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Purpose: To describe a case of refractive lens exchange with multifocal intraocular lens implantation in a 52-year-old woman with emmetropic presbyopia who had near glasses and contact lens intolerance after acquired nystagmus., Methods: Preoperative corrected distance visual acuity was 20/25 in the right eye, 20/20 in the left eye, and 20/20 binocularly. Corrected near visual acuity was 20/30 in the right eye and 20/20 in the left eye, reaching 20/20 binocularly but showing unsatisfactory binocular vision with asthenopia and intolerance to prolonged reading. The surgical plan entailed bilateral implantation of multifocal intraocular lens., Results: Three months postoperatively, uncorrected distance visual acuity was 20/20 in the right eye and 20/20 in the left eye, reaching 20/20 binocularly. Monocular and binocular uncorrected near visual acuity of 20/20 was achieved without symptoms of asthenopia in prolonged reading. There were no changes in nystagmus characteristics after surgery., Conclusions: Multifocal intraocular lens implantation to manage a case of clinically significant acquired nystagmus may be a safe alternative, especially if others options have failed., (Copyright 2013, SLACK Incorporated.)

Purpose: To evaluate the optical quality of Acrysof Restor SN6AD1 refractive-diffractive +3.00 D and Lentis Mplus LS-312 nonrotational symmetric +3.00 D aspheric multifocal intraocular lenses (IOLs) and analyze the effect of tilt and decentration., Setting: University of Valencia, Valencia, and University of Murcia, Murcia, Spain., Design: Experimental study., Methods: An artificial model eye was used to measure wavefront aberrations of both IOL models. The modulation transfer function (MTF) and point-spread function (PSF) were calculated for a 5.0 mm pupil and under 5 situations: centered, 0.2 mm and 0.4 mm decentered, and 2 degrees and 4 degrees tilted., Results: The refractive-diffractive IOL had the highest MTF values at all spatial frequencies. Similarly, the PSF was worse for the refractive-diffractive IOL. The MTFs for the refractive-diffractive IOL decreased when the IOL was decentered or tilted, being more robust for tilting than decentration. The MTFs for the nonrotational symmetric IOL were similar under all testing conditions. Cutoff frequencies for the refractive-diffractive IOL were stable over the range of tilting studied and comparable with the cutoff when the IOL was centered (approximately 50 cycles per degree [cpd]). When the IOL was decentered, the cutoff frequency decreased by approximately 40 cpd. The nonrotational symmetric IOL cutoff frequencies for misalignment and tilt were low (approximately 30 cpd) and similar under all conditions., Conclusions: The refractive-diffractive IOL provided better optical quality than the nonrotational symmetric IOL. Tilt and decentration had a significant impact on optical quality with both IOLs, being more severe with the nonrotational symmetric IOL., (Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the theoretical effect of an increase in the negative Q-factor (hyperprolateness) on the refractive state and its effect on presbyopia treatment., Methods: Ray tracing software was used to simulate the Navarro eye model. To simulate refractive therapy, corneal Q-factor ranged from 0 to -1.50. Refractive state of the model eye was defined as the target vergence required to maximize retinal image quality according to several image quality metrics. The change of refractive state produced by pupil constriction from 6 to 2 mm was estimated., Results: For 0 ≥ Q ≥ -0.6, spherical aberration of the model eye is positive, therefore, pupil miosis causes a hypermetropic shift in refractive state. Over the range -0.6 ≥ Q ≥ -1.5, spherical aberration becomes negative and pupil constriction causes the eye's far point to approach the eye, inducing a myopic shift. A maximum 0.60-diopter myopic shift in refractive state due to pupil constriction occurred for Q=-1.25., Conclusions: Optical modeling predicts that surgically induced negative corneal Q-value will produce a change in the refractive state of the eye after pupillary miosis., (Copyright 2012, SLACK Incorporated.)