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https://www.readbyqxmd.com/read/28089285/thick-keratoconic-cornea-associated-with-posterior-polymorphous-corneal-dystrophy
#1
K Zaarour, E Slim, J Antoun, N Waked
INTRODUCTION: We herein report a case of bilateral unusually thick non-edematous keratoconic corneas with associated endothelial features of posterior polymorphous corneal dystrophy (PPCD). CASE REPORT: We report the case of a 27-year-old myopic woman who presented for refractive surgery. Slit lamp exam showed bilateral corneal protrusion with diffuse deep stromal and endothelial vesicular opacities and small paracentral bands. Topography showed generalized advanced corneal steepening in both eyes with increased anterior and posterior central corneal elevations in comparison to the best fit sphere...
January 12, 2017: Journal Français D'ophtalmologie
https://www.readbyqxmd.com/read/28060145/corneal-endothelial-cell-density-and-morphology-in-different-trimesters-of-pregnancy
#2
Nurgül Örnek, Zeynep Özcan Dağ, Kemal Örnek
OBJECTIVES: To evaluate corneal endothelial cell density (CD) and morphology in different trimesters of pregnancy. METHODS: This prospective study included 66 (66 eyes) pregnant women. The patient group was divided into three subgroups comprised of 22 women in the first, second, and third trimesters of pregnancy. An age-matched group of 22 (22 eyes) volunteers served as controls. Corneal measurements were performed using specular microscopy (Noncon Robo SP8000, Konan Medical)...
January 4, 2017: Eye & Contact Lens
https://www.readbyqxmd.com/read/28060074/eventual-endothelial-failure-after-initial-corneal-clearing-after-a-detached-endothelial-graft-in-fuchs-dystrophy
#3
Hyunjoo J Lee, Wuqaas M Munir
PURPOSE: To report a case of eventual corneal endothelial cell failure after spontaneous resolution of corneal edema after failed Descemet membrane endothelial keratoplasty (DMEK). METHODS: Retrospective case report. RESULTS: A 56-year-old man with Fuchs endothelial corneal dystrophy underwent cataract and DMEK surgery in the left eye. The transplanted DMEK graft detached in the early postoperative period and formed a peripheral scroll. Despite graft detachment, corneal edema resolved with endothelial cell repopulation of the central cornea...
February 2017: Cornea
https://www.readbyqxmd.com/read/28060070/enhancing-dmek-success-by-identifying-optimal-levels-of-trypan-blue-dye-application-to-donor-corneal-tissue
#4
Parag A Majmudar, Lauren Johnson
PURPOSE: The purpose of this study was to determine the correct concentration and duration of application of trypan blue dye to Descemet membrane endothelial keratoplasty (DMEK) donor corneal tissue before transplant to enhance visibility while minimizing damage to the tissue. METHODS: Corneas were precut for DMEK using an 8-mm punch, and each was stained with either 0.06% or 0.15% trypan blue for a duration of 1, 3, or 5 minutes. After staining, each tissue was placed in balanced salt solution and observed to determine how quickly the stain faded from the tissue using a grading system...
February 2017: Cornea
https://www.readbyqxmd.com/read/28060061/conventional-and-iontophoresis-corneal-cross-linking-for-keratoconus-efficacy-and-assessment-by-optical-coherence-tomography-and-confocal-microscopy
#5
Léa Jouve, Vincent Borderie, Otman Sandali, Cyrille Temstet, Elena Basli, Laurent Laroche, Nacim Bouheraoua
PURPOSE: To compare the efficacy, safety, and microstructural corneal changes during 2 years after conventional corneal collagen cross-linking (C-CXL) and transepithelial corneal CXL by iontophoresis (I-CXL) for keratoconus. METHODS: Eighty eyes of 80 patients with progressive keratoconus were treated by C-CXL (n = 40) or I-CXL (n = 40). Patients were investigated before surgery and 1, 3, 6, 12, and 24 months after treatment. We measured central corneal thickness and maximal simulated keratometry values (Kmax) and performed specular microscopy and in vivo confocal microscopy at each time point...
February 2017: Cornea
https://www.readbyqxmd.com/read/28050968/simulation-of-scintillation-light-output-in-lyso-scintillators-through-a-full-factorial-design
#6
Francis Loignon-Houle, Mélanie Bergeron, Catherine M Pepin, Serge A Charlebois, Roger Lecomte
Individually coupled scintillation detectors used in positron emission tomography (PET) imaging suffer from important signal losses due to the suboptimal light collection from crystals. As only a fraction of the light is generally extracted from long and thin scintillators, it is important to identify and understand the predominant causes of signal loss in order to eventually recover it. This simulation study investigates the multiple factors affecting the light transport in high-aspect ratio LYSO scintillators wrapped in specular reflectors through a full factorial design...
January 4, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28025053/lightness-perception-for-matte-and-glossy-complex-shapes
#7
Matteo Toscani, Matteo Valsecchi, Karl R Gegenfurtner
Humans are able to estimate the reflective properties of the surface (albedo) of an object despite the large variability in the reflected light due to shading, illumination and specular reflection. Here we first used a physically based rendering simulation to study how different statistics (i.e. percentiles) based on the luminance distributions of matte and glossy objects predict the overall surface albedo. We found that the brightest parts of matte surfaces are good predictors of the surface albedo. As expected, the brightest parts led to poor performance in glossy surfaces...
January 13, 2017: Vision Research
https://www.readbyqxmd.com/read/28024571/ocular-biocompatibility-of-gelatin-microcarriers-functionalized-with-oxidized-hyaluronic-acid
#8
Jui-Yang Lai, David Hui-Kang Ma
Given that the presence of aldehyde groups on the oxidized sugar residues may pose toxicity concerns, it is necessary to examine the safety of gelatin microcarriers (GMC) functionalized with oxidized hyaluronic acid (oHA) for potential ophthalmic applications. In this study, the ocular biocompatibility of biopolymer microcarriers was investigated in vitro using primary rabbit corneal cell cultures and in vivo using the anterior chamber of the rabbit eye model. Our results showed that different types of corneal cells including epithelial, stromal, and endothelial cells remain viable and actively proliferate following 2 and 4days of exposure to test materials...
March 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28024255/dual-route-imitation-in-preschool-children
#9
Linda Sebastianutto, Paola Mengotti, Caterina Spiezio, Raffaella Ida Rumiati, Evan Balaban
Imitation can be realized via two different routes: a direct route that translates visual input into motor output when gestures are meaningless or unknown, and a semantic route for known/meaningful gestures. Young infants show imitative behaviours compatible with the direct route, but little is known about the development of the semantic route, studied here for the first time. The present study examined preschool children (3-5years of age) imitating gestures that could be transitive or intransitive, and meaningful or meaningless...
December 23, 2016: Acta Psychologica
https://www.readbyqxmd.com/read/28009792/clinical-features-in-children-with-posterior-polymorphous-corneal-dystrophy
#10
Ye Jin Ahn, Soon Il Choi, Hae Ri Yum, Sun Young Shin, Shin Hae Park
PURPOSE: To describe clinical features in children diagnosed with posterior polymorphous corneal dystrophy (PPCD) in their first or second decade of life. METHODS: A retrospective study was performed with the medical records of seven unrelated Korean pediatric patients who were diagnosed with PPCD and were followed up for a minimum of 3 years. Thorough ocular examinations were performed, including best-corrected visual acuity, intraocular pressure, refractive and keratometric measurements, slit-lamp biomicroscopy, and specular microscopy at all visits...
December 22, 2016: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/28003782/corneal-endothelial-cell-density-in-healthy-caucasian-population
#11
Rahmi Duman, Mediha Tok Çevik, Sadık Görkem Çevik, Reşat Duman, İrfan Perente
AIM: To reveal the changes of corneal endothelial characteristics with aging among Caucasian population. METHODS: Non-contact specular microscopy was performed in 564 eyes of 282 healthy Caucasian Turkish patients. Endothelial cell density (MCD), mean cell area (MCA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and central corneal thickness (CCT) were measured. RESULTS: The mean age was 42 ± 17.1 (6-85) years...
October 2016: Saudi Journal of Ophthalmology: Official Journal of the Saudi Ophthalmological Society
https://www.readbyqxmd.com/read/27998103/nb2o5-nanostructure-evolution-on-nb-surfaces-via-low-energy-he-ion-irradiation
#12
Theodore Joseph Novakowski, Jitendra Kumar Tripathi, Ahmed Hassanein
We propose low-energy, broad-beam He(+) ion irradiation as a novel processing technique for the generation of Nb2O5 surface nanostructures due to its relative simplicity and scalability in a commercial setting. Since there have been relatively few studies involving the interaction of high-fluence, low-energy He(+) ion irradiation and Nb (or its oxidized states), this systematic study explores both effects of fluence and sample temperature during irradiation on resulting surface morphology. Detailed normal and cross-sectional scanning electron microscopy (SEM) studies reveal subsurface He bubble formation and elucidate potential driving mechanisms for nanostructure evolution...
December 21, 2016: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/27991635/mesoscale-simulation-of-phoretically-osmotic-boundary-conditions
#13
Mingcheng Yang, Riu Liu, Fangfu Ye, Ke Chen
Boundary walls can drive the tangential flow of fluids by phoretic osmosis when exposed to a gradient field, including chemical, thermal or electric potential gradient. At the microscale, such boundary driving mechanisms become quite pronounced. Here, we propose a mesoscale strategy to simulate the phoretically osmotic boundaries, in which the microscopic fluid-wall interactions are coarse-grained into the bounce-back or specular reflection, and the phoretically osmotic force is generated by selectively reversing the tangential velocity of specific fluid particles near the boundary wall...
January 18, 2017: Soft Matter
https://www.readbyqxmd.com/read/27986387/an-observational-cross-sectional-study-on-the-corneal-endothelium-of-medium-term-rigid-gas-permeable-contact-lens-wearers
#14
Michael J Doughty
PURPOSE: To assess if polymegethism and pleomorphism were evident in corneal endothelium after medium-term rigid gas permeable (RGP) contact lens wear. METHODS: In a cross-sectional observational study over 12 years, single images of the central region of the corneal endothelium of one eye of 46 subjects were taken with a non-contact specular microscope, along with a measure of central corneal thickness (CCT). The images were printed onto A3-sized paper and 100 cells/image measured by planimetry...
December 13, 2016: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
https://www.readbyqxmd.com/read/27984505/relationship-between-corneal-thickness-and-radius-to-body-height
#15
Sven Jonuscheit, Michael J Doughty, Raúl Martín, Ana Rio-Cristobal
PURPOSE: To investigate the possible association between body stature (height) and corneal thickness and radius in younger-adult Caucasians, especially within the context of previously published literature. METHODS: Body height and weight were measured in 109 healthy subjects, with an average age of 24 ± 6 years (mean ± SD). Subjects underwent an ophthalmic assessment including anterior segment imaging by Scheimpflug topography and specular microscopy. Central and peripheral corneal thickness and corneal radius were analyzed...
December 15, 2016: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/27982210/comparison-of-central-corneal-thickness-estimated-by-an-ultrasonic-pachymeter-and-non-contact-specular-microscopy
#16
Sadık Görkem Çevik, Rahmi Duman, Mediha Tok Çevik, Sertaç Argun Kıvanç, Berna Akova-Budak, Irfan Perente, Resat Duman
Purpose: To compare central corneal thickness (CCT) measurements of healthy individuals obtained with ultrasonic pachymetry (UP) and non-contact specular microscopy (NCSM). Method: In total, 148 eyes of 74 subjects with no ocular or systemic diseases were included in the study. Central corneal thickness measurements of all patients performed with UP and NCCM were compared. Results: A total of 74 subjects (38 females) were included in this study...
September 2016: Arquivos Brasileiros de Oftalmologia
https://www.readbyqxmd.com/read/27980360/changes-in-corneal-endothelial-cell-after-ahmed-glaucoma-valve-implantation-and-trabeculectomy-1-year-follow-up
#17
Min Su Kim, Kyoung Nam Kim, Chang-Sik Kim
PURPOSE: To compare changes in corneal endothelial cell density (CECD) after Ahmed glaucoma valve (AGV) implantation and trabeculectomy. METHODS: Changes in corneal endothelium in patients that underwent AGV implantation or trabeculectomy were prospectively evaluated. Corneal specular microscopy was performed at the central cornea using a non-contact specular microscope before surgery and 6 months and 12 months after surgery. The CECD, hexagonality of the endothelial cells, and the coefficient of variation of the cell areas were compared between the two groups...
December 2016: Korean Journal of Ophthalmology: KJO
https://www.readbyqxmd.com/read/27977477/iridocorneal-endothelial-syndrome-presenting-with-large-diurnal-intraocular-pressure-fluctuation
#18
Rachel S Mogil, Jung Min Lee, Andrew Tirsi, Celso Tello, Sung Chul Park
PURPOSE OF THE STUDY: The purpose of the study was to report a case of iridocorneal endothelial syndrome with an initial presentation of a large diurnal fluctuation of intraocular pressure (IOP) which peaked early in the morning. METHODS: A 31-year-old white man had transient blurry vision oculus sinister (OS) upon awakening in the morning for the past 2 months. The blurry vision improved within 1 to 2 hours. Clinical examination, diurnal IOP measurements, and specular microscopy were performed to investigate the cause of his transient blurry vision...
December 13, 2016: Journal of Glaucoma
https://www.readbyqxmd.com/read/27965261/very-early-endothelial-cell-loss-after-penetrating-keratoplasty-with-organ-cultured-corneas
#19
Anne Sophie Gauthier, Thibaud Garcin, Gilles Thuret, Zhiguo He, Remy Jullienne, Marie Caroline Trone, Chaker Nefzaoui, Sophie Acquart, Fabien Forest, Michel Péoc'h, Bernard Delbosc, Philippe Gain
AIMS: After keratoplasty, postoperative endothelial cell loss is calculated between the eye bank endothelial cell density (ebECD) and the postoperative specular microscopy (SM). To elucidate the very early cell loss, always described after penetrating keratoplasty (PK), we designed two complementary studies. METHODS: (1) Clinical prospective study of 90 consecutive PKs (keratoconus, Fuchs' corneal dystrophy, lattice dystrophy, bullous keratopathy) with organ-cultured corneas and postoperative follow-up by SM at day 5 (D5), D15, month 1 (M1) and M3...
December 13, 2016: British Journal of Ophthalmology
https://www.readbyqxmd.com/read/27959811/indoor-scene-reconstruction-using-near-light-photometric-stereo
#20
Jingtang Liao, Bert Buchholz, Jean-Marc Thiery, Pablo Bauszat, Elmar Eisemann
We propose a novel framework for photometric stereo (PS) under low-light conditions using uncalibrated nearlight illumination. It operates on free-form video sequences captured with a minimalistic and affordable setup. We address issues such as albedo variations, shadowing, perspective projections and camera noise. Our method uses specular spheres detected with a perspective-correcting Hough transform to robustly triangulate light positions in the presence of outliers via a least-squares approach. Furthermore, we propose an iterative reweighting scheme in combination with an `p-norm minimizer to robustly solve the calibrated near-light PS problem...
December 7, 2016: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
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