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Purpose To evaluate the precision of objective refraction measurements with six different autorefractors that have different designs and measurement principles and to compare the objective refraction values with the subjective refraction. Method Objective refraction of 55 participants was measured using six autorefractors with different designs. The instrument features mainly varied in terms of measurement principles, inbuilt fogging, open or closed view, and handheld or stationary designs. Two repeated measurements of objective refraction were performed with each autorefractor. The objective refractions from the six autorefractors were compared with the standard subjective refraction. The repeatability limit and Bland-Altman were used to describe the precision and accuracy of each autorefractor, respectively. The analysis was done using the spherical component of the refraction and the power-vector components, spherical equivalent (M), and cylindrical vectors. Results The repeatability of all autorefractors was within 1.00 and 0.35D for measuring the M and both cylindrical components, respectively. Inbuilt fogging was the common feature of the instruments that showed better repeatability. Compared to subjective refraction, the mean difference for sphere and M was below +0.50D, and it was close to zero for the cylindrical components. The instruments that had inbuilt fogging showed narrower limit of agreement. When combined with fogging, the open field refractors showed better precision and accuracy. Conclusions The inbuilt fogging is the most important feature followed by the open view in determining the precision and accuracy of the autorefractor values.

Purpose: The aim of this study was to evaluate the effect of four different filters on contrast sensitivity under photopic and mesopic conditions with and without glare.Methods: A forced choice algorithm in a Bayesian psychophysical procedure was utilized to evaluate the spatial luminance contrast sensitivity. Five different spatial frequencies were evaluated: 1.5, 3, 6, 12, and 18 cycles per degree (cpd). The measurements were performed under 4 settings: photopic and mesopic luminance with glare and no glare. Two long pass filters (LED light reduction and 511nm filter) and two selective absorption filters (ML41 and emerald filter) and a no filter condition were evaluated. The measurements were performed in 9 young subjects with healthy eyes.Results: For the no filter condition, there was no difference between glare and no glare settings for the photopic contrast sensitivity measurements whereas in the mesopic setting, glare reduced the contrast sensitivity significantly at all spatial frequencies. There was no statistically significant difference between contrast sensitivity measurements obtained with different filters under both photopic conditions and the mesopic glare condition. In the mesopic no glare condition, the contrast sensitivity at 6 cpd with 511, ML41 and emerald filters was significantly reduced compared to no filter condition (p = 0.045, 0.045, and 0.071, respectively). Similarly, with these filters the area under the contrast sensitivity function in the mesopic no glare condition was also reduced. A significant positive correlation was seen between the filter light transmission and the average AULCSF in the mesopic non-glare condition.Conclusion: The contrast sensitivity measured with the filters was not significantly different than the no filter condition in photopic glare and no glare setting as well as in mesopic glare setting. In mesopic setting with no glare, filters reduced contrast sensitivity.

To report visual and refractive results in radial keratotomy (RK) patients that underwent a cataract surgery with a monofocal intraocular lens (IOL) implantation with 1 year of follow-up. Twenty-eight eyes of 15 patients with cataract and the previous RK were included. All eyes underwent phacoemulsification and monofocal IOL implantation. IOL power calculation was done using the Double-K formula of Aramberri. The preoperative versus postoperative corrected distance visual acuity (CDVA) and the uncorrected distance visual acuity (UDVA) values were used to assess the efficacy and safety of the surgery; meanwhile, the achieved versus the expected refractive outcomes postoperatively were used to assess the predictability. Phacoemulsification and IOL implantation was performed successfully in all eyes, and no intra- and postoperative problems occurred. The mean logMAR UDVA significantly improved from 0.7 ± 0.3 to 0.4 ± 0.2 at 6 months, and 0.3 ± 0.2 at 12 months postoperatively. By the end of the follow-up period, about 60% of the eyes achieved 20/25 or better CDVA, 25% of the eyes gained three or more lines of visual acuity, and two eyes had lost one or more lines of visual acuity. The mean spherical equivalent improved from − 1 ± 6.00 to − 0.75 ± 1.1 D by the end of the follow-up, and about 60% of the eyes were within ± 1 D at 12 months after the surgery. No intra- and postoperative problems occurred. Pseudophakic monofocal IOL implantation offers good visual acuity recovery and acceptable refractive correction in RK patients after 1-year follow-up.

Purpose To compare changes in the ciliary muscle area at different sectors between pre-presbyopic and presbyopic eyes during accommodation by means of an anterior segment optical coherence tomographer (OCT). Methods The anterior ciliary muscle area was measured in 20 healthy and phakic pre-presbyopic eyes, whose mean age was 23.3 ± 4.4 years, and in 20 healthy and phakic presbyopic eyes, whose mean age was 46.5 ± 5.2 years. The relative change in the cross-sectional area of the ciliary muscle was measured at the nasal, inferior, and temporal sectors between 0 and −3 D of vergence, in −1 D step. A linear model was used to assess the correlation of each eye parameter with the accommodative demand. Results Each population group showed a significant increase in the anterior ciliary muscle area for each sector. The maximum increase in the ciliary muscle area within the pre-presbyopic group was about 30%, and for the presbyopic one was about 25%. At the same time, it was obtained that the larger the vergence, the larger the variability. Furthermore, the linear model showed a positive tendency between the change in the ciliary muscle area of each sector and the vergence for both population groups, which coefficient of determination was in all cases greater than 0.93. Conclusion The anterior ciliary muscle area tends to increase with accommodation. The presbyopic nasal, inferior, and temporal ciliary muscle seem to have the same contractile capability as the young presbyopic ciliary muscle. These results might help to increase the evidences in the knowledge regarding the modern understanding of accommodation biometry and biomechanics.

© 2020 The Author(s)., [Objectives]: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters., [Methods]: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs)., [Results]: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22–0.47; p < 0.001) for tocilizumab, 0.82 (0.71–1.30; p 0.82) for IHDC, 0.61 (0.43–0.86; p 0.006) for PDC, and 1.17 (0.86–1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02–0.17; p < 0.001)., [Conclusions]: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situation., IJ has received honoraria for participating in an advisory board from Gilead Sciences, and for educational activities from ViiV. JB has received research grants from AbbVie, Gilead Sciences, Merck, and ViiV, and honoraria for being a speaker or advisory board participation from AbbVie, Gilead Sciences, Janssen, Merck, and ViiV. JRA received fees for participating in an advisory board, being a speaker, and research grant support from Viiv, Janssen, Gilead, MSD, Teva, Alexa and Serono. PR is involved as speaker or advisory board participant for Gilead Sciences, AbbVie and ViiV. JR-B, JP, JC and MY have no conflicts of interest to declare. SAM-COVID was funded by Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III (COV20/01031) co-funded by European Union (ERDF/ESF, “Investing in your future”) and Fundación SEIMC/GeSIDA. In addition, Juan Berenguer, Jesús Rodríguez-Baño, Inmaculada Jarrín, Jordi Carratalá, Jerónimo Pachón, and José R Arribas received funding for research from Plan Nacional de I+D+i 2013-2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades – co- financed by European Development Regional Fund “A way to achieve Europe”, Operative program Intelligent Growth 2014–2020 through the networks: Spanish AIDS Research Network (RIS) [RD16/0025/0017 (JB), RD16/0025/0018 (JRA), RD16/0025/00XX (IJ)] and Spanish Network for Research in Infectious Diseases (REIPI)[RD16/0016/0001 (JRB), RD16/0016/0005 (JC), and RD16/0016/0009 (JP).

BACKGROUND To assess the repeatability and agreement between a new high-resolution optical coherence tomographer (OCT) and a Scheimpflug topographer. MATERIAL AND METHODS Sixty phakic and healthy participants were measured in this study, and one eye per participant was analyzed. Depending on their refractive error, each participant was allocated into a myopic, hyperopic, or emmetropic group. The Cirrus HD-OCT 5000 (Carl Zeiss Meditec, Jena, Germany), and the Sirius Scheimpflug topographer (Costruzione Strumenti Oftalmici, Florence, Italy) were used to take all measurements. RESULTS The repeatability of these instruments to measure the anterior chamber depth, angle-to-angle, thinnest pachymetry, and both nasal and temporal angles was smaller than 0.15 mm, 0.40 mm, 10 µm, and 10 degrees, respectively. However, the repeatability of the Scheimpflug instrument to measure the apex pachymetry was about 15 µm, and for the OCT, it was about 4 µm for all groups. On average, the Sirius Scheimpflug instrument measured shallower anterior chamber depth (about 0.10 mm), shorter angle-to-angle (about 0.5 mm), thinner corneas (approximately 10 µm), and narrower angles (around 5 degrees) for all refractive groups. CONCLUSIONS The repeatability of the Cirrus OCT and Sirius Scheimpflug instrument was good and independent of the refractive error. Nevertheless, to judge whether these instruments could be used interchangeable, clinical criteria are needed.

To assess the power profile and in vitro optical quality of scleral contact lenses with different powers as a function of the optical aperture. The mini and semiscleral contact lenses (Procornea) were measured for five powers per design. The NIMO TR-1504 (Lambda-X) was used to assess the power profile and Zernike coefficients of each contact lens. Ten measurements per lens were taken at 3- and 6-mm apertures. Furthermore, the optical quality of each lens was described in Zernike coefficients, modulation transfer function, and point spread function (PSF). A convolution of each lens PSF with an eye-chart image was also computed. The optical power fluctuated less than 0.5 diopters (D) along the optical zone of each lens. However, the optical power obtained for some lenses did not match with its corresponding nominal one, the maximum difference being 0.5 D. In optical quality, small differences were obtained among all lenses within the same design. Although significant differences were obtained among lenses (P

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.

BACKGROUND The power profile of multifocal contact lenses has been demonstrated to report important information that could be used during the fitting process. The aim of this work is to describe the power profile of a recent set of gas permeable multifocal contact lenses as a function of the pupil radius. METHODS The measured multifocal contact lenses have a centre-distance design, and are available with five distance-vision diameters (XS, S, M, L and XL) and two different additions: Type A (up to +2.00 D) and Type B (up to +2.50 D). The optical device NIMO TR1504 (Lambda-X, Nivelles, Belgium) was used to obtain the power profile measurements. The optical lens power distribution as a function of the aperture radius was described in terms of radial computed colour maps, radial averaged power profiles, addition, and lens portion used for near vision. RESULTS The amount of total addition achieved depends on the diameter of the distance-vision area. That is, the bigger the distance vision area, the bigger the radius of the lens in order to get the same level of addition. In other words, the XS lens provides higher addition values compared to the XL lens design for a given aperture. CONCLUSIONS The XS and S designs seem to be aimed to favour near vision, whereas the L and XL designs seem to favour distance vision. For this reason, patients who demand good distance vision might benefit from the L or XL designs, and those with high demand on near-vision tasks might benefit from the XS or S designs. The M design could be the best option for those patients who have the same needs for distance and near vision.

The aim of this pilot study was to evaluate a new semiautomatic procedure to assess in vivo changes in the crystalline lens and ciliary muscle during accommodation. A total of 14 subjects were divided into two groups, young (aged between 20 and 25 years) and adult (aged between 35 and 40 years), and measured with an anterior segment optical coherence tomography. A semiautomatic procedure was implemented to measure the central lens thickness (CLT), anterior lens radius (ALR) and the ciliary muscle area (CMA) for the unaccommodated eye and for a vergence of − 3.00 D. The CLT increase for each population group was smaller than 5%, and the dispersion of each group was similar between them. Contrariwise, the reduction in the ALR was about 30% for both groups, although the young one showed the largest variability. The CMA increase was smaller than 30% for both groups, and the dispersion was similar between them. For each metric, differences between both groups were not statistically significant. The semiautomatic procedure seems to be useful for the in vivo analysis of the accommodative system. Additionally, the results obtained showed that changes in the CLT were much smaller compared to those obtained for the ALR or CMA.

The purpose of the study was to assess non-invasively the changes in the anterior chamber eye, crystalline lens morphology, and ciliary muscle during accommodation by means of an anterior chamber optical coherence tomographer (OCT), and correlate them with vergence. Twenty-five eyes of twenty-five healthy subjects, whose mean age was 29.9±7.1 years, were included and measured with an anterior chamber OCT. The central corneal thickness (CCT), anterior chamber depth (ACD), anterior crystalline lens radius of curvature (ALRC), crystalline lens thickness (CLT), and ciliary muscle area (CMA) were measured for each participant at 0, –1, –2, and –3 D of target vergence. A linear model was used to assess the correlation of each eye parameter with the vergence demand. The mean CCT showed no change for all the accommodative stimuli. The mean ACD and ALRC decreased with the vergence, about 4.5 and 30 % at –3 D, respectively. On the contrary, the CLT and CMA showed an opposite tendency, where the mean CLT was increased by 4.0 % and the mean CMA was done by 26% at –3 D. Statistical significant differences (p < 0.001) were obtained among all vergences for each eye metric, except for the CCT (p = 0.76). The ACD and ALRC decreased about 2 and 10 % per dioptre of accommodation, respectively; whereas the CLT and CMA increased about 2 and 9 %, respectively. These results add knowledge regarding the understanding of accommodation and give new perspectives for biomechanics and biometry.

The aim of this review is to summarize the results of using posterior chamber phakic intraocular lenses (pIOLs) to restore quality of vision in keratoconus patients. These pIOLs can correct the refractive errors associated with keratoconus and can also be combined with other surgical techniques to improve the results.

To analyze the effect of decentration on the optical quality of two diffractive-refractive intraocular lenses, a bifocal and a trifocal, when displaced laterally (horizontal direction) from the center.The AT LISA 809M IOL (+3.75 D add) with two main foci and the AT LISA tri 839MP intraocular lens with three main foci (Carl Zeiss Meditec AG, Jena, Germany) were analyzed. The optical quality of the intraocular lenses was measured with the PMTF (power and modulation transfer function [MTF] measurement for refractive and diffractive intraocular lenses) optical bench (Lambda-X, Nivelles, Belgium). The optical quality of the lenses was evaluated by the MTF at different object vergences, the average modulation in the range of frequencies from 0 to 100 cycles/mm, and the through-focus MTF curves. All measures were recorded when the intraocular lenses were centered and decentered for 3.0- and 4.5-mm apertures. The Strehl ratio and the percentage of energy allocated at each focus at the centered position were also obtained.Our results showed a lower optical quality with increasing decentration. The MTFs for the diffractive-refractive intraocular lenses decreased when the intraocular lenses were decentered. Also, the relative percentages of light energy allocated at each object vergence, for both intraocular lenses, agreed well with theoretical specifications and were consistent with the overall design of each lens.The optical quality of these diffractive-refractive multifocal intraocular lenses was slightly reduced when the induced decentration was less than 0.4 mm. For a decentration of 0.4 mm, the maximum difference in average modulation values was about 18% compared to the centered position.

Purpose: To measure changes in the anterior ciliary muscle during accommodation at the nasal, superior, temporal, and inferior sectors by means of an anterior chamber optical coherence tomographer, and correlate them with vergence changes. Methods: Twenty-four subjects with healthy, phakic eyes, whose mean age was 27.1 ± 8.9 years, underwent measurement with an anterior chamber optical coherence tomographer. The anterior ciliary muscle was measured at the nasal, temporal, superior, and inferior sectors for 0, -1, -2, and -3 D of vergence. A linear model was used to assess the correlation of each eye parameter with the accommodative demand. Results: The anterior ciliary muscle area significantly increased with accommodation for each sector, with a maximum increase of about 30% for the nasal-temporal sectors and about 25% for the inferior-temporal sectors. The linear model showed a tendency toward a positive relationship between change in the ciliary muscle area of each sector and vergence. Conclusion: The anterior ciliary muscle area tends to increase with accommodation, although the increase has been shown to be symmetric between the pair sectors superior-nasal and inferior-temporal. These results may help to increase understanding of accommodation biometry and biomechanics. RESUMO Objetivo: Medir as alterações do músculo ciliar anterior durante a acomodação nos setores nasal, superior, temporal e inferior, através de um tomógrafo de coerência óptica de câmara anterior, e correlacioná-las com alterações de vergência. Métodos: Vinte e quatro indivíduos com olhos saudáveis e fácicos, com idade média de 27,1 ± 8,9 anos, foram submetidos à medida com um tomógrafo de coerência óptica de câmara anterior. O músculo ciliar anterior foi medido nos setores nasal, temporal, superior e inferior para 0, -1, -2 e -3D de vergência. Um modelo linear foi utilizado para avaliar a correlação de cada parâmetro do olho com a demanda acomodativa. Resultados: A área do músculo ciliar anterior aumentou significativamente com a acomodação em cada setor, com um aumento máximo foi de cerca de 30% para os setores naso-temporais, e cerca de 25% para os inferiores-temporais. O modelo linear mostrou uma tendência para uma relação positiva entre a alteração da área do músculo ciliar de cada setor e a vergência. Conclusão: A área do músculo ciliar anterior tende a aumentar com a acomodação, embora o aumento tenha se mostrado simétrico entre os setores superior-nasal e inferior-temporal. Estes resultados podem ajudar a aumentar a compreensão da biometria e biomecânica da acomodação.

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 (p0.5). 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.

The purpose was to evaluate the repeatability of a new swept-source optical biometer for measuring ocular biometric parameters. Thirty subjects with healthy and phakic eyes were included in this study, and only one eye per participant was analysed. Each eye was measured five times with the IOLMaster 700 swept-source optical biometer (Carl Zeiss Meditec, Jena, Germany). Axial length (AL), anterior chamber depth (ACD), central corneal thickness (CCT), lens thickness (LT), white-to-white (WTW), and K1 and K2 keratometric readings were evaluated. The repeatability of swept-source biometry was evaluated on the basis of five measurements captured for each patient. The repeatability limits for the axial measurements AL, ACD, CCT, and LT were 0.03, 0.07, 0.004, and 0.11 mm, respectively. For the WTW distance and both keratometry readings, the repeatability limits were 0.20, 0.06, and 0.05 mm, respectively. The AL resulted in the lowest coefficient of variation, and the LT had the highest one. The spherical equivalent showed statistically significant negative correlations with the AL and ACD. Swept-source optical biometry showed high repeatability performance for all biometric parameters in healthy eyes, where the correlation between the spherical equivalent and AL showed the strongest value.

To compare the optical quality between two intraocular lenses (IOLs): the Mini WELL Ready progressive multifocal (SIFI Medtech, Catania, Italy), and the TECNIS Symfony (Abbott Laboratories, Illinois, USA), which both provide a continuous range of vision from far to near positions. The in vitro optical quality of each lens was assessed with an instrument conceived for measuring the modulation transfer function (MTF). The optical quality of each lens was described in terms of MTF, through-focus MTF, defocus tolerance, pupil dependence, and Strehl ratio MTF. These metrics were assessed for the best lens far focus, and at four vergences (from −1.5 to −3.0 D in 0.5-D steps), at 3.0 and 4.5 mm apertures. The through-focus curves of each lens showed two main areas: one corresponding to far-distance vision, and another to intermediate- and near-distance vision. Both lenses showed similar MTF curves and Strehl ratio values at both apertures. The optical quality of both lenses slightly decreased with the aperture for all vergences. Nevertheless, the quality of the progressive multifocal lens increased with the aperture at far-distance vision. This lens also showed the largest defocus tolerance at near-distance vision for both apertures. The results obtained in the present study suggest that both designs might enlarge the depth of focus. Whereas, the Mini WELL Ready showed better optical quality than the TECNIS Symfony at far vision with 4.5 mm aperture, and larger defocus tolerance than the diffractive lens at near-distance vision.

Aim To evaluate the repeatability of an optical device for measuring the Zernike coefficients of toric intraocular lenses (IOLs) and assess whether its toricity has any impact in its repeatability. Methods An experienced technician used the NIMO TR1504 to measure the Zernike coefficients 30 times for an aperture of 4.50 mm for all lenses included. The IOLs included were divided into two group: toric and non-toric ones. The cylindrical powers of the toric lenses included in the present study were 1.00, 1.50, 2.25, 3.00 and 3.75 D. Finally, the repeatability of the NIMO TR1504 was described in terms of within subject standard deviation (Sw) and repeatability limit. Results The Sw was smaller than 0.011 µm for both lens groups and all Zernike coefficients, and the difference between both groups was smaller than 0.004 µm for all Zernike coefficients. Regarding the repeatability limit, this value was smaller than 0.025 µm for the toric lens group, and smaller than 0.031 µm for the non-toric lens one for all Zernike coefficients. Furthermore, the maximum difference between both lens groups was 0.010 µm. Conclusion The repeatability of the NIMO TR1504 to measure the optical quality is high and independent of the lens toricity. These results reflect that this system is robust and could be used to measure the in-vitro optical quality of either toric or non-toric IOLs.

PURPOSE: To compare the optical quality under large apertures among three multifocal intraocular lenses (IOLs): the TECNIS Symfony ZXR00 (Abbott Laboratories, Abbott Park, IL), the AT LISA tri 839MP (Carl Zeiss Meditec, Jena, Germany), and the Finevision (PhysIOL, Liège, Belgium). METHODS: The in vitro optical quality of each lens was assessed with an instrument that measured the modulation transfer function (MTF). The optical quality of each lens was described in terms of MTF and through focus average MTF. The Strehl ratio, cut-off frequency, area of visibility, and percentage energy were calculated to objectively describe the optical quality of each lens. These metrics were assessed for the best lens distance focus and at four vergences (from −1.50 to −3.00 D in 0.50-D steps) at a 4.5-mm aperture. RESULTS: The through focus average MTF of the AT LISA and Finevision IOLs showed three mean areas corresponding to distance, intermediate, and near vision. The TECNIS Symfony IOL showed two main areas corresponding to distance and intermediate vision. All metrics revealed that the Finevision IOL showed the best optical quality at distance vision, the TECNIS Symfony IOL at intermediate vision, and the AT LISA IOL at near vision. The TECNIS Symfony IOL showed the most homogeneous light distribution between its best vision foci. CONCLUSIONS: The TECNIS Symfony IOL is less vergence dependent than the AT LISA and Finevision IOLs under dim conditions. These results may help clinicians to choose the proper lens depending on the patient’s visual requirements. [ J Refract Surg. 2015;31(10):666–672.]

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.

Purpose To compare the optical quality in vitro of 2 designs of the Visian Implantable Collamer Lens phakic intraocular lens (pIOL) for different powers and optical apertures. Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods The Nimo TR1504 deflectometry device was used to measure the V4c pIOL, which has a smaller optic diameter, and the V5 pIOL, which has a larger optic diameter. The pIOLs were measured for −3.00 diopters (D), −6.00 D, −9.50 D, and −10.50 D at different optical apertures from 3.00 to 6.00 mm depending on the IOL power and model. The root mean square of higher-order aberrations (RMS HOAs) was analyzed. The Strehl ratio, point-spread functions (PSFs), and simulated images were calculated from wavefront aberrations. Results There were no statistically significant differences in any Zernike RMS or RMS HOAs between the 2 pIOL models with the same power and optical aperture (P > .05). Both pIOLs had negative spherical aberration that increased with the pIOL power. Strehl ratio values showed no statistically significant differences between the pIOLs with the same power and pupil aperture. Minimal differences were seen in the PSFs and simulated images between the pIOLs. Conclusions Both pIOLs showed good and comparable in vitro optical quality similar that of a perfect lens in that they should not affect visual performance after implantation. Patients with larger pupil diameters could benefit from the pIOL with the larger optic diameter because it showed better in vitro optical quality than the previous design with a smaller optic diameter. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Purpose To assess whether corneal parameters and aberrations are affected by accommodation. Setting Optics Department, University of Valencia, Valencia, Spain. Design Prospective cross-sectional study. Methods The Galilei G4 dual Scheimpflug device was used to obtain data on the anterior and posterior axial curvatures, total corneal power (TCP), and corneal pachymetry from 3 corneal zones (central: 0.0 up to 4.0 mm; paracentral or mid: 4.0 up to 7.0 mm; peripheral: 7.0 up to 10.0 mm) in young emmetropic eyes in the unaccommodated and 4 accommodated states (from −1.0 to −4.0 diopters [D] in 1.0 D steps). The 2nd-, 3rd-, and 4th-order aberrations as well as the root mean square (RMS) were also determined for the entire cornea at the same accommodative demands. Results The study evaluated 7 subjects (12 eyes). No significant changes in any measured parameter were found during accommodation for any corneal zone ( P > .05). Statistically significant differences were found in the various corneal zones when it was assumed they were constant with accommodation ( P Conclusion Different parameters in various zones of the cornea as well as corneal aberrations were stable during accommodation. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Purpose To determine the intrasubject repeatability of a recently introduced dual-camera rotating Scheimpflug–Placido imaging system (Galilei G4) in determining corneal thickness, power, and wavefront aberrations in young healthy subjects. Setting University of Valencia, Valencia, Spain. Design Prospective evaluation of diagnostic technology. Methods The study comprised right eyes of 25 subjects aged 20 to 40 years with a spherical equivalent ranging from −4.25 to +1.00 diopters. The central corneal thickness, thinnest point value and location, anterior and posterior surface curvatures, total corneal power, and corneal wavefront aberrations were measured for distance vision using the dual Scheimpflug–Placido system. Three consecutive measurements were taken in each eye. Results Twenty-five eyes were evaluated. Repeated-measures analysis of variance showed the only statistically significant difference between the 3 repeated measures to be in trefoil aberration. Intraclass correlation coefficients (ICCs) were higher than 0.950 for all the parameters except the thinnest point chord distance to geometric corneal center (0.528) and chord angle (0.742), corneal astigmatism (0.811) and its vector components J0 (0.891) and J45 (0.724), and all wavefront aberrations. Conclusions The new dual Scheimpflug–Placido system had high intraobserver repeatability for corneal power and thickness and moderate repeatability for corneal astigmatism and corneal wavefront aberrations in healthy corneas with low astigmatism. This iteration of the device performed better in young healthy corneas than preceding versions. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

El govern republicà no estigué a favor de l'ensenyament dirigit perreligiosos. El col·legi del Germans Maristes de Dénia fou tancat el 10 d'abril de1936 i aquell curs escolar acabà de manera clandestina. Amb l'eclat de la guerra i la situació de risc personal els maristes es dispersaren. El germà Millán, director del col·legi, aconseguí un salconduit per a viatjar en tren cap a Barcelona però fou detingut a Tavernes de Valldigna i empresonat i assassinat a Alzira.

Fundus autofluorescence (FAF) is a noninvasive imaging method to detect fundus endogenous fluorophores, mainly lipofuscin located in the retinal pigment epithelium (RPE). The FAF provides information about lipofuscin distribution and RPE health, and consequently an increased accumulation of lipofuscin has been correlated with ageing and development of certain retinal conditions. Areas covered: An exhaustive literature search in MEDLINE (via OVID) and PUBMED for articles related to ocular FAF in retinal diseases and different devices used for acquiring FAF imaging was conducted. Expert commentary: This review aims to show an overview about autofluorescence in the RPE and the main devices used for acquiring these FAF images. The knowledge of differences in the optical principles, acquisition images and the image post-processing between confocal scanning laser ophthalmoscopy and modified conventional fundus camera will improve the FAF images interpretation when are used as a complementary diagnosis and monitoring tool of retinal diseases.

We have reviewed a set of recently published studies that compared the anterior chamber depth (ACD) and/or white-to-white (WTW) distance obtained by means of different measuring devices. Since some of those studies reached contradictory conclusions regarding device interchangeability, this review was carried out in attempting to clarify which clinical devices can or cannot be considered as interchangeable in clinical practice to measure ACD and/or WTW distance, among these devices: A-scan, ultrasound biomicroscopy, Orbscan and Orbscan II (Bausch&Lomb Surgical Inc., San Dimas, California, USA), Pentacam and Pentacam HR (Oculus, Wetzlar, Germany), Galilei (Ziemer, Switzerland), Visante optical coherence tomography (Visante OCT, Carl Zeiss Meditec Inc., Dublin, California, USA), IOLMaster (Carl Zeiss Meditec, Jena, Germany), and Lenstar LS 900/Biograph (Haag-Streit AG, Koeniz, Switzerland/Alcon Laboratories Inc., Ft Worth, Texas, USA).

PURPOSE: To assess the precision of the new high-resolution optical coherence tomography (OCT) device to measure anterior segment distances and assess its agreement with a Scheimpflug camera. METHODS: Eighty patients with healthy and phakic eyes were included in this study, and only one eye per participant was analyzed. Each eye was measured three times with the Sirius topographer (Costruzione Strumenti Oftalmici, Florence, Italy) and the Cirrus HD-OCT 5000 (Carl Zeiss Meditec, Jena, Germany). RESULTS: On average, the Sirius topographer measured statistically significantly (P < .05) deeper ACD (approximately 0.07 mm), larger angle-to-angle distance (approximately 0.30 mm), thicker pachymetry (approximately 11 µ m), and wider temporal angle (approximately 6°) than the Cirrus OCT. Nevertheless, the Cirrus OCT measured statistically significantly (P < .05) wider nasal angle (approximately 2°) than the Sirius topographer. The repeatability and reproducibility metrics were similar between devices to measure the ACD (smaller than 0.05 mm), corneal pachymetry (smaller than 5 µ m), and anterior chamber angles (smaller than 5 degrees). Nevertheless, the reproducibility of the Cirrus OCT to measure the angle-to-angle distance was worse than the Sirius topographer, which had values of 0.11 and 0.21 mm, respectively. CONCLUSIONS: The Cirrus OCT and Sirius topographer showed good precision outcomes to measure the anterior segment of the eye. Nevertheless, clinical criteria are needed to judge whether these devices could be used interchangeably. [ J Refract Surg. 2016;32(11):766–772.]

La presbicia se define como una reducción lenta, natural, irreversible, y relacionada con la edad de la máxima amplitud de acomodación, suficiente como para causar síntomas de borrosidad y astenopia en visión próxima. Afortunadamente, se han desarrollado varios sistemas ópticos que mejoran esta sintomatología y ayudan a recuperar las capacidades visuales para trabajar en visión próxima. Por otro lado, el análisis in-vitro permite obtener resultados objetivos de los sistemas ópticos y así ampliar el conocimiento del rendimiento óptico de estos sistemas. La presente tesis doctoral estudia la calidad óptica in-vitro de lentes de contacto e intraoculares. Se utilizaron dos sistemas in-vitro para la evaluar la calidad óptica de lentes de contacto e intraoculares. Por un lado se utilizó un sistema óptico basado en la deflectometría cuantitativa, para medir el perfil de potencia de lentes de contacto blandas y lentes de contacto esclerales. Tal y como indica la ‘international organization for standardization’, las lentes de contacto blandas han de sumergirse 24 horas antes en el mismo líquido con el que se van a medir. De esta forma, se consiguen una estabilización del índice de refracción, y por tanto la medida de la potencia y calidad óptica son más precisas. Además, este equipo también se utilizó para medir la calidad óptica de lentes esclerales y lentes fáquicas de segmento posterior. En todos estos estudios, las lentes se colocaron con su cara posterior hacia abajo, tal y como exige el diseño del instrumento. Por otro lado, se utilizó otro sistema óptico para medir la función de transferencia de modulación de varias lentes intraoculares a diferentes vergencias. En este sistema se utilizó luz verde, y cada una de las lentes se tuvo que colocar con su cara posterior hacia arriba tal y como lo exige el diseño del instrumento. A partir de los resultados obtenidos se puede concluir que por un lado, la técnica basada en la deflectometría cuantitativa resultó ser adecuada para la medida del perfil de potencia de las lentes de contacto porque los resultados de repetibilidad eran altos y homogéneos a lo largo de la zona óptica. Así mismo, se encontraron diferencias en la calidad óptica entre los materiales con el que se fabrican lentes de contacto, aunque se precisan estudios in-vivo para comprobar el impacto clínico que estas diferencias puedan tener. Sin embargo, las fluctuaciones en el perfil de potencia de las lentes esclerales son pequeñas, y además, las diferencias en la calidad óptica entre las potencias de un mismo diseño sin insignificantes. Por otro lado, las lentes fáquicas de segmento posterior mostraron buena calidad óptica in-vitro a pesar de las diferencias en el diámetro de la zona óptica. Por esto, pacientes con diámetros pupilares grandes se podrían beneficiar de la implantación del nuevo diseño. En último lugar, los resultados in-vitro de las lentes que se han medido podrían ayudar a entender mejor el rendimiento óptico de cada una de ellas. Desde un punto de vista clínico, estos resultados podrían ayudar a seleccionar la lente de forma objetiva teniendo en cuenta los requerimientos visuales de cada paciente. Es decir, la selección de la lente se podría hacer de manera totalmente personaliza con el objetivo de mejorar la satisfacción del paciente.

To evaluate the optical quality of the Visian Implantable Collamer Lens (ICL) for different powers and pupil diameters. Wavefront aberrations of the −3, −6, −9, −12 and −15 diopters (D) V4b ICLs were measured at 3- and 4.5-mm pupils. The root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. In addition, modulation transfer function (MTF) of the five ICL powers was measured for a 3-mm pupil. The point spread functions (PSFs) of each ICL evaluated was calculated from the wavefront aberrations at 4.5-mm pupil. The ICLs evaluated had negative spherical aberration and negligible amounts of other aberrations. The negative spherical aberration increases when the ICL power increases being related with its innate optical properties. At 3-mm pupil, no statistically significant differences between ICLs were found for all the Zernike coefficient RMS values analyzed (p > 0.05). At 4.5-mm pupil, significant RMS values for the spherical aberration and total HOAs were found between medium-low and high powers (p

Purpose To assess nuclear and cortical opacities through the objective analysis of Scheimpflug images, and to check the correlation with the Lens Opacity Classification System III (LOCS III). Methods Nuclear and cortical opacities were graded according to the LOCS III rules after pupil dilation. The maximum and average pixel intensity values along an elliptical mask within the lens nucleus were taken to analyse nuclear cataracts. A new metric based on the percentage of opaque pixels within a region of interest was used to analyse cortical cataracts. The percentage of opaque pixels was also calculated for half, third and quarter areas from the region of interest’s periphery. Results The maximum and average intensity values along the nucleus were directly proportional to the LOCS III grade: The larger the LOCS III value, the larger maximum and average intensity ones. These metrics showed a positive and significant correlation with the LOCS grade: The larger the LOCS grade, the higher was percentage of opaque pixels along the cortex within the same mask’s size. This metric showed a significant correlation to the LOCS grade. Conclusion The metrics used to assess nuclear opacities showed good correlation with the LOCS III. The percentage of opaque pixels showed to be a useful metric to measure objectively the severity of the cortical opacity. These metrics could be implemented in an algorithm to detect and grade lens opacities automatically and objectively.

Purpose Develop an automatic system for cataract classification using the Sirius Scheimpflug for both nuclear and cortical cataract. Methods Scheimpflug images were taken using the Sirius system in 50 patients with nuclear and/or cortical cataract (mean age 69 ± 9.2 years). The nuclear opacity (NO) and cortical opacity was graded by an ophthalmologist according to the Lens Opacities Classification System (LOCSIII) by comparing the slit-lamp image with the LOCS's standard nuclear images. A custom-made MATLAB program was used to calculate the pixel intensity value within a region of interest (ROI) of the nucleus and to calculate the percentage of opaque pixels in the cortex. Results Eighty-nine eyes with nuclear and 81 eyes with cortical cataract were analysed. Both average and maximum NO pixel intensity units obtained from the ROI had a significant correlation with LOCS III (r = 0.731; P

Purpose To evaluate the optical quality of 3 multifocal intraocular lenses (IOLs): the Mini Well Ready progressive multifocal aspheric IOL, the AT LISA trifocal diffractive IOL, and the Finevision full diffractive trifocal IOL. Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods An instrument designed for measuring real-time modulation transfer function (MTF) and IOL power was used to measure the optical quality of each IOL for 3.0 mm and 4.5 mm apertures. This instrument measures both sagittal and tangential MTFs. The optical quality of each IOL was evaluated with the MTF, through-focus MTF, defocus tolerance, Strehl ratio MTF, and relative percentage of light in each focus. These metrics were evaluated at best focus for each IOL. Results Through-focus graphs corresponding to trifocal IOLs showed 3 mean peaks. Nevertheless, the progressive multifocal aspheric IOL showed 2 main areas, 1 corresponding to distance vision focus and the other including both intermediate and near vision foci. Conclusions The results obtained in the present study suggest that the progressive multifocal aspheric IOL might be considered for cataract surgery. Financial Disclosure None of the authors has a financial or proprietary interest in any method or material mentioned.

Purpose To assess the effect of different disposable soft contact lenses on several corneal parameters–-thickness, anterior and posterior curvature, and volume–-by means of a Scheimpflug imaging-based device (Pentacam HR). Diurnal variations of these parameters were taken into account. Methods Twenty-one young, healthy subjects wore 4 different types of daily disposable soft contact lenses on 4 different days: Dailies AquaComfort Plus, SofLens, Dailies Total1, and Acuvue TruEye. The lenses had different material and water content. Pachymetry and curvature maps and corneal volume values were obtained using the Pentacam HR twice a day: one before putting the lens on and one after an 8-hour period of contact lens wear. Measurements were also taken without any contact lenses being worn. Results Regarding corneal thickness, the lens with the most similar behavior to the naked eye scenario was the Dailies Total1, causing a thickening of 0.2 ± 0.1% in the central zone and 0.6 ± 0.2% in the periphery. All 4 lenses caused a slight but not significant flattening in the anterior corneal curvature, whereas the posterior corneal curvature only experienced a significant but small steepening with the SofLens. The use of these lenses increased corneal volume slightly. Conclusions Variations in corneal parameters seem to depend on the type of contact lens used (material, oxygen transmissibility, water content). However, the magnitude of the changes introduced by the use of soft contact lenses over the 8-hour period was small and probably not large enough to influence either visual acuity or comfort.

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.

The aim was to study the interchangeability of various devices that measure anterior chamber depth (ACD) and white-to-white (WTW) distance.Eighty right eyes of eighty patients aged 20 to 40 years were included. Their spherical equivalent ranged from -4.25 to +1.00 dioptres. Each eye's ACD and the WTW distance were measured using the following devices: a Castroviejo surgical calliper, CA-200F Corneal Analyser, Orbscan II, Pentacam HR and IOLMaster 500.The Pentacam HR measured significantly greater ACD (p0.01) than the other two devices, whereas IOLMaster 500 and Orbscan II yielded comparable (p0.01) distances. Nonetheless, in every device comparison, the mean difference was within clinically acceptable limits. The device comparison showed that for WTW distance measurements IOLMaster 500 yields the greatest value (p0.01), whereas CA-200F Corneal Analyser yields the smallest one (p0.01).Pentacam HR, Orbscan II and IOLMaster 500 can be used interchangeably to measure ACD, whereas Orbscan II, IOLMaster 500, Castroviejo surgical calliper and CA-200F Corneal Analyser cannot be considered interchangeable, when it comes to measuring WTW distance.

Purpose: To compare the ocular anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, as measured with two different Scheimpflug imaging devices. Methods: This transversal study included 80 right eyes from 80 subjects aged from 20 to 40 years. Their spherical equivalents ranged from -4.25 to +1.00 diopters (D). Each eye's anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, were measured for far vision using both the Galilei G4 (double Scheimpflug camera) and the Pentacam HR (single Scheimpflug camera) systems. Results: Mean anterior chamber depths were calculated as 3.12 ± 0.23 mm and 3.19 ± 0.24 mm when measured with the Galilei G4 and the Pentacam HR, respectively. The mean white-to-white distance measured was 11.84 ± 0.31 mm and 11.90 ± 0.43 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Mean pupil diameters were measured as 3.22 ± 0.58 mm and 3.22 ± 0.52 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Finally, the mean anterior chamber angle was 34.30 ± 2.86 degrees when it was measured with the Galilei G4, and 39.26 ± 2.85 degrees when measured with the Pentacam HR. A comparative analysis revealed that the Galilei G4 yielded a significantly lower (P0.05) for both devices were obtained for the white-to-white distance measurements. Conclusion: The Galilei G4 and Pentacam HR Scheimpflug systems cannot be used interchangeably because they produce significant measurement differences.

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.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.Clariti 1-Day lens caused the greatest thickening in the central (8.9±2.8 μm; p0.01) and in the peripheral cornea (10.1±4.6 μm; p0.01), 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.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.

Purpose To study changes in the anterior chamber depth (ACD), anterior chamber angle, and pupil diameter with accommodation. Setting University of Valencia, Valencia, Spain. Design Evaluation of diagnostic technology. Methods A rotating Scheimpflug camera (Pentacam HR) was used to measure changes in the ACD, anterior chamber angle, and pupil diameter with accommodation. Peripheral ACD was measured at the corneal center and 2.0 mm away from it in the nasal, superior, temporal, and inferior directions. The anterior chamber angle was computed as the mean anterior chamber angle of the entire eye. All measurements were obtained with accommodation stimuli ranging from +1.0 to −4.0 diopters (D) in 1.0 D steps. Results Eighty subjects (80 eyes) aged 22 to 30 years were evaluated. The ACD did not vary significantly with accommodation in any location. The relative change was 3.67%, 3.65%, 3.67%, 5.66%, and 6.22% in the central, nasal, temporal, superior, and inferior locations, respectively. The central ACD values were significantly higher than the nasal, temporal, superior, and inferior values. The nasal ACD was significantly less than the central, temporal, and inferior ACD. Temporal versus inferior ACD and nasal versus superior ACD yielded similar values. No significant accommodation-related changes occurred in the anterior chamber angle or pupil diameter. Conclusions Although the ACD and anterior chamber angle remained stable with accommodation, the pupil diameter varied. Regarding location-dependent ACD variability, the nasal–superior areas were significantly shallower than the temporal–inferior areas. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

To measure angle kappa distance with Orbscan II and Galilei G4, and to evaluate possible variations in this value for different accommodation degrees.Angle kappa was measured using the Orbscan II and the Galilei G4 in the right eye of 80 patients aged from 20 to 40 years. This value was measured three times per eye and per device, and the average was retained. Angle kappa was measured for far vision using the Orbscan II and the Galilei G4 in a random order for each subject. The Galilei G4 was used to measure angle kappa as a function of accommodation, where the first measure started at +1 D and the vergence was changed until reaching -4 D, in 1 D steps. In both measures, the kappa distance was expressed in millimetres.At distance, the values of angle kappa were 0.43 ± 0.13 mm and 0.27 ± 0.15 mm measured with the Orbscan II and Galilei G4 systems respectively. Statistical significant differences were found (P 0.01). With regard to the angle kappa values obtained as a function of accommodation, the values were 0.25 ± 0.15 mm, 0.26 ± 0.15 mm, 0.30 ± 0.20 mm, 0.27 ± 0.15 and 0.26 ± 0.15 mm, for +1 D, -1 D, -2 D, -3 D and -4 D respectively. No statistical significant differences were found among 0 D and the other vergences evaluated (P 0.01).For far vision, Orbscan II measured significantly higher angle kappa values than Galilei G4, the mean difference being 0.16 ± 0.08 mm. For different accommodation levels, the kappa distance did not change significantly.

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.

Purpose To compare the optical and visual quality of a simulated Toric Implantable Collamer Lens (TICL) and a bioptics technique to treat high myopic astigmatism. Methods An adaptive optics visual simulator was used to simulate the vision after TICL implantation and a bioptics procedure from the wavefront aberration pattern for moderate and high-myopic astigmatism. Visual acuity (VA) at different contrasts and contrast sensitivity (CS) at 10, 20 and 25 cycles degree−1 were measured for 3 and 5-mm pupils. Modulation Transfer Function (MTF) and Point Spread Function (PSF) were calculated for a 5-mm pupil. Results At a 3-mm pupil we only found statistically significant differences in VA between the two simulated surgeries at low-contrast for moderate- and high-myopic astigmatism (p

Purpose. To compare optical and visual quality of the implantable Collamer lens (ICL) and laser in situ keratomileusis (LASIK) for myopia. Methods. An adaptive optics visual simulator (CRX1, Imagine Eyes, France) was used to simulate the vision after ICL implantation and LASIK procedure from the wavefront aberration pattern for -3 and -6 D. Monocular visual acuity (VA) at different contrasts and contrast sensitivity (CS) at 10, 20, and 25 cycles/degree (cpd) were measured for 3- and 5-mm pupils. Modulation transfer function (MTF) and point spread function (PSF) were calculated for a 5-mm pupil. Results. The ICL showed a MTF near of diffraction-limited MTF, but the post-LASIK of MTF worsened moving away from both curves. Statistically significant differences were found in VA between both procedures for all conditions (p0.05). For -3 D ICL and LASIK, we did not find statistically significant differences in CS between the procedures for both pupils and any spatial frequencies (p0.05). But for -6 D ICL and LASIK, the effect of aberrations became apparent, finding statistically significant differences in CS between both procedures for 2 pupils and all spatial frequencies evaluated (p0.05). In all cases optical and visual quality was better with the ICL procedure. Conclusions. Both ICL and LASIK procedures provide good optical and visual quality, although the ICL provides better outcomes, especially for large refractive errors and pupil sizes. These outcomes are due to the LASIK procedure inducing higher higher-order aberrations than ICL implantation.

Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro . To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were calculated from the wavefront aberrations at 3- and 4.5-mm pupil. Statistical Analysis: A Student's t -test for unpaired data was used for comparison between myopic and hyperopic ICLs. Results: Myopic ICLs showed negative spherical aberration, in contrast hyperopic ICLs showed positive spherical aberration, which increases when the ICL power increases, due to the innate optical properties of the lens. All ICLs evaluated had negligible amounts of other aberrations. We did not find statistical significant differences in any Zernike coefficient RMS values analyzed between myopic and hyperopic ICLs at 3- and 4.5-mm pupil ( P > 0.05). Conclusions: Myopic and hyperopic ICLs provide good and comparable optical quality for low to moderate refractive error. The ICLs evaluated showed values of wavefront aberrations clinically negligible to affect the visual quality after implantation.

To evaluate visual and optical quality of the implantable collamer lens for different powers and sizes of incision surgery.Prospective study in humans.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.At 3 mm pupil, no statistically significant differences were found between both incision sizes for any implantable collamer lens power, except for -15 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 -3 and -15 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 -3 and -6 D implantable collamer lens, but they did become apparent for -15 D implantable collamer lens for both incision sizes, all contrasts and spatial frequencies (P.05).The implantable collamer lens provides good optical and visual quality, although these outcomes decreased with large-incision surgery because of the increase of aberrations.