Optica

ORIGINAL ARTICLES

Optical Performance Measurement and Night Driving Simulation of ReSTOR, ReZoom, and Tecnis Multifocal Intraocular Lenses in a Model Eye
Junoh Choi, MS; Jim Schwiegerling, PhD
ABSTRACT
PURPOSE: To measure the optical properties of multifocal intraocular lenses (IOLs) for different pupil sizes. METHODS: An artificial eye was fabricated that had both the average sphericalaberration and chromatic aberration levels found in the human eye. This model eye contained a saline-filled wet cell into which various IOLs can be mounted. Pupil sizes of 3 and 6 mm were explored with the system. Using the model eye, the following IOLs were examined: Alcon ReSTOR apodized diffractive, AMO ReZoom zonal refractive, and Tecnis ZM900 full-aperture diffractive. The modulation transferfunction (MTF) for the lenses was calculated. The model eye was also used as a portable device to photograph nighttime driving scenes. RESULTS: For 3-mm pupils, the apodized and full-aperture diffractive IOLs balance contrast between near and distance vision, whereas the zonal refractive IOL performs poorly for near vision. For 6-mm pupils, the apodized diffractive shifts performance from near visionto distance vision, whereas the zonal refractive and full-aperture diffractive IOLs continue to balance performance between distance and near. Subjectively, the night driving photographs showed much more stray light artifacts for the zonal refractive and the full-aperture and apodized diffractive IOLs. CONCLUSIONS: Under dark conditions, the shift of optical performance of the apodized diffractivelens towards distance vision reduces artifacts that appear under night driving conditions. These artifacts remain for the zonal refractive and full-aperture diffractive lenses. [J Refract Surg. 2008;24:218-222.]

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ntraocular lenses (IOLs) are artificial lenses implanted into the human eye following cataract surgery. Although conventional monofocal IOLs provide good performance for distancevision, pseudophakes with these implants suffer from a lack of accommodation and consequently a severe degradation of uncorrected near vision. To compensate for this effect, multifocal IOLs have been introduced that provide simultaneous vision of both distant and near objects. Because multifocal IOLs produce multiple in- and out-of-focus images simultaneously on the retina, these lenses can improvenear vision at the expense of distance vision. We studied three different multifocal IOL designs, namely the ReSTOR (Alcon Laboratories Inc, Ft Worth, Tex), ReZoom (Advanced Medical Optic [AMO], Santa Ana, Calif), and Tecnis ZM900 (AMO). A model eye was developed to compare three IOLs at different pupil sizes. With the model eye, polychromatic modulation transfer function (MTF) is measured, and anighttime driving scene is photographed. MATERIALS AND METHODS The morphology of human eyes varies markedly from person to person. To study IOLs in a model eye, the model should mimic the structure and optical performance of the average human eye. Therefore, it is critical to have a model eye follow acceptable parameters to more accurately test the performance of the IOLs. Our model eye wasdesigned to meet three major design parameters: vergence at the IOL plane, corneal spherical aberration, and ocular chromatic aberration. These criteria were met with appropriate choices of powers and material for the artificial cornea in the model eye. The verFrom the College of Optical Sciences, Department of Ophthalmology, University of Arizona, Tucson, Ariz. The authors have no proprietary interestin the materials presented herein. Dr Schwiegerling receives grant and travel support from Alcon Laboratories Inc, Ft Worth, Tex. Correspondence: Jim Schwiegerling, PhD, Dept of Ophthalmology, 655 N Alvernon Way, Ste 108, Tucson, AZ 85711. Tel: 520.661.6504; E-mail: jschwieg@u.arizona.edu Received: July 16, 2007 Accepted: December 12, 2007

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