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Copyright of Journal of Optometry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This manuscript aims to evaluate the tolerance to rotation of a toric monofocal and a toric bifocal intraocular lenses with different cylinder powers. Theoretical designs based on wavefront aberrations were created to simulate a toric monofocal and a toric bifocal intraocular lens. Cylinder power ranged from −1 D to −6 D, in steps of −1 D. Tolerance to rotation was estimated by the visual Strehl ratio based on the optical transfer function (VSOTF) metric. Tolerance to rotation for both monofocal and bifocal intraocular lenses decreased when the cylinder power increased. For the bifocal design studied, the tolerance to rotation was larger for the near focus than for the far, however the overall quality was poorer for the near focus. Our findings show evidence that rotation tolerance depends both on the design of the intraocular lens and the cylinder power. This approach could be useful for predicting the tolerance to rotation of monofocal and multifocal toric intraocular lenses prior the surgery. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the repeatability of an optical device (NIMO TR1504, Lambda-X, Belgium) for measuring multifocal contact lens power profiles. Methods The NIMO TR1504 was used to measure power profiles 30 times for each of 10 different contact lenses from 4 major companies. All contact lenses were labelled as −3 D for distance vision; half were for high addition and half for low addition. The optical zone in all measurements was set to 3-mm radius. For each lens, the median power profile and the residuals of the 30 measurements were calculated. The 95% confidence bands and two indices that summarize measurement errors were calculated: the repeatability limit and an index of repeatability heterogeneity, quantifying heterogeneity of measurement errors over the optical zone. Results The repeatability limit was good (from 0.04 D to 0.12 D), for all multifocal contact lenses. Variability of measurement errors of power profiles was quite homogeneous along the optical zone for all lenses, although for some lenses variability was slightly higher in the centre than peripherally. Conclusions The repeatability of measured power profiles obtained by the NIMO TR1504 is lower than 0.12 D for the multifocal contact lenses. [ABSTRACT FROM AUTHOR]

Purpose To assess the effect of different disposable soft contact lenses upon corneal thickness, and upon anterior and posterior corneal curvatures using a dual-Scheimpflug imaging based device. Methods Twenty-eight young, healthy subjects wore four different types of daily disposable soft contact lenses on four different days: Dailies Total1, Proclear 1 Day, Clariti 1-Day and 1-Day Acuvue Moist. The lenses had different material and water content. Pachymetry maps and keratometry values were obtained using the Galilei G4 twice a day: one before putting the lens on and one after an eight-hour period of contact-lens wear. Measurements were also recorded without any contact lenses being worn during a day. Results Clariti 1-Day lens caused the greatest thickening in the central (8.9 ± 2.8 μm; p < 0.01) and in the peripheral cornea (10.1 ± 4.6 μm; p < 0.01), whereas Dailies Total1 was the lens that had the most similar behaviour to the non-contact lens scenario. All the lenses caused a slight flattening in the anterior corneal curvature, except Clariti 1-Day, which induced a very slight steepening. The four lenses caused a steepening of different magnitude in the posterior corneal curvature. Conclusions The magnitude of the changes introduced by the use of soft contact lenses over the eight-hour wearing period was rather small. Thus it is probable it will not influence the vision nor the comfort of the subject. Also, variations on corneal parameters seem to depend on the type of contact lens used. [ABSTRACT FROM AUTHOR]

Purpose: To study the effect of simulated amblyopic and normal higher-order aberrations on visual performance of normal eyes. Methods: To assess visual function, an adaptive optics visual simulator was used to compensate volunteers' ocular aberrations and simulate the wavefront aberration patterns found in healthy and amblyopic eyes in 7 healthy individuals. Visual acuity for high (100%), medium (50%), and low (10%) contrast and contrast sensitivity at 10, 20, and 25 cycles per degree (cpd) were measured after simulation of both pattern aberrations. The modulation transfer function and the point spread function were computed based on the aberration data. All measures were taken for 3 and 5.5 mm pupil sizes. Results: No statistically significant differences in visual acuity and contrast sensitivity were found between both groups for any analyzed contrast level, spatial frequency, and pupil size values. Mean logMAR visual acuity for a 3 mm pupil was −0.11 ± 0.04 for 100% contrast levels, −0.06 ± 0.06 for 50%, and 0.17 ± 0.07 for 10%. For a 5.5 mm pupil, the values were −0.06 ± 0.04 (100%), 0.00 ± 0.05 (50%), and 0.21 ± 0.06 (10%). Mean contrast sensitivity for a 3 mm pupil was 1.9 ± 0.2 for 10 cpd, 1.2 ± 0.15 for 20 cpd, and 0.9 ± 0.1 for 25 cpd. For a 5.5 mm pupil, contrast sensitivity was 1.4 ± 0.2 (10 cpd), 0.9 ± 0.2 (20 cpd), and 0.6 ± 0.2 (25 cpd). MTFs and PSFs were comparable in the two groups for both pupils. Conclusions: The higher-order aberrations seen in idiopathic amblyopic eyes alone do not appear to contribute to the decreased visual function. [Copyright &y& Elsevier]

Abstract: Purpose: To evaluate the power profile of multifocal contact lenses (CLs) using a new technology based on quantitative deflectometry. Methods: The Nimo TR1504 was used to analyze the power distribution of multifocal CLs. The CLs under study were: Air Optix Aqua Multifocal Low, Medium and High Addition and Focus Progressives. Three lenses of each model were considered. Results: All multifocal CLs showed a power profile characterized by a change toward more positive power values when aperture sizes become smaller. The near refractive addition of the lenses under study was +2.61D, +1.44D, +1.30D and +0.30D for the Focus Progressives, the Air Optix Aqua Multifocal High, Medium Add and Low Add, respectively. The refractive power of the Focus Progressives did not reach the value of the nominal distance power until a radial distance of 0.9mm from the center of the lens. For the Air Optix Aqua Multifocal Low Add the distance nominal power was reached at a radial distance of 1.5mm from the center of the lens, whereas this occurred at a distance of 1.8mm for the Air Optix Aqua Multifocal Medium and High Add. Conclusion: The relation between the pupil diameter of the patients and the power profile of these CLs has a crucial implication on the final distance correction and near addition that these lenses provide to patients. Practitioners should know the power profile of these CLs and measure the pupil diameter of each patient in different situations in order to carry out a customized fitting. [Copyright &y& Elsevier]

PURPOSE: To evaluate visual and optical quality of the implantable collamer lens for different powers and sizes of incision surgery. DESIGN: Prospective study in humans. METHODS: An adaptive optics visual simulator was used to measure 3 powers of implantable collamer lenses and simulate the implantable collamer lens wavefront aberration's pattern for small- and large-incision surgery. Visual acuity (VA) and contrast sensitivity were measured in 11 observers for 3- and 5-mm pupils. Modulation transfer function, point spread function, and Strehl ratio were calculated. RESULTS: At 3 mm pupil, no statistically significant differences were found between both incision sizes for any implantable collamer lens power, except for L15 diopter (D) implantable collamer lens at 25 cycles/degree (cpd) (P<.05). At 5 mm pupil, statistically significant differences in Strehl ratio, VA, and contrast sensitivity were found between both incision sizes for all implantable collamer lens powers (P < .05). The outcomes were better with small incision. Implantable collamer lens power also affected the optical and visual quality. At 3 mm pupil, no statistically significant differences were found in VA and contrast sensitivity between implantable collamer lens powers, except between L3 and L15 D at low-contrast VA and at 20 and 25 cpd (P < .05). At 5 mm pupil, no statistically significant differences were found in Strehl ratio, VA, and contrast sensitivity between L3 and L6 D implantable collamer lens, but they did become apparent for L15 D implantable collamer lens for both incision sizes, all contrasts and spatial frequencies (P<.05). CONCLUSIONS: The implantable collamer lens provides good optical and visual quality, although these outcomes decreased with large-incision surgery because of the increase of aberrations. [ABSTRACT FROM AUTHOR]