23 research outputs found

    Clinical assessment of chromatic aberration in phakic and pseudophakic eyes using a simple autorefractor

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    We describe a psychophysical method and a simple setup – an autorefractor with a Scheiner disc, sequentially illuminated with red and blue lights – for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic patients. This method applies to the unaccommodated eye, even in the presence of positive or negative refractive errors and astigmatism. It measures the chromatic difference of refraction as an estimate of LCA. We built a proof of concept from inexpensive and off-the-shelf optomechanical components with which we obtained the preliminary clinical results presented in the paper. We considered one control group of phakic patients and three groups of pseudophakic patients with monofocal implants of different designs and materials. The results, satisfactory and consistent with those reported by other researchers in related works, demonstrate the method and system feasibility.Peer ReviewedPostprint (published version

    Clinical assessment of chromatic aberration in phakic and pseudophakic eyes

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    We present a psychophysical method and a simple setup for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic eyes. A proof of concept built from inexpensive and non-sophisticated optomechanical components were used to obtain the preliminary clinical results presented in this workPeer Reviewe

    Clinical assessment of chromatic aberration in phakic and pseudophakic eyes

    No full text
    We present a psychophysical method and a simple setup for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic eyes. A proof of concept built from inexpensive and non-sophisticated optomechanical components were used to obtain the preliminary clinical results presented in this workPeer ReviewedPostprint (published version

    Clinical assessment of chromatic aberration in phakic and pseudophakic eyes

    No full text
    We present a psychophysical method and a simple setup for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic eyes. A proof of concept built from inexpensive and non-sophisticated optomechanical components were used to obtain the preliminary clinical results presented in this workPeer Reviewe

    Texture mapping met minimale vervorming op een drie dimensionaal object

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    KULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainSIGLEBEBelgiu

    Pre-operative simulation of post-operative multifocal vision

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    While multifocal intraocular lenses (MIOLs) are increasingly implanted to correct for presbyopia, how one sees with a multifocal correction is hard to explain and imagine. The current study evaluates the quality of various visual simulating technologies by comparing vision with simulated MIOLs pre-operatively and the implanted MIOLs post-operatively in the same patients. Two simulation platforms were used: (1) a custom-developed adaptive optics (AO) system, with two visual simulator devices: a spatial light modulator (SLM) and an optotunable lens operating under temporal multiplexing (SimVis); and (2) a wearable, binocular, large field of view SimVis2Eyes clinical simulator (SimVis Gekko, 2Eyes Vision, Madrid, Spain). All devices were programmed to simulate a trifocal diffractive MIOL (POD F, FineVision, PhysIOL). Eight patients were measured pre-operatively simulating the trifocal lens and post-operatively with implantation of the same MIOL. Through-focus decimal visual acuity (TF VA) was measured (1) monocularly in monochromatic light using a four-alternative-forced-choice procedure in the AO system, and (2) binocularly using a clinical optotype in white light. Visual simulations pre-operatively predict well the TF VA performance found post-operatively in patients implanted with the real IOL. The average RMS difference between TF curves with the different visual simulators was 0.05 ± 0.01. The average RMS difference between the TF VA curves with the SimVis pre-operatively and the real MIOL post-operatively was 0.06 ± 0.01 in both platforms, and it was higher in cataract eyes (0.08 ± 0.01, on average across simulators) than in eyes with clear lens. In either group, the shape of the TF curves is similar across simulators and pre-and post-operatively. TF curves cross-correlated significantly between simulators (lag k = 0, rho = 0.889), as well as with results with the real MIOL implanted (lag k = 0, rho = 0.853). Visual simulations are useful programmable tools to predict visual performance with MIOLs, both in an AO environment and in a clinical simulator. Pre-operative visual simulations and post-operative data are in good agreement.European Research CouncilH2020 Marie Skłodowska-Curie ActionsGobierno de EspañaPhysIOL Group (Bélgica)Depto. de Optometría y VisiónFac. de Óptica y OptometríaTRUEpu

    Association of Alk1 and Endoglin Polymorphisms with Cardiovascular Damage

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    © The Author(s) 2020.Cardiovascular diseases are associated to risk factors as obesity, hypertension and diabetes. The transforming growth factor-β1 receptors ALK1 and endoglin regulate blood pressure and vascular homeostasis. However, no studies relate the association of ALK1 and endoglin polymorphisms with cardiovascular risk factors. We analysed the predictive value of the ALK1 and endoglin polymorphisms on cardiovascular target organ damage in hypertensive and diabetic patients in 379 subjects with or without hypertension and diabetes in a Primary Care setting. The ALK1 rs2071219 polymorphism (AA genotype) is associated with a lower presence of diabetic retinopathy and with the absence of altered basal glycaemia. Being carrier of the ALK1 rs3847859 polymorphism (G allele) is associated with lower basal heart rate and with higher LDL-cholesterol levels. The endoglin rs3739817 polymorphism (AA genotype) is associated with higher levels of LDL-cholesterol, and being carrier of the endoglin rs10987759 polymorphism (C allele) is associated with higher haemoglobin levels and with an increased heart rate. Summarizing, several ALK1 and endoglin gene polymorphisms increase the risk of cardiovascular events. The analysis of these polymorphisms in populations at risk, in combination with the determination of other parameters and biomarkers, could implement the diagnosis and prognosis of susceptibility to cardiovascular damage.This work was supported by grants from Instituto de Salud Carlos III: Ministry of Economy and Competitiveness, PI15/01055, PI18/00996 and RETICS RD016/0009/0025 (REDINREN), co-funded by FEDER

    Clinical assessment of chromatic aberration in phakic and pseudophakic eyes using a simple autorefractor

    No full text
    We describe a psychophysical method and a simple setup – an autorefractor with a Scheiner disc, sequentially illuminated with red and blue lights – for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic patients. This method applies to the unaccommodated eye, even in the presence of positive or negative refractive errors and astigmatism. It measures the chromatic difference of refraction as an estimate of LCA. We built a proof of concept from inexpensive and off-the-shelf optomechanical components with which we obtained the preliminary clinical results presented in the paper. We considered one control group of phakic patients and three groups of pseudophakic patients with monofocal implants of different designs and materials. The results, satisfactory and consistent with those reported by other researchers in related works, demonstrate the method and system feasibility.Peer Reviewe

    Correlation between polychromatic image quality metrics to predict visual acuity in pseudophakic patients

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    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 EconomĂ­a y Competitividad y fondos FEDER (DPI2016-76019-R)Peer ReviewedPostprint (published version
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