Abstract
Purpose: :
To assess the influence of an apodized diffractive intraocular lens (IOL) designed for presbyopia correction on postoperative higher–order aberrations in patients undergoing cataract surgery.
Methods: :
ReSTOR® apodized diffractive IOLs were implanted in 23 eyes undergoing routine cataract surgery. In the 10 myopic eyes, the mean preoperative spherical equivalent (SE) refraction was –2.3D±1.4D, and in the 13 hyperopic eyes the mean preoperative SE was +1.8D±1.0D. Axial length (AL) was measured with the IOL Master®, a device that determines the AL in the visual axis and whose measurements are not influenced by probe angle or by the examiner. Keratometry values were derived from corneal topography, using about 4000 measurement points located in the pupillary area (mean pupillary power). When using the apodized lens it is essential that visual axis, pupillary center and IOL center are matched. Accordingly, after uncomplicated procedures (temporal limbal incision, sutureless), centration of the IOL in the bag was followed by the injection of a miotic and the subsequent alignment of the IOL rings with the 3–4 mm miotic pupil.
Results: :
3 months after surgery, mean postoperative SE for the myopes was –0.45D±0.6D and for the hyperopes –0.02D±0.2D. All eyes were able to read J3 without correction. In a typical eye, postoperative total higher–order aberrations were recorded at 0.288µ, postoperative coma at 0.070µ and postoperative spherical aberrations at 0.042µ. In contrast, postoperative total high–order aberrations after the implantation of a monofocal IOL (Acrysof®) in comparable eyes were registered at 0.631µ, coma at 0.118µ and spherical aberrations at 0.073µ. There were no complaints of postoperative glare, halos or ghosting in the eyes with the apodized IOL.
Conclusions: :
Compared to a monofocal IOL, the apodized diffractive IOL appears to improve postoperative optical quality by generating lower levels of higher–order aberrations. Moreover, in this small group of eyes, in addition to correcting presbyopia, the apodized IOL seems to produce none of the subjective visual problems seen in other diffractive or in multifocal presbyopic lenses.
Keywords: intraocular lens • presbyopia • refractive surgery