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Purpose: To assess the optical quality and halo formation of a beam-shaping extended depth-of-focus (EDOF) intraocular lens (IOL) (AcrySof IQ Vivity; Alcon Laboratories, Inc) with corneas of long-range spherical aberration (SA) such as those resulting from myopic laser ablations. Methods: The optical quality of the EDOF IOL and a reference monofocal IOL was evaluated with three corneas (A, B, and C, with SA =+0.135, +0.290, +0.540 µm, respectively, for a 5.15-mm pupil at the IOL plane). The through-focus modulation transfer function area (MTFa) curves were obtained between −5.00 and +2.00 diopters (D) defocus range. The halo was also assessed with the three corneas. Results: Through-focus MTFa curves for a 4.5-mm IOL pupil showed a slight decrease in the maximum MTFa value provided by the EDOF IOL compared to the monofocal IOL in the three corneal situations (A: 45.9 vs 38.6 units; B: 41.1 vs 33.1 units, and C: 26.9 vs 23.8 units). For the 3.0-mm pupil, the EDOF IOL also had lower maximum MTFa than the monofocal IOL; however, the depth-of-focus increased to −2.20 D. With corneas A and B, the halo induced was of low energy with both IOLs. With cornea C, the EDOF IOL created a much larger and intense halo. Conclusions: The EDOF IOL provided a good distance optical performance and an extended range of focus of approximately 2.00 D, with a halo of low intensity when evaluated with a corneal SA similar to the one induced by a low to moderate myopic ablation. With a high myopic ablation, the halo induced would be of considerable size and energy. [ J Refact Surg. 2023;39(2):95–102.]

PURPOSE: To evaluate the optical and clinical performance of an enhanced monofocal intraocular lens (IOL) (TECNIS Eyhance ICB00; Johnson & Johnson Vision) in patients with high hyperopia and a short axial length. METHODS: Power mapping, wavefront analysis, and the through-focus modulation transfer function area (TF-MTFa) were measured in vitro for three IOL powers (10.00, 20.00, and 30.00 diopters [D]). The clinical study included 22 patients with an axial length of less than 22.5 mm. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity and binocular defocus curve were evaluated 6 months postoperatively. RESULTS: For the three IOL powers, the power mapping revealed an increase in positive power from the periphery to the center of the lens, providing an extra positive correction of 1.00 D for a 2-mm pupil size. The TF-MTFa curves showed only a peak of maximum MTFa at the distance focus. As the pupil size became smaller, there was a focus extension effect, providing an extended depth of focus of up to −1.50 D for a 2-mm pupil size. No significant dependency of the IOL base power on the power profile, wavefront, or optical quality was found. The clinical outcomes showed that all patients achieved a binocular CDVA of 0.1 logMAR or better. The mean visual acuity was better than 0.1 logMAR between +0.50 and −1.50 D of defocus. At a vergence of −2.00 D, the visual acuity was 0.11 ± 0.13 logMAR. CONCLUSIONS: The monofocal enhanced IOL provided good distance optical and visual quality and optimal visual acuity up to an intermediate-near vision distance of 50 to 40 cm in patients with high hyperopia and a short axial length. [ J Refract Surg . 2022;38(9):572–579.]

PURPOSE: To assess the in vitro optical quality and halo formation of the AcrySof IQ Vivity intraocular lens (IOL) (Alcon Laboratories, Inc) and to evaluate the clinical outcomes in patients who had bilateral implantation of this IOL. METHODS: The optical quality was evaluated with the PMTF optical bench (Lambda-X). Through-focus modulation transfer function area (MTFa) curves between −5.00 and +2.00 diopters (D) were obtained for 3- and 4.5-mm pupil apertures. The halo was assessed in vitro with a test bench. The clinical study included 30 patients. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity and binocular defocus curve were evaluated 6 months postoperatively. RESULTS: The through-focus MTFa curve for the 4.5-mm pupil size showed only one peak at distance focus (38.4 units). For the 3-mm pupil size, the through-focus MTFa showed a lower peak of MTFa (28.9 units), located at −0.70 D, and an extended depth of focus up to −2.20 D. The halo formed was larger and more intense compared to a standard monofocal IOL. The clinical outcomes at 6 months revealed satisfactory visual acuity outcomes. All patients achieved a binocular CDVA of 0.1 logMAR or better. The mean visual acuity was better than 0.2 logMAR between +1.00 and −2.00 D of defocus. At a vergence of −2.50 D, the visual acuity was 0.31 ± 0.09 logMAR. CONCLUSIONS: The AcrySof IQ Vivity IOL provided good distance optical and visual quality and an extended range of focus of approximately 2.00 D, obtaining an optimal or functional visual acuity up to 50 to 40 cm. The halo formed was low intensity overall, but higher intensity than a monofocal IOL. [ J Refract Surg . 2022;38(3):168–176.]

Clinical relevance It is important to distinguish between visual acuity, optical quality and quality of vision when outcomes obtained with intraocular lenses are evaluated. These parameters, that includeobjective and subjective tests, should be assessed to obtain results that are not biased. Background To assess the difference in visual and optical quality between two monofocal intraocular lens models. Methods : This was a prospective, parallel and randomised clinical study conducted at Miranza IOA, a private clinic in Madrid, Spain. Sixty patients were implanted bilaterally, 30 per group, with two aspheric IOLs with induced spherical aberration of -0.27 µm for Group A and -0.20 µm for Group B. Visual outcomes obtained at 1 and 3 months after surgery included both uncorrected (UCVA) and corrected monocular distance visual acuity (DCVA), objective scattering index (OSI), modulation transfer function (MTF) cut-off, Strehl Ratio (SR), contrast sensitivity defocus curve (CSDC), intraocular lens spherical aberration (SA), and longitudinal chromatic aberration of the eye. Activity limitations in daily life were assessed using CatQuest-9SF questionnaire. Results There were statistically significant differences for DCVA (0.04 LogMAR; p = .008) and SR (0.03; p = .003) between groups. Outcomes related to CSDC showed statistically significant differences for vergences between -0.50 D and +1.00 D (3 mm pupil) and for vergences of 0.00 D and +0.50 D (4.5 mm pupil) between groups. Overall, Group A showed better results regarding visual and optical quality, including a lower longitudinal chromatic aberration result in comparison to Group B. Patient satisfaction evaluated with CatQuest-9SF showed that Group A achieved better outcomes, although the differences were statistically significant only for the ‘Reading text on television’ item (p = 0.027). Conclusions Both intraocular lens models showed excellent quantity of vision, optical and visual quality as well as high patient satisfaction. Despite this, the the Group A model provided slightly better outcomes than the Group B model. This study was partially funded by an unrestricted research grant from Johnson and Johnson Vision.

Objective: To compare visual quality in patients implanted with Tecnis® monofocal (ZCB00) and multifocal (ZMB00) intraocular lenses taking into account their optical quality measured in vitro with an eye model. Methods: In total, 122 patients participated in this study: 44 implanted with monofocal and 78 with multifocal intraocular lenses. Measurements of visual acuity and contrast sensitivity were performed. The optical quality of the intraocular lenses was evaluated in three image planes (distance, intermediate and near) using an eye model on a test bench. The metric considered was the area under the curve of the modulation transfer function. Results: Optical quality at the far focus of the monofocal intraocular lens (area under the curve of the modulation transfer function = 66.97) was considerably better than that with the multifocal lens (area under the curve of the modulation transfer function = 32.54). However, no significant differences were observed between groups at the distance-corrected visual acuity. Distance-corrected near vision was better in the multifocal (0.15 ± 0.20 logMAR) than that in the monofocal group (0.43 ± 0.21 logMAR, p Conclusion: Patients implanted with multifocal ZMB00 achieved a distance visual acuity similar to those implanted with monofocal ZCB00, but showed significantly better intermediate and near visual acuity. A correlation was found between intraocular lenses’ optical quality and patients’ visual acuity. Contrast sensitivity was very similar between the multifocal and monofocal groups.

Purpose: Compare subjective (Rx) and objective (ObjRx) refractions outcomes with two autorefractors models and an aberrometer in eyes implanted with a hydrophobic trifocal IOL (FineVision POD F GF, Physiol, Liége, Belgium) and a hydrophilic one (FineVision POD F, Physiol, Liége, Belgium). Methods: Prospective comparative cohort study, with 100 subjects randomly assigned to either the POD F group (n = 50) or the POD F-GF group (n = 50). Postoperative eye examinations at 1-month visit included seven result sets, one for each assessment method: Rx, AR (automated refraction measured with the autorefractor KR8800), WF-P (Zernike-coefficients-based objective refraction, photopic pupil size), WF-M (Zernike-coefficients-based objective refraction, mesopic pupil size), WF-4 (Zernike-coefficients-based objective refraction, 4 mm pupil), OPD-C (automated refraction measured with the aberrometer OPD in the central pupil/photopic conditions), and OPD-M (automated refraction measured with the aberrometer OPD under mesopic conditions). Results: Mean differences between ObjRx and Rx reached statistical significance for sphere and spherical equivalent (M) only with OPD-C in the POD F-GF group. All ObjRx methods showed significant differences with Rx in the POD F group, with some values differing by more than 0.50 D (-0.58 D in M for the WF-P). Bland Altman plots showed better agreement for the astigmatic components, and for sphere and spherical equivalents in both IOL groups measured with AR and OPD-M. Conclusions: None of the objective methods of refraction evaluated in this study were as reliable as the subjective refraction, irrespective of the lens material, but POD F-GF ObjRx seems to differ less with Rx than POD F ObjRx values. Award-winning

We mathematically analyze the phase-only hologram constructed by taking the phase corresponding to the linear combination of two weighted phase functions. We show that this phase-only hologram may be written as a new linear combination for the original phase functions with new weights. Expressions for the new weights are developed to control the performance of the hologram. Also, some nondesired new terms appear and are written in terms of the original phase functions. The particular case of a bifocal lens is analyzed.

PURPOSE: To test the performance of a new monofocal intraocular lens, intended to extend depth of focus (Tecnis Eyhance, ICB00; Johnson & Johnson Vision, Inc) (ICB-IOL), in comparison to a standard monofocal IOL (Tecnis 1-piece, ZCB00; Johnson & Johnson Vision, Inc) (ZCB-IOL) of the same platform and material. METHODS: Assessment of the optical performance of the two IOLs was made in vitro using an optical test bench with a model eye. The spherical aberration, modulation transfer function (MTF), and area under the MTF (MTFa) were obtained for pupil sizes ranging from 2 to 5 mm. Through-focus MTFa curves between −3.00 and +1.00 diopters (D) were obtained with three pupil sizes (2, 3, and 4.5 mm). Halo formation was also assessed for both lenses. RESULTS: The ICB-IOL had slightly worse optical quality at its best focus (ie, lower MTF scores at distance vision) and more negative spherical aberration than the ZCB-IOL for pupils ranging from 2 to 3 mm. The maximum of the through-focus MTFa curve of the ICB-IOL with a 2-mm pupil shifted to a myopic defocus of −0.50 D. For larger pupils (≥ 3.5 mm), there were no differences in spherical aberration, MTF scores, and halo energy between the two lenses. CONCLUSIONS: The new ICB-IOL is a modified monofocal lens with 0.50 D of additional power in its central 2-mm zone and more negative spherical aberration values, which induce a myopic shift of the maximum of optical quality and could improve intermediate vision. For pupils larger than 3.5 mm, there were no differences between IOLs. The new ICB-IOL design would produce photic phenomena comparable to a standard IOL. [ J Refract Surg . 2020;36(9):625–632.]

Automated cell counting in in-vivo specular microscopy images is challenging, especially in situations where single-cell segmentation methods fail due to pathological conditions. This work aims to obtain reliable cell segmentation from specular microscopy images of both healthy and pathological corneas. We cast the problem of cell segmentation as a supervised multi-class segmentation problem. The goal is to learn a mapping relation between an input specular microscopy image and its labeled counterpart, indicating healthy (cells) and pathological regions (e.g., guttae). We trained a U-net model by extracting 96×96 pixel patches from corneal endothelial cell images and the corresponding manual segmentation by a physician. Encouraging results show that the proposed method can deliver reliable feature segmentation enabling more accurate cell density estimations for assessing the state of the cornea.

Purpose To evaluate the changes in pupil diameter in women and men after cataract surgery. The correlation of pupillary changes with the variables age and anterior chamber depth will be analyzed. Methods The values of 109 randomized eyes who underwent cataract surgery were obtained and divided into two groups, 71 women and 38 men. Pupil diameter was measured preoperatively and 3-months postoperatively using the pupillometer software of the Topolyzer Vario (Wavelight Laser Technologie AG). Anterior chamber depth was obtained with Pentacam® (Oculus). Differences in pupillary diameters were investigated and correlations with age and anterior chamber depth were analyzed. Results For mesopic pupils, the male group had greater reduction in their postoperative pupillary diameter, -0.56 mm (-12.4%), than the female group, -0.38 mm (-8.2%), P = 0.025. Photopic postoperative pupils reduced to a lesser extent, yet more in men than in women (-0.11mm [-4.5%] vs. -0.04 [-1.6%], P = 0.048). Weak significant negative correlation was found between photopic pupillary changes in women with age (r = -0.24, P = 0.041), and positive correlation for mesopic pupillary changes in men with age (r = +0.34, P = 0.039). Conclusions Patients experience pupil reduction after cataract surgery in general, but more in men than in women and for both photopic and mesopic lighting conditions. The differences are statistically significant and have moderate clinical relevance. Concerning pupillary changes, weak but opposite sign correlations were found between male/female gender and age. This work was supported by the Spanish Ministerio de Economía y Competitividad and FEDERfunds under project Ref. DPI2016-76019-R

Universities, as educational service providers, must pay attention to their employees who are pivotal in delivering and communicating brand promise and service quality to the stakeholders. While branding initiatives most frequently focus on external stakeholders, internal branding efforts establish systems/processes and consequent employees’ behaviour that are consistent with external branding efforts. With a sample of 753 faculty members and researchers from a Spanish public University, the study aims to establish if employee tenure and job security have a significant relationship with employees’ brand commitment and employees’ brand supporting behaviour. An analysis of variance was carried out for testing the hypothesis. Differences were found according to tenure in employees’ brand commitment while job security did not impact significantly on employees’ brand commitment. In addition, a positive and significant relationship were found between employees’ brand supporting behaviour and tenure, but not for job security. For business practitioners, this research state that it is essential for service companies, such as universities, to use differing approaches to employees according to their organisational tenure as an important managerial implication.

© 2016 Elsevier Ltd. A novel nonlinear image encryption scheme based on a fully phase nonzero-order joint transform correlator architecture (JTC) in the Gyrator domain (GD) is proposed. In this encryption scheme, the two non-overlapping data distributions of the input plane of the JTC are fully encoded in phase and this input plane is transformed using the Gyrator transform (GT); the intensity distribution captured in the GD represents a new definition of the joint Gyrator power distribution (JGPD). The JGPD is modified by two nonlinear operations with the purpose of retrieving the encrypted image, with enhancement of the decrypted signal quality and improvement of the overall security. There are three keys used in the encryption scheme, two random phase masks and the rotation angle of the GT, which are all necessary for a proper decryption. Decryption is highly sensitivity to changes of the rotation angle of the GT as well as to little changes in other parameters or keys. The proposed encryption scheme in the GD still preserves the shift-invariance properties originated in the JTC-based encryption in the Fourier domain. The proposed encryption scheme is more resistant to brute force attacks, chosen-plaintext attacks, known-plaintext attacks, and ciphertext-only attacks, as they have been introduced in the cryptanalysis of the JTC-based encryption system. Numerical results are presented and discussed in order to verify and analyze the feasibility and validity of the novel encryption-decryption scheme.

This article studies the relationship between two metrics, the area under the modulation transfer function (MTFa) and the energy efficiency (EE), and their ability to predict the visual quality of patients implanted with multifocal intraocular lenses (IOLs). The optical quality of IOLs is assessed in vitro using two metrics, the MTFa and EE. We measured them for three different multifocal IOLs with parabolic phase profile using image formation, through-focus (TF) scanning, three R, G, B wavelengths, and two pupils. We analyzed the correlation between MTFa and EE. In parallel, clinical defocus curves of visual acuity (VA) were measured and averaged from sets of patients implanted with the same IOLs. An excellent linear correlation was found between the MTFa and EE for the considered IOLs, wavelengths and pupils (R2 > 0.9). We computed the polychromatic TF-MTFa, TF-EE, and derived mathematical relationships between each metrics and clinical average VA. MTFa and EE proved to be equivalent metrics to characterize the optical quality of the studied multifocal IOLs and also in terms of clinical VA predictability. Ministerio de Economía y Competitividad y fondos Feder (DPI2016-76019-R).

Purpose: To compare the chromatic performance of the Bausch & Lomb Versario 3F trifocal intraocular lens (IOL) with the PhysIOL FineVision MicroF trifocal IOL and the Johnson & Johnson Vision TECNIS Symfony ZXR00 extended range of vision (ERV) IOL. Methods: The through-focus energy efficiency (TF-EE) was measured in vitro with red (R), green (G), and blue (B) wavelengths and was used to obtain the focus powers and longitudinal chromatic aberrations (LCAs) for each IOL. Other metrics, derived from the RGB TF-EE curves, were assessed for a more complete description of the chromatic performance of the IOLs. Results: Both of the trifocal IOLs, although not specifically designed to tackle chromatic aberrations, showed acceptable LCA (=0.50 D) in all foci with more balanced R and B efficiencies of their foci. Despite having the lowest TF-EE value at all foci, the Versario 3F demonstrated the most balanced chromatic performance with the smoothest energy transition among all foci and the smallest chromatic span. The Symfony lens effectively reduced LCA at distance and intermediate foci (=0.36 D), despite the unbalanced and asymmetric R and B efficiencies at its foci. Conclusions: To fully describe the chromatic performance of an IOL it is necessary to take into account not only the LCA but also the RGB TF-EE and chromatic span. This comprehensive analysis suggests that, in comparison with the other IOLs under study, the Versario 3F lens might contribute to further mitigating the impact of chromatic aberration. Translational Relevance: The in vitro bench testing of the optical properties of modern presbyopia-correcting intraocular lenses (more specifically in this work, the polychromatic through-focus energy efficiency and longitudinal chromatic aberration) provides objective and complementary information that helps to interpret the visual quality outcomes of pseudophakic patients obtained in clinics. None of the authors has a financial or proprietary interest in any of the products or materials used in the study. Sources of financial support: public, the Spnaish Ministerio de Economía y Competitividad, and European-Union ERDF funds, under project Ref. No. DPI2016-76019-R and private, Bausch and Lomb Incorporated.

The optical quality of three multifocal intraocular lenses (MIOLs) was measured in vitro using the area under the modulation transfer function (MTFa) and energy efficiency (EE). We evaluated those metrics through-focus (TF) by axially scanning the image space with three wavelengths (R, G, B). High linear correlation between MTFa and EE was found for all cases. Correlations between optical in vitro results (polychromatic TF-MTFa and TF-EE) and clinical visual acuity (VA) defocus curves for the three MIOLs allowed us to derive mathematical expressions. Both metrics proved to be equivalent to predict postoperative VA. Spanish Ministerio de Economía y Competitividad y fondos FEDER (DPI2016-76019-R)

We propose a new encryption system based on a nonlinear joint transform correlator (JTC) using the information of two biometrics (one digital fingerprint for each user) as security keys of the encryption system. In order to perform the decryption and authentication in a proper way, it is necessary to have the two digital fingerprints from the respective users whose simultaneous authentication is pursued. The proposed security system is developed in the Fourier domain. The nonlinearity of the JTC along with the five security keys given by the three random phase masks and the two digital fingerprints of the two users allow an increase of the system security against brute force and plaintext attacks. The feasibility and validity of this proposal is demonstrated using digital fingerprints as biometrics in numerical experiments.

In the field of ophthalmology, retinal images are essential for the diagnosis of many diseases. These images are acquired with a device called the retinal camera. However, often small dust particles in the sensor produce image artifacts that can be confused with small lesions, such as micro-aneurysms. The digital removal of artifacts can be understood as an inpainting process in which a set of pixels are replaced with a value obtained from the surrounding area. In this paper, we propose a methodology based on the sparse representations and dictionary learning for the removal of artifacts in retinal images. We test our method on real retinal images coming from the clinical setting with actual dust artifacts. We compare our restoration results with a diffusion-based inpainting technique. Encouraging experimental results show that our method can successfully remove the artifacts, while assuring the continuity of the retinal structures, like blood vessels. © 2019 IEEE. CCD2018-U005 IEEE Colombia Section;IEEE Signal Processing Society Colombia Chapter;Universidad Industrial de Santander The authors acknowledge the financial support of Centre de Cooperació i Desenvolupament at the Univer-sitat Politècnica de Catalunya (project CCD2018-U005). Authors are grateful to J. L. Fuentes from the Miguel Servet University Hospital (Zaragoza, Spain) for providing images, and to E. Sierra for providing the code for inpainting by diffusion for the comparison experiments.

Two theoretical sinusoidal diffractive profile models to build up a trifocal intraocular lens (IOL) are analysed. Topographic features of the diffractive zones such as their shape, step height and radii, as well as the energy efficiency (EE) of the foci, depends on the particular model, and are compared to the ones experimentally measured in a trifocal lens that claims to be designed with a generic sinusoidal diffractive profile: the Acriva Trinova IOL (VSY Biotechnology, The Netherlands). The topography of the IOL is measured by confocal microscopy. The EE is experimentally obtained through-focus with the IOL placed in a model eye. The experimental results match very accurately with one of the theoretical models, the optimum triplicator, once that a spatial shift in the sinusoidal profile is introduced in the model.

We present a new experimental system for optical encryption using a nonlinear joint transform correlator (JTC) to implement the optical security technique of the double random phase encoding (DRPE). The DRPE, which is usually performed in a 4f-processor, encodes an image into a noisy distribution (encrypted image) by using two random phase masks (RPMs). In our experimental setup, the input plane of the JTC is fully encoded in phase and this plane contains two non-overlapping data functions (images). In the encryption step, the phase-encoded image to be encrypted and the two RPMs are placed in the input plane of the JTC with the purpose of obtaining the needed intensity distributions at the output plane to compute the encrypted image. The optical and numerical transformations are performed in the Fourier domain. A nonlinear operation is introduced to modify the joint power spectrum (JPS) of the JTC in order to reproduce exactly the same results of the DRPE. The experimental optical encryption scheme based on a three-step JTC is implemented by using an optoelectronic setup. The input plane of the JTC is optically implemented by means of a phase-only spatial light modulator (SLM). The decryption process is performed using a virtual optical system. Experimental and numerical results of the optical encryption and simulated decryption systems are presented, in order to show the feasibility of the proposed security system.

Accurate endothelial cell density with specular microscopy is essential for correct clinical assessment of the cornea. Commercial specular microscopes incorporate automated cell segmentation methods to estimate cell density. However, these methods are prone to false cell detections in pathological corneas. This project aims to obtain a reliable automated cell density from specular microscopy images of both healthy and pathological corneas with convolutional neural networks. Convolutional neural networks require labeled datasets. Thus, we developed custom software for producing a curated dataset of labeled ground-truth images and cell density maps. In this paper, we implemented a fully convolutional regression network to predict the cell density map from the input microscopy image. Encouraging preliminary results show the potential of the method. This approach may pave the way for dealing with the variability of corneal endothelial cell images.

In this work, the occlusion and noise test on the encrypted image produced by a joint transform correlator-based encryption system in the Fresnel domain (FrD) are computed and presented, in order to check the performance of this security system with respect to the image quality resulting in the decryption process for the retrieved image. The encryption system based on a joint transform correlator (JTC) in the FrD was proposed by us, with the purpose of using a lensless optical setup. We test the performance of this security system when the encrypted image is affected by common sources of degradation such as noise (additive and multiplicative) or partial occlusion. Finally, we evaluate the performance and robustness of the security system in the FrD by using the metric of the root mean square error (RMSE) between the image to encrypt and the decrypted image when the encrypted image is degraded by noise or modified by occlusion. This research has been funded by the Universidad de La Guajira, Colombia, and the Spanish Ministerio de Ciencia e Innovación and Fondos FEDER (Project DPI2013-43220-R).

Retinal images are acquired with eye fundus cameras which, like any other camera, can suffer from dust particles attached to the sensor and lens. These particles impede light from reaching the sensor, and therefore they appear as dark spots in the image which can be mistaken as small lesions like microaneurysms. We propose a robust method for detecting dust artifacts from more than one image as input and, for the removal, we propose a sparse-based inpainting technique with dictionary learning. The detection is based on a closing operation to remove small dark features. We compute the difference with the original image to highlight the artifacts and perform a filtering approach with a filter bank of artifact models of different sizes. The candidate artifacts are identified via non-maxima suppression. Because the artifacts do not change position in the images, after processing all input images, the candidate artifacts which are not in the same approximate position in different images are rejected and kept unchanged in the image. The experimental results show that our method can successfully detect and remove artifacts, while ensuring the continuity of retinal structures, such as blood vessels. © 2019 SPIE. Downloading of the abstract is permitted for personal use only. Universitat Politècnica de València, UPV ARC Centre of Excellence in Cognition and its Disorders, CCD The Society of Photo-Optical Instrumentation Engineers (SPIE) The authors acknowledge the financial s upport f rom t he C entre d e C ooperació i D esenvolupament (CCD) at the Universitat Politècnica de Catalunya under project ref. CCD2018-U005, and from the Universidad Tec-nológica de Bol´ıvar. Authors are grateful to Juan Lu´ıs Fuentes from the Miguel Servet University Hospital (Zaragoza, Spain) for providing the images.

The optical quality of a set of IOLs (modeling set: one monofocal and two bifocals) was assessed through focus by the area under the modulation transfer function (MTFa) metric and related to the visual acuity (VA) defocus curves of pseudophakic patients implanted with said IOLs. A non-linear relationship between the MTFa and clinical VA was obtained with an asymptotic limit found to be the best VA achievable by the patients. Two mathematical fitting functions between clinical VA and MTFa were derived with high correlation coefficients (R2≥0.85). They were applied to the MTFa obtained from a different set of IOLs with advanced designs (trial set: one extended range of vision –ERV-, one trifocal ERV and one trifocal apodized) to predict VA versus defocus of patients implanted with these IOLs. Differences between the calculated VA and the clinical VA for both fitting models were within the standard deviation of the clinical measurements in the range of -3.00 D to 0.00 D defocus, thus proving the suitability of the MTFa metric to predict clinical VA performance of new IOL designs.

Background Continuous aspiration of subglottic secretions is effective in preventing ventilator-associated pneumonia, but it involves a risk of mucosal damage. The main objective of our study was to determine the incidence of airway complications related to continuous aspiration of subglottic secretions. Methods In consecutive adult patients with continuous aspiration of subglottic secretions, we prospectively recorded clinical airway complications during the period after extubation. A multidetector computed tomography of the neck was performed during the period of 5 days following extubation to classify subglottic and tracheal lesions as mucosal thickening, cartilage thickening or deep ulceration. Results In the 86 patients included in the study, 6 (6.9%) had transient dyspnea, 7 (8.1%) had upper airway obstruction and 18 (20.9%) had dysphonia at extubation. Univariate analysis identified more attempts required for intubation (2.3 ± 1.1 vs. 1.2 ± 0.5; p = 0.001), difficult intubation (71.4 vs. 10.1%, p = 0.001) and Cormack score III–IV (71.4 vs. 8.8%; p

We present the results of the noise and occlusion tests in the Gyrator domain (GD) for a joint transform correlator-based encryption system. This encryption system was recently proposed and it was implemented by using a fully phase nonzero-order joint transform correlator (JTC) and the Gyrator transform (GT). The decryption system was based on two successive GTs. In this paper, we make several numerical simulations in order to test the performance and robustness of the JTC-based encryption-decryption system in the GD when the encrypted image is corrupted by noise or occlusion. The encrypted image is affected by additive and multiplicative noise. We also test the effect of data loss due to partial occlusion of the encrypted information. Finally, we evaluate the performance and robustness of the encryption-decryption system in the GD by using the metric of the root mean square error (RMSE) between the original image and the decrypted image when the encrypted image is degraded by noise or modified by occlusion.

The inflammatory response depends on several factors, including pathogenicity and duration of the stimulus, and also on the balance between inflammatory and antiinflammatory response. Several studies have presented evidence of the importance of genetic factors in severe infections. The innate immune response prevents the invasion and spread of pathogens during the first hours after infection. Each of the different processes involved in innate immunity may be affected by genetic polymorphisms, which can result in susceptibility or resistance to infection. The results obtained in the different studies do not irrefutably prove the role or function of a gene in the pathogenesis of respiratory infections. However, they can generate new hypotheses, suggest new candidate genes based on their role in the inflammatory response, and constitute a first step in understanding the underlying genetic factors.

La respuesta inflamatoria del huesped viene determinada por la virulencia del microorganismo, la duracion del estimulo y el equilibrio entre la respuesta inflamatoria y la antiinflamatoria. Diversos estudios han mostrado la importancia de la genetica en las infecciones graves. La respuesta inmune innata es el mecanismo que impide la invasion y propagacion de microorganismos durante las primeras horas tras la infeccion. Cada uno de los procesos implicados en la respuesta innata puede alterarse por polimorfismos de los genes implicados, pudiendo esto resultar en una mayor susceptibilidad o resistencia a la infeccion. Los resultados obtenidos en los diferentes estudios geneticos no prueban de forma irrefutable el papel o la funcion de un gen en la patogenesis de la infeccion respiratoria. Sin embargo, permiten generar nuevas hipotesis, indican nuevos genes candidatos en base a su papel en la respuesta inflamatoria y proporcionan el primer paso en la comprension de los factores geneticos subyacentes.

Background Comatose patients present a high risk of early-onset ventilator-associated pneumonia (EO-VAP) for which antibiotic prophylaxis has been proposed. Comatose patients were studied to evaluate the efficacy of a single-dose of antibiotic prophylaxis at intubation against EO-VAP. Methods A prospective cohort of comatose patients (Glasgow Coma Score ≤ 8) who were admitted in 2009-2010 and administered a single-dose of antibiotic within 4 h of intubation was compared with comatose patients (admitted ≥ 4 h after intubation in 2009-2010 or admitted in 2007-2008) who did not receive antibiotic prophylaxis. We analyzed the incidence of EO-VAP, late-onset VAP, and ventilator-associated tracheobronchitis in both groups. Propensity scores for receiving antibiotic prophylaxis were derived on the basis of patients' characteristics (eg, age and severity) to assess its impact on EO-VAP development. Results We included 129 patients (71 in the prophylaxis group and 58 in the control group). The global incidence of VAP and incidence of EO-VAP were lower in the prophylaxis group: 10.8 vs 28.4 episodes/1,000 days on mechanical ventilation (P = .015) and 4.4 vs 23.1 episodes/1,000 days on mechanical ventilation (P = .02), respectively. The incidence of late-onset VAP did not differ. The prophylaxis group tended toward lower incidence of ventilator-associated tracheobronchitis (15.5% vs 25.9%, P = .14). No differences in mortality were found between groups. The propensity-score regression analysis confirmed that a single dose of antibiotic prophylaxis was independently associated with lower incidence of EO-VAP (OR, 0.11; 95% CI, 0.02-0.58; P = .009). Conclusions A single dose of antibiotic prophylaxis at intubation might lower the incidence of EO-VAP. However, a randomized clinical trial should be conducted to confirm our findings.

We describe a first-and-second-diffractive-order intraocular lens ((1st,2nd)DIOL) within the class of hybrid refractive-diffractive designs for intraocular lenses (IOLs) and analyse its properties of focus extension and compensation of longitudinal chromatic aberration (LCA), particularly for lenses with low addition. Power, energy efficiency and their wavelength dependence are extended from monofocal IOL and conventional bifocal zeroth-and-first-diffractive-order IOL ((0th,1st)DIOL) to (1st,2nd)DIOL of low addition. Compensation of LCA is experimentally assessed in optical bench through the through-focus energy efficiency of three Tecnis IOLs with red, green and blue illuminations: ZA9003 (monofocal), ZKB00 (bifocal (0th,1st)DIOL with + 2.75 D add) and Symfony ZXR00. We prove Tecnis Symfony ZXR00 IOL can be considered an example of (1st,2nd)DIOL design of low addition, with LCA compensation in both the distance and intermediate foci, whereas the bifocal (0th,1st)DIOL does not compensate in the distance focus. However, the energy efficiency of (1st,2nd)DIOL for wavelengths other than the design wavelength is markedly more asymmetric.