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Purpose: To determine the reliability of swept- source optical coherence tomography in cases in which soft contact lenses cannot be removed when acquiring biometric measurements., Methods: Eight subjects were included and only one eye per participant was analyzed. Each eye was measured six times by swept-source optical coherence tomography with the IOLMaster 700 instrument (Carl Zeiss Meditec, Jena, Germany). Axial length, central corneal thickness, anterior chamber depth, lens thickness, and keratometric measurements were evaluated for the naked eye and while wearing soft contact lenses of three different powers (-1.5, -3.0, and +2.0 D)., Results: There were statistically significant changes in axial length, central corneal thickness, anterior chamber depth, and keratometric measurements with soft contact lenses as compared to the naked eye (p<0.001). However, there were no significant differences in lens thickness outcomes between the naked eye and while wearing the three soft contact lenses (p>0.5). The changes in axial length, central corneal thickness, and anterior chamber depth were lens-specific and dependent on the thickness of the lens used., Conclusions: Sept-source optical coherence tomography based lens thickness measurements while wearing soft contact lenses are comparable to those of the naked eye. However, the thickness and the optical design of the soft contact lens may lead to significant differences in the axial lengh, central corneal thickness, anterior chamber deph, and keratometric measurements.

Background: The aim was to assess the optical quality of four Boston contact lens materials with an optical device based on Schlieren interferometry., Methods: The NIMO TR1504 (Lambda-X, Nivelles, Belgium) was used to measure higher-order aberrations and their corresponding root mean square values of four different rigid gas permeable contact lenses made from four different Boston materials: EO, ES, XO and XO2 . For each lens, 30 measurements were performed with two optical apertures: 3.0 mm and 6.0 mm. The modulation transfer function, point spread function, Strehl ratio and a simulation of the image provided by the lens were computed from the Zernike coefficients measured up to the fourth order., Results: The root mean square error of higher-order aberrations varied significantly with material type for both optical apertures (p < 0.01). The largest difference was obtained between the Boston EO and the Boston ES materials (for a 6.0 mm aperture), the mean difference being (8.3 ± 0.2) × 10(-2) µm. The modulation transfer functions, point spread functions and Strehl ratio values were similar among all Boston materials at the smaller optical aperture; however, differences between each material were more apparent for the 6.0 mm aperture, with the Boston ES material exhibiting the best optical quality., Conclusions: In terms of all metrics analysed, all Boston materials examined showed comparable optical quality for a 3.0 mm aperture but the Boston ES material displayed the best optical quality for a 6.0 mm optical aperture., (© 2016 Optometry Australia.)

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 -3D 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 0.04D to 0.12D), 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 0.12D for the multifocal contact lenses., (Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Objective: To assess and compare the effects of four simultaneous-image multifocal contact lenses (SIMCLs), and those with distant-vision-only contact lenses on visual performance in early presbyopes, under dim conditions, including the effects of induced glare., Methods: In this double-masked crossover study design, 28 presbyopic subjects aged 40 to 46 years were included. All participants were fitted with the four different SIMCLs (Air Optix Aqua Multifocal [AOAM; Alcon], PureVision Multifocal [PM; Bausch & Lomb], Acuvue Oasys for Presbyopia [AOP; Johnson & Johnson Vision], and Biofinity Multifocal [BM; CooperVision]) and with monofocal contact lenses (Air Optix Aqua, Alcon). After 1 month of daily contact lens wearing, each subject's binocular distance visual acuity (BDVA) and binocular distance contrast sensitivity (BDCS) were measured using the Functional Visual Analyzer (Stereo Optical Co., Inc.) under mesopic conditions (3 candela [cd]/m) both with no glare and under the 2 levels of induced glare: 1.0 lux (glare 1) and 28 lux (glare 2)., Results: Among the SIMCLs, in terms of BDVA, AOAM and PM outperformed BM and AOP. All contact lenses performed better at level without glare, followed by Glare 1, and with the worst results obtained under glare 2. Binocular distance contrast sensitivity revealed statistically significant differences for 12 cycles per degree (cpd). Among the SIMCLs, post hoc multiple comparison testing revealed that AOAM and PM provided the best BDCS at the three luminance levels. In both cases, BDVA and BDCS at 12 cpd, monofocal contact lenses outperformed all SIMCL ones at all lighting conditions., Conclusions: Air Optix Aqua Multifocal and PM provided better visual performance than BM and AOP for distance vision with low addition and under dim conditions, but they all provide worse performance than monofocal contact lenses.

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 +2.61 D, +1.44 D, +1.30 D and +0.30 D 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 0.9 mm 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 © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To evaluate the effects of a central hole contact lens-based design on visual performance and to compare it with the standard version of that same contact lens without the hole (non-hole scenario)., Methods: The visual performance of 10 myopic patients wearing either a central hole myopic contact lens or its corresponding standard version (non-hole contact lens) was assessed on the same eye. Monocular corrected distance visual acuity was measured under photopic conditions and monocular contrast sensitivity was measured under both photopic and mesopic conditions and higher-order ocular aberrations using Hartmann-Shack aberrometry. An in vitro optical analysis of both contact lenses was performed and a symptoms questionnaire was administered to the participants., Results: No statistically significant differences in terms of corrected distance visual acuity were found: -0.091 and -0.098 logMAR for the hole and non-hole contact lenses, respectively (P > .05). Contrast sensitivity was comparable between lenses and no differences were found for specific spatial frequencies or a particular luminance level (P > .05). The hole contact lenses provided excellent outcomes, essentially equivalent to those of non-hole contact lenses, even in terms of subjective symptoms such as glare or halo. In vivo and in vitro optical quality analysis revealed no statistically significant differences between the hole and the non-hole contact lenses for either pupil size (P > .1)., Conclusion: A contact lens having a central hole provides good visual and optical quality outcomes comparable to those yielded by the same lens without a hole. The results suggest that the impact of a central hole may be clinically negligible., (Copyright 2013, SLACK Incorporated.)

Purpose: To evaluate and compare the distribution of refractive power within the optic zone of different soft contact lenses and to investigate the effect of lens decentration on the power profiles., Methods: The Nimo TR1504 instrument was used to measure the optical power across different aperture diameters (from 1.5mm to 5.5mm in steps of 0.5mm) of four daily disposable contact lenses: DAILIES TOTAL1, Proclear 1-Day, SofLens daily disposable and 1-DAY ACUVUE MOIST. Measurements were performed using a wet cell. Power data were evaluated when contact lenses were in its centered position and after inducing different amounts of lens decentration (from 0.2mm to 1.0mm in steps of 0.2mm)., Results: All contact lenses showed an increase - more negative - in lens power with distance from the lens center. The amount of change varied depending on the lens. It was about 10% of lens power for DAILIES TOTAL1 (-0.29diopters (D)), SofLens daily disposable (-0.36D), and Proclear 1-Day (-0.32D) whereas 1-DAY ACUVUE MOIST showed a percentage variation of 3.3% (-0.10D). After inducing a lens decentration up to 1mm, the power curves were shifted in the negative direction. However, the change obtained in lens power compared with well-centered position was always lower than a quarter of diopter both for all the lenses and aperture diameters., Conclusions: Our results showed a variation of the refractive power from the lens center, becoming more negative toward the periphery, with a negligible effect of the decentration for all disposable contact lenses studied., (Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To evaluate and compare the visual performance of two simultaneous vision multifocal contact lenses (CLs)., Methods: In this cross-over study design 20 presbyopic subjects were fitted with two different simultaneous vision multifocal CLs (the PureVision Multifocal Low Add and Acuvue Oasys for Presbyopia) in random order. After 1 month, binocular distance visual acuity (BDVA) under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) conditions, binocular near visual acuity (BNVA), binocular distance contrast sensitivity function (CSF) under photopic and mesopic conditions, binocular near CSF and defocus curve were measured. Subjects were then refitted with the alternative correction and the procedure was repeated., Results: Mean BDVA under photopic conditions was similar for the Acuvue Oasys for Presbyopia and PureVision Multifocal Low Add: 0.01 ± 0.08 and 0.00 ± 0.08 logMAR, respectively (P = 0.45). Under mesopic conditions the values of BDVA were 0.20 ± 0.58 and 0.11 ± 0.09 logMAR, respectively (P = 0.005). Mean BNVA was 0.20 ± 0.05 and 0.15 ± 0.08 logMAR for the Acuvue Oasys and PureVision Low Add, respectively (P = 0.06). Binocular distance CSF testing revealed no statistically significant differences between lenses under photopic, mesopic or near conditions. Both lenses provided a comparable intermediate visual acuity., Conclusions: Both simultaneous vision multifocal CLs provided adequate distance visual quality under photopic and mesopic conditions, and better visual acuity was provided under mesopic conditions for the Purevision lens. Both lenses provided adequate visual performance at intermediate distance, but the near visual acuity appears to be insufficient for early presbyopes who require a moderately demanding near visual quality., (Ophthalmic & Physiological Optics © 2012 The College of Optometrists.)

Background: The aim was to evaluate the visual performance provided with a contact lens-based pinhole design against a simultaneous vision multifocal contact lens., Methods: In a cross-over study at the University of Valencia, 22 presbyopic patients were evaluated using an artificial pupil fitted on the non-dominant eye and the simultaneous vision PureVision Multifocal contact lenses. After one month of contact lens wear, binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance contrast sensitivity, binocular near contrast sensitivity, and stereoacuity were measured, under photopic conditions (85 cd/m(2)). In addition, binocular distance visual acuity and binocular distance contrast sensitivity were examined under mesopic conditions (5 cd/m(2))., Results: Mean binocular distance visual acuity for pinhole and PureVision Multifocal were 0.02 ± 0.04 and 0.01 ± 0.04 logMAR under photopic conditions and 0.16 ± 0.06 and 0.12 ± 0.04 logMAR for binocular near visual acuity under mesopic conditions, respectively. No statistically significant differences were found between both types of lenses at distance for both lighting levels and intermediate distances (p > 0.05). There was a significant difference at near vision under photopic conditions (p = 0.03). Binocular distance contrast sensitivity revealed statistically significant differences between the pinhole system and PureVision Multifocal for six and 12 cpd (cycles per degree) spatial frequencies at the two luminance levels, while for near vision, differences were also significant for 18 cpd. Stereoacuity was better with PureVision Multifocal (127 ± 49.3 seconds of arc) compared with the pinhole lens (220.2 ± 32.3 seconds of arc, p = 0.004)., Conclusion: Pinhole and PureVision Multifocal contact lenses provide good binocular vision for distance and functional intermediate vision. Although it was better with the PureVision Multifocal, near vision was not satisfactory for either of the two contact lens options., (© 2012 The Authors. Clinical and Experimental Optometry © 2012 Optometrists Association Australia.)

Objective: The aim of this study was to evaluate ocular aberration changes through different simultaneous vision multifocal contact lenses (CLs)., Methods: Eighteen young-adult subjects with a mean age of 29.8±2.11 years took part. Changes in accommodative response, spherical aberration (C(4)(0)), horizontal coma (C(3)(1)), vertical coma (C(3)(-1)), and root mean square (RMS) of higher-order aberrations (HOAs, third to sixth orders) were evaluated. Measurements were obtained with a distance-single vision CL and 2 aspheric multifocal CLs of simultaneous focus center-near design (PureVision Low Add and PureVision High Add) for 2 accommodative stimuli (-2.50 and -4.00 D). All measurements were performed monocularly with a Hartmann-Shack aberrometer (IRX-3; Imagine Eyes, Orsay, France)., Results: No statistically significant differences were found in accommodative responses to -2.50- and -4.00-D stimuli between the single vision CL and the 2 multifocal CLs. Spherical aberration was found to decrease and become more negative with accommodation for both stimuli with all three CLs. Horizontal coma decreased significantly with accommodation (-2.5- and -4.00-D stimuli) for the distance-single vision CLs (P=0.002 and P=0.003). No differences were found in vertical coma Zernike coefficients. The RMS of HOAs was found to decrease only with the single vision CLs for both stimuli (P<0.01)., Conclusions: Data obtained in this study suggest that in young subjects, the multifocal CLs studied do not induce large changes in accommodative response compared with the distance-single vision CLs. Spherical aberration reduced significantly with accommodation.

Purpose: To assess and compare the effects of contact-lens based artificial pupil design and monovision correction on visual performance., Methods: In a cross-over study design, 22 presbyopic patients (age range 50 to 64 years) were evaluated using artificial pupil contact lens on the non-dominant eye and monovision. After 1 month, binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance contrast sensitivity, binocular near contrast sensitivity, and stereoacuity were measured, under photopic conditions (85 cd/m2), in each patient after contact lens fitting. Moreover, BDVA and binocular distance contrast sensitivity were examined under mesopic conditions (5 cd/m2)., Results: Average artificial pupil contact lens and monovision BDVA were 0.02 ± 0.04 and 0.00 ± 0.09 logMAR for photopic conditions, and 0.16 ± 0.06 and 0.13 ± 0.12 logMAR for binocular near visual acuity under mesopic conditions, respectively. No statistically significant differences were found between the two types of lenses at distance for both lighting levels (p > 0.05), but there were, however, significant differences at intermediate distances and near vision (p < 0.05). Binocular distance contrast sensitivity revealed statistically significant differences between artificial pupil contact lens and monovision for 1.5 cycles per degree (cpd) under photopic conditions, and 12 and 18 cpd under mesopic conditions (p < 0.05), respectively. Statistically significant differences for all spatial frequencies except for 1.5 cpd were found at near vision (p < 0.05). The mean values of stereoacuity obtained for artificial pupil contact lens (221 ± 32 sec arc) were slightly worse than for monovision correction (210 ± 49 sec arc), and statistically significant differences were not found (p = 0.23)., Conclusions: Monovision performed better than an artificial pupil contact lens of the same material for near visual acuity and near contrast sensitivity. Only, the artificial pupil contact lens provides better intermediate visual acuity.

Purpose: To apply a commercially available high-resolution spectral domain optical coherence tomographer (SOCT) to assess the change in tear volume after application of a new artificial tears formulation specifically developed for contact lens (CL) users., Methods: Twenty OD from young healthy CL wearers (mean age, 24.7 ± 3.5 years) with refractive errors ranging from -0.75 to -2.50 D (mean, -1.56 ± 0.69 D) were examined. All subjects were fitted with Focus Dailies CL (Ciba Vision), and two drops of Blink Contacts (AMO), lubricating formulation specifically developed for CL wearers, were instilled after baseline measures. Tear meniscus volume (TMV) was measured immediately after and 1 min, 10, 30, and 60 min after instillation using the Copernicus HR SOCT (Optopol Tech., SA, Poland). TMV was calculated from the local area from tomograms assuming a regular distribution of the tear meniscus across the eyelid. Three scans were taken at each of the time points., Results: Mean meniscus volume without CL was 1.35 ± 1.18 μL, volume with CL was higher, 1.71 ± 1.56 μL but not significantly different (mean difference, 0.36 ± 1.31 μL). After instillation of Blink Contacts eye drops, meniscus volume increased to an average of 4.10 ± 2.91 μL. Repeated measures analysis of variance showed that values after 10 min were significantly higher than before instillation of eye drops (p < 0.01; mean difference, 0.77 ± 0.65 μL). After 30 and 60 minutes, values of TMV decreased to almost baseline (average mean difference from baseline 0.19 ± 0.18 μL at t30, p < 0.001, and 0.06 ± 0.08 μL at t60, p = 0.004)., Conclusions: High-resolution imaging of the lower tear film meniscus with SOCT systems provides useful measures of tear volume. An artificial tear formulation provides a change in tear volume that is maintained beyond 10 min, although further study, using control groups, would be desirable to determine the consistency of those higher-than-baseline values observed over time.

Purpose: To evaluate induced changes in pupil and accommodative response for different accommodative stimuli with three different multifocal contact lenses (CLs)., Methods: Accommodative and pupil responses with three aspheric multifocal CLs of simultaneous focus center near (PureVision Low Add, PureVision High Add and Focus Progressives) for two accommodative stimuli of -2.5 and -4.00 D were recorded in 10 young subjects. Accommodative response, peak velocity, and time constant of accommodation and pupil constriction were assessed. The measurements were evaluated in all the participants with distance-single vision CLs and with the three multifocal CLs. The monocular measurements were performed in a random sequence for each participant. All parameters were measured with a Hartmann-Shack aberrometer (IRX-3; Imagine Eyes, Orsay, France)., Results: Differences were not found in accommodation response for both accommodative stimuli studied between the single vision lens and the three different multifocal CLs (p > 0.05 for both stimuli). For the 2.5 D stimulus, significant differences were not found in peak velocity and time constant between the single vision lens and the three different multifocal CLs (p > 0.05 for all situations); in amplitude of pupil constriction, differences were only found for the situation with PureVision High Add, where the value was lower than the single vision lens (p = 0.015). For the 4.00 D stimulus, differences with single vision lens in peak of velocity and time constant were only found with PureVision Low Add, where the peak velocity value was higher and the time constant was lower (p = 0.024 and p = 0.032 for peak of velocity and time constant, respectively); for amplitude of pupil constriction differences were not found (p > 0.05)., Conclusions: Data obtained in this pilot study suggest that in young observers, the multifocal CLs studied do not induce large changes in accommodative system compared with the single vision lens.

Purpose: To evaluate accommodative response and facility in presbyopic patients fitted with several types of simultaneous-image multifocal contact lenses (CLs)., Methods: Six presbyopic patients, unadapted wearers of simultaneous-image bifocals, were fitted with the Focus Progressives and the low- and high-addition Pure Vision simultaneous vision multifocal CLs. Each individual wore each of the three types of lenses in successive random order. Accommodative response, accommodative facility, visual acuity, and contrast sensitivity at distance and near were evaluated in all cases. A control group of eight non-presbyopic patients was also studied., Results: The mean age was 28.6 ± 2.72 and 51.2 ± 5.81 years in the non-presbyopes and presbyopic patients, respectively. For the presbyopic group, statistically significant differences were not found for distance visual acuity between the baseline situations and with the three different CLs types. For the near visual acuity, there were no statistically significant differences between baseline situation (without add) compared with patients wearing the Focus Progressives and with PureVision Low Add. With the Purevision High Add, the near visual acuity was slightly better than baseline situation (p = 0.03). Non-presbyopic subjects showed relatively linear 1:1 stimulus response functions for all situations. Presbyopic subjects showed an increasing lag of accommodation with amplitude as they approach to the maximum amplitude for all situations. Distance and near accommodative facility rate for the presbyopic patients was zero for all conditions., Conclusions: The results of this study suggest that simultaneous-image multifocal CLs studied do not alter accommodative functions. The high add of the Purevision CL enhances near vision for advanced presbyopes compared with the other models studied.

Purpose: To evaluate the long-term predictability, stability, safety, and efficacy of the V4c Visian implantable collamer lens (ICL) with central hole to correct myopia.Patients and methods: One hundred and eighty-four eyes of 92 patients were evaluated during 3 years after implantation of the V4c ICL. The refraction, uncorrected distance visual acuity, best-corrected distance visual acuity, IOP, endothelial cell count, vault, and adverse effects were evaluated every 12 months during the whole follow-up.Results: The mean spherical equivalent dropped from -8.30±2.98 D preoperatively to -0.37±0.47 D at 36 months post-surgery, with 91.8% eyes being within ±1.00 D of emmetropia. With respect to the astigmatic components J0 and J45, 98.4% and 99.5% of eyes, respectively, were within ±0.50 D of the desired refraction. At 36 months, 78.8% of eyes had no change in the Snellen lines of best-corrected distance visual acuity, while 8.7% gained one line and 6.5% gained two or more lines; mean safety and efficacy indexes were 1.03 and 0.90, respectively. Mean endothelial cell count was 2,742±340 cells/mm2 before and 2,663±366 cells/mm2 at 36 months post-surgery. Mean IOP reduced from 13.7±1.9 mmHg preoperatively to 12.8±1.7 mmHg at 36 months post-surgery. Mean vault varied from 409±196 µm at 12 months to 349±165 µm at 36 months.Conclusion: The visual and refractive outcomes were very good and highly stable throughout the follow-up period, indicating that this ICL model may be predictable, stable, safe, and effective to correct myopia in the long term. [ABSTRACT FROM AUTHOR]

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Purpose To compare the visual quality of implantable collamer lens (ICL) with and without central hole (Hole ICL and conventional ICL) at different degrees of decentering. Methods An adaptive optics visual simulator (crx1, Imagine Eyes, Orsay, France) was used to simulate the -3, -6 and -12 dioptres (D) conventional and Hole ICLs in three conditions: centred and decentred 0.3 and 0.6 mm. Visual acuity (VA) at high-contrast, medium-contrast and low-contrast and contrast sensitivity (CS) were measured in 15 observers for 3 and 4.5 mm pupils. Results No statistically significant differences in VA and CS were found between conventional and Hole ICLs for any ICL powers and pupil sizes evaluated ( p>0.05). Regarding the effect of the ICL decentration on visual performance, we did not find statistically significant differences in VA and CS between centred, 0.3 and 0.6 mm decentred ( p>0.05). Moreover, the ICL decentration affected the same manner on the conventional and Hole ICLs. Conclusions The outcomes showed that conventional and Hole ICLs provided good and comparable visual performance for all powers and pupil sizes evaluated. Besides, ICL decentering affects the same manner both ICL models evaluated. The ICL decentering did not have any effect on the visual performance. [ABSTRACT FROM AUTHOR]

Purpose To quantify the optical quality of various daily disposable contact lenses in vivo and to ascertain its variation in terms of wearing time by means of objective non-invasive determination of wavefront patterns. Methods The crx1 adaptive-optics system was used to measure the wavefront aberrations in 15 myopic eyes before and at 2-h intervals after contact lens fitting, over a 12-h wearing period. Seven types of contact lenses having different material, water content and lens design were evaluated in this study: Dailies Total1, Dailies Aqua Comfort Plus, Proclear 1 Day, 1-Day Acuvue Tru Eye, 1-Day Acuvue moist, Sof Lens daily disposable and Clariti 1-Day. The aberration data were analysed by fitting Zernike polynomials up to the 5th-order for 3 and 5-mm pupils. The optical quality under each condition and at each point in time was described by means of the Root-Mean-Square ( RMS) value of wavefront aberration, Modulation Transfer Function ( MTF), Point Spread Function and cut-off spatial frequency. Results A RMS increase was observed after contact lens fitting as well as over time, both for a 3-mm and a 5-mm pupil. Each type of lens induced a different amount of wavefront aberrations, which vary over time also in a different manner. Dailies Total1 showed the lowest RMS values both at baseline and at the end of the day. In addition, Dailies Total1 provided the best MTF out of all the contact lenses that were assessed. These observations were reflected in higher cut-off spatial frequencies and visual resolution both at baseline and after 12 h of wearing time. Conclusions Aberrometry makes it possible to analyse accurately and in vivo the optical quality of contact lenses and to assess how lenses having different characteristics - such as material or water content - behave for different wearing times. These variations across contact lenses may result in differences in visual performance. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia 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.)

Purpose To assess the effect of seven different daily disposable contact lenses upon corneal thickness, as well as upon tear meniscus volume, by using optical coherence tomography (OCT). Methods Thirty-four young healthy subjects wore seven different types of daily disposable soft contact lenses, each for a period of 12 h: Delefilcon A, Nelfilcon A, Omafilcon A, Filcon II3, Narafilcon A, Etafilcon A and Hilafilcon B. Central and mid-peripheral corneal thickness and lower tear meniscus volume (TMV) were measured using an OCT device during contact-lens wear at 4-h intervals throughout a 12-h period. Measurements were also recorded without any contact lenses being worn during a day. Results In the no-lens scenario a small but significant ( p < 0.05) thinning in the cornea was observed after the 12-h period. Overall, as for contact-lens wear, it was the Hilafilcon B lens that caused the greatest thickness increase in the central area, whereas the Etafilcon A caused it in the mid-peripheral cornea. Delefilcon A was the lens that showed the most similar behavior to the naked eye. As for TMV, it decreased with all the lenses, but it was the Delefilcon A lens the one that caused the smallest drop in TMV ( p = 0.007). Conclusions OCT makes it possible to evaluate both corneal thickness variations and TMV changes as a result of contact-lens wear. The changes in corneal thickness hereafter presented are not clinically significant. On the other hand, TMV drop could indicate discomfort for contact-lens users. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of different contact lens–based artificial pupil designs on visual performance. Setting: University of Valencia, Burjassot, Spain, and University of Manchester, Manchester, United Kingdom. Design: Comparative case series. Methods: Presbyopic patients were evaluated using 4 artificial pupil designs in the nondominant eye. Binocular uncorrected distance visual acuity (UDVA), binocular corrected distance visual acuity (CDVA), binocular uncorrected near visual acuity (UNVA), binocular distance-corrected near visual acuity (DCNVA), defocus curve, binocular distance, and near contrast sensitivity under photopic and mesopic conditions, and stereoacuity were measured after contact lens fitting. Results: The mean UDVA and CDVA ranged from 0.04 ± 0.05 (SD) to −0.01 ± 0.04 logMAR and from −0.02 ± 0.05 to −0.05 ± 0.03 logMAR, respectively. The UNVA and DCNVA ranged from 0.37 ± 0.11 to 0.42 ± 0.20 logMAR and from 0.35 ± 0.17 to 0.38 ± 0.12 logMAR, respectively. The difference in binocular distance contrast sensitivity was statistically significant between the pinhole systems and the control group (distance-corrected patients without pinhole lens) for 6 cycles per degree (cpd), 12 cpd, and 18 cpd; for near vision, differences were also significant for 3 cpd at the 2 luminance levels (P<.05). Stereoacuity values for near vision were not significantly different between the 4 pinhole systems (P>.05). Conclusions: Soft contact lens apertures provide good visual acuity at distance, functional intermediate vision, and poor near visual acuity and stereoacuity. An improvement in visual performance with decreasing pupil diameter was not found. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [Copyright &y& Elsevier]

Purpose: To evaluate the efficacy, predictability, and safety of a phakic posterior chamber intraocular Collamer lens (ICL) after penetrating keratoplasty (PKP). Setting: Fernández-Vega Ophthalmological Institute, Oviedo, Spain. Methods: A myopic or toric ICL was implanted after PKP in eyes unable to wear glasses or contact lenses and for which corneal laser surgery was contraindicated. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, and endothelial cell count were recorded preoperatively and 24 months postoperatively. Results: Preoperatively, the 15 eyes had myopia from −2.00 to −17.00 diopters (D) or astigmatism from −1.50 to −7.00 D. Twenty-four months postoperatively, the mean Snellen decimal UDVA was 0.51 ± 0.30 (SD). The UDVA was 20/40 or better in 7 eyes (46.6%). The mean CDVA was 0.79 ± 0.22. The CDVA was 20/40 or better in 12 eyes (80%) and 20/25 in 6 eyes (40%). No eye lost more than 1 line of acuity, 2 eyes gained 1 line, and 5 eyes gained more than 2 lines; 8 eyes were unchanged. The safety index was 1.58. The spherical equivalent (SE) was within ±1.00 D in 80% of eyes and within ±0.50 D in 66.6% of eyes. The mean postoperative SE was −0.95 ± 1.12 D. At 24 months, the mean vault was 2.06 ± 0.96 and the mean endothelial cell loss, 8.1%. Conclusion: Results indicate that phakic intraocular lens implantation is a viable treatment for myopia and astigmatism after PKP in patients for whom glasses, contact lenses, or corneal refractive surgery are contraindicated. [Copyright &y& Elsevier]

Purpose: To investigate the effect of 3rd-order aberrations on human vision. Setting: Grupo de Ciencias de la Visión, University of Murcia, Murcia, Spain. Methods: The 3rd-order aberrations coma and trefoil were induced with purpose-designed soft contact lenses, 3 inducing coma (low [0.05 μm], medium [0.13 μm], high [1.03 μm]) and 3 inducing trefoil (low [0.07 μm], medium [0.17 μm], high [0.96 μm]). Monocular high-contrast (HCVA) and low-contrast (LCVA) visual acuities and contrast sensitivity were measured in 11 subjects wearing contact lenses with a 5.0 mm artificial pupil. Results: The reduction in HCVA and LCVA was statistically significant only for the highest coma and trefoil values (P<.0001). For coma, the mean change in HCVA was 0.193 logMAR ± 0.100 (SD) and in LCVA, 0.386 ± 0.136 logMAR. For trefoil, it was 0.204 ± 0.128 logMAR and 0.395 ± 0.141 logMAR, respectively. No differences were found for the lower degrees (P>.2). Contrast sensitivity was significantly reduced with the highest coma and trefoil values (P<.0001) (mean change 0.390 ± 0.157 and 0.404 ± 0.135, respectively). Lower degrees did not cause significant changes in contrast sensitivity (P>.1). The effect of induced coma and trefoil on HCVA, LCVA, and contrast sensitivity was similar at each level of induced aberration (P>.01). Conclusions: Large values of coma and trefoil (approximately 1 μm) significantly reduced visual performance. Only patients with high 3rd-order aberrations, such as those that occur in refractive surgery or in cases of distorted optics, would benefit from this correction. [Copyright &y& Elsevier]

Purpose: To evaluate the relationship between subjective measurements of vault and objective values measured with Visante optical coherence tomography (OCT) in eyes receiving an implantable contact lens (ICL) for myopia correction. Design: Observational cross-sectional study. Methods: setting: Fernández-Vega Ophthalmological Institute, Oviedo, Spain. patients: Four hundred and fifty-two eyes from 246 patients were elected to be implanted with a Visian ICL V4 (STAAR Surgical Inc, Monrovia, California, USA). observation procedures: Subjective and objective measurements of vault after implantation of ICL. main outcome measures: Subjective vault classified in 5 levels assessed using an optical section during slit-lamp examination. Objective vault was measured with Visante OCT (Carl Zeiss Meditec Inc, Dublin, California, USA). Results: Average values of objective and subjective vault were 414 ± 228 μm and 2.1 ± 1.0, respectively and both parameters were highly correlated (r = 0.82; P < .001). Differences in average objective vault were statistically significant among the 5 groups of subjective vault (P < .001). Subjective vault 0 corresponded to a mean OCT value of 62 ± 49 μm with 99% confidence interval (CI) [38; 86] μm; eyes with vault 1 to 203 ± 93 μm with 99% CI [176; 230] μm; eyes with vault 2 to 402 ± 131 μm with 99% CI [378; 425] μm; eyes with vault 3 to 594 ± 146 μm, 99% CI [554; 633] μm; and vault 4 to 794 ± 182 μm with 99% CI [713; 875] μm. Conclusions: Subjective and objective values of vault are highly correlated. In 99% of cases within the CI, objective values for eyes subjectively classified within a certain level vary within a narrow interval (±25 to 80 μm) around the mean value, and this interval is characteristic of each subjective level. [Copyright &y& Elsevier]