Search results for "OPTICS"
showing 10 items of 10033 documents
Preliminary in vivo positional analysis of a posterior chamber phakic intraocular lens by optical coherence tomography and its correlation with clini…
2012
Purpose: To analyze by spectral-domain optical coherence tomography the anatomical relationship of a specific type of posterior chamber phakic intraocular lens (pIOL) implanted in cases of high to moderate myopia with the adjacent intraocular structures and to correlate it with clinical outcomes. Methods: Prospective observational case series including 18 eyes with high to moderate myopia (spherical equivalent between −5.88 and −15.75 D) of 9 patients (age range, 29–49 years) undergoing bilateral Phakic Refractive Lens (PRL, Zeiss) implantation. Postoperative visual acuity, refraction, contrast sensitivity (CS), and ocular higher order aberrations (HOA) were evaluated. Furthermore, the in v…
Anterior chamber depth measurement in teenagers. Comparison of two techniques
2013
Purpose: The aim of this study is to determine the anterior chamber depth (ACD) in teenagers using two different devices: partial coherence interferometry IOLMaster (Carl Zeiss Meditec) and anterior segment optical coherence tomography (Visante TM OCT, Carl Zeiss Meditec) and to evaluate the degree of agreement between ACD measurements carried out by both instruments. Methods: In this prospective study 68 eyes of 34 emmetropic Caucasic patients (18 girls and 16 boys) were analysed. ACD was measured from the anterior corneal surface to anterior surface of the crystalline lens. For each age the ACD size was calculated and the difference between IOLMaster and Visante-OCT measurements was analy…
New Forceps and Spatula for Easy Retropupillary Implantation of Iris Claw Lenses in Aphakia: Experience in 4 Years of Use
2008
PURPOSE. Retropupillary implantation of an iris claw lens offers a rapid and atraumatic approach for rehabilitation of aphakic eyes. The difficulty in the implantation process arises because of the possibility of losing the intraocular lens (IOL) into the vitreous cavity and the need to change the hand holding the forceps during the enclavation. M ETHODS. The new forceps design radically changes the method of grasping an IOL. It contains an extendable supporting plate with a hook-like end. The instrument achieves a horizontal three-point fixation at the edge of the implant in the 6 and 12 o’clock position in order to prevent slippage into the vitreous cavity during the inclination. The supp…
Visual Performance after AcrySof ReSTOR Aspheric Intraocular Lens Implantation
2008
Purpose: To evaluate distance, intermediate and near visual performance in patients who had undergone implantation of the multifocal aspheric AcrySof ReSTOR intraocular lens (IOL). Methods: Binocular best distance corrected visual acuity (BCVA) at high and low contrast [4 m], best distance corrected near visual acuity (BCNVA) [40 cm], intermediate visual acuity [80 and 60 cm], and distance contrast sensitivity (CS) under photopic [85 cd/m2] and mesopic [3 cd/m2] conditions, were measured in 36 eyes that underwent implantation of the AcrySof ReSTOR Aspheric IOL (SN6AD3). Results: At the 3-month postoperative visit, binocular BCVA was -0.058±0.091, 0.200±0.079, and 0.258±0.071 logMAR, for 100…
RGB mapping of hemoglobin distribution in skin
2011
An experimental RGB imaging system based on commercial color camera was constructed, and its potential for mapping of hemoglobin distribution in skin was studied. Two types of LEDs (RGB and white “warm” LEDs) were compared as illuminators for acquiring images of vascular and pigmented skin malformations. A novel approach for studies of skin capillary refill by RGB analysis has been proposed and discussed.
Effects of a low-power He-Ne laser on the healing of experimental colon anastomoses: our experience
1992
Despite technical advances, the incidence of anastomotic leaks in elective colorectal surgery remains around 14%. Recent studies suggest that the use of low-energy lasers may enhance wound healing in different tissues in a selective, nondestructive manner. Based on these findings we have attempted to provide experimental background on the effects of a He-Ne laser during the early stages of healing in 155 colonic anastomoses performed on rats. The irradiation (external or endoscopical) ofthe anastomoses by repeated doses below 4 J/cm 2 suggest (1) the laser-induced enhancement of anastomotic healing can be obtained in both healthy colons or in situations in which anastomotic breakdown is mor…
What influence patients'choice for peritoneal dialysis? a qualitative study
2018
L’objectif de cette étude était d’identifier les facteurs qui influencent le choix de la dialyse péritonéale (DP) chez les patients insuffisants rénaux, dans un centre de dialyse en France offrant un dispositif d’éducation thérapeutique du patient (ETP) aux patients en pré-dialyse. Pour ce faire, nous avons mené trente six entretiens semi-directifs avec des patients, des médecins de l’équipe d’ETP et un cadre de santé. Nous avons également observé dix séances d’ETP afin d’explorer la nature des interactions entre les patients, leurs accompagnants et l’équipe soignante. Nos résultats révèlent que les facteurs qui poussent les patients à choisir la DP sont l’influence des proches, les préfére…
New intraocular lens for achromatizing the human eye.
2007
To describe the design of a new intraocular lens (IOL) capable of correcting spherical and chromatic aberrations when implanted in the human eye.University of Murcia, Murcia, and University of Valencia, Valencia, Spain.A hybrid singlet achromatic IOL was designed. The IOL has a combination of a refractive and a diffractive surface, with 1 of the surfaces being aspherical. Optical simulations were used to model the polychromatic modulation transfer function (MTF) in pseudophakic eyes to explain the differences in optical quality afforded by the achromatic IOL. Parameters such as focus shift, optical path difference, through-focus, and robustness to tilt and decentering of achromatic IOLs wer…
Correction: One-pot synthesis of a new generation of hybrid bisphosphonate polyoxometalate gold nanoparticles as antibiofilm agents
2019
A reduced polyoxovanadate functionalized with bisphosphonate molecules was synthesized and used to prepare in one step hybrid organic–inorganic polyoxometalate decorated gold nanoparticles. These new composites were shown to strongly inhibit P. aeruginosa and S. epidermidis biofilm growth, with the three components constituting the nanoparticles (Au0 core, vanadium and alendronate) acting synergistically.
Melting point, molecular symmetry and aggregation of tetrachlorobenzene isomers: the role of halogen bonding
2018
Tetrachlorobenzenes represent one of the best known, but not yet fully understood, group of isomers of the structure–melting point relationship. The differences in melting temperatures of these structurally related compounds were rationalized in terms of the hierarchy and nature of formed noncovalent interactions, and the molecular aggregation that is influenced by molecular symmetry. The highest melting point is associated with the highly symmetric 1,2,4,5-tetrachlorobenzene isomer. The structures of less symmetrical 1,2,3,4-tetrachlorobenzene and 1,2,3,5-tetrachlorobenzene, determined at 270 and 90 K, show a distinct pattern of halogen bonds, characterized by the different numbers and typ…