinal image quality over spherical IOLs and IOLs that correct LSA alone, without sacrificing depth of field or tolerance to decentration. Correction of LCA in combination with LSA shows the potential to improve visual performance.