Purpose:
To study the optical performance of different intraocular lenses (IOLs) inside the human eye in order to ascertain the influence of multifocality’s technology and its relation with the pupil size.
Methods:
The study included 30 eyes (10 eyes for each type: monofocal Acrysof, multifocal diffractive ReSTOR and multifocal refractive Rezoom). The intraocular optical quality was characterized for 3 and 5 mm pupils by means of the difference between total and corneal aberrations measured three months after surgery. When making the subtraction, both maps were referred to the pupil center and the conditions of illumination are the same for both measures. Our software allows to introduce the off-set between maps in order to introduce a realignment algorithm in the calculations of the difference. The main outcomes measures were intraocular aberrations (RMS value), Modulation Transfer Function (MTF) values, Point Spread Function (PSF) and Strehl ratio.
Results:
The refractive multifocal Rezoom showed higher intraocular aberrations than the diffractive ReSTOR and standard monofocal (p = 0.022) (Figure 1. Comparative maps of the intraocular wavefront of the 3 IOLs for 3 mm (Top) and 5 mm (Center) pupil diameters. Bottom: E-Snellen simulation considering the total ocular aberrations for 5 mm pupil diameter). The difference in spherical aberration between ReSTOR and Rezoom were statistically significant for 5 mm (p = 0.003) and for 3 mm pupil (p = 0.001). There were no statistically significant differences for coma aberration between IOLs (p = 0.185) for 3 mm, and, for 5 mm pupil, the ReSTOR showed the lower values (p = 0.012).
Conclusions:
Multifocal refractive intraocular lens showed higher intraocular aberrations. The increase of optical aberrations when the pupil is enlarged from 3 to 5 mm was compensated by the hybrid design of the refractive-diffractive IOL.
Keywords: intraocular lens • optical properties • presbyopia