keyword
MENU ▼
Read by QxMD icon Read
search

Corneal Biomechanics

keyword
https://www.readbyqxmd.com/read/29032414/influence-of-lasek-on-schi%C3%A3-tz-goldmann-and-dynamic-contour-tonometry
#1
Marco Sales-Sanz, Esther Arranz-Marquez, Carolina Arruabarrena, Miguel A Teus
PURPOSE: Our purpose was to assess the effect of LASEK surgery on ocular rigidity and to compare its effect on intraocular pressure (IOP) readings with Goldmann applanation tonometry (GAT), Schiøtz indentation tonometry (ST) and dynamic contour tonometry (DCT). METHODS: Prospective, observational, single-masked cohort study. One eye per patient from 31 consecutive subjects who underwent LASEK refractive surgery to correct myopia, as well as from 108 non-operated myopic patients, were included...
October 14, 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
https://www.readbyqxmd.com/read/29032108/pregnancy-induced-changes-in-corneal-biomechanics-and-topography-are-thyroid-hormone-related
#2
David Tabibian, Begoña M de Tejada, Zisis Gatzioufas, Sabine Kling, Vanessa S Meiss, Marc-Olivier Boldi, Véronique Othenin-Girard, Antonina Chilin, Julien Lambiel, Florence Hoogewoud, Farhad Hafezi
PURPOSE: To identify biomechanical and topographical changes of the cornea during pregnancy and the postpartum period and its association to hormonal changes. DESIGN: Prospective single-center observational cohort study. METHODS: Participants: 24 pregnant women (48 eyes), monitored throughout pregnancy and after delivery. Biomechanical and topographical corneal properties were measured using the Ocular Response Analyzer (ORA) and a Scheimpflug imaging system (Pentacam HR) each trimester and 1 month after delivery...
October 12, 2017: American Journal of Ophthalmology
https://www.readbyqxmd.com/read/28991852/preparation-and-biomechanical-properties-of-an-acellular-porcine-corneal-stroma
#3
Qing Li, Hongmei Wang, Zhenye Dai, Yichen Cao, Chuanyu Jin
PURPOSE: To construct an acellular porcine corneal stroma (aPCS) as a human corneal stroma alternative and to further explore its biomechanical properties. METHODS: A combination of DNA-RNA enzymes and ultrasound technology was used to strip the native porcine corneal cells. The microstructure of aPCS was observed by H&E staining, DAPI staining, and α-Gal tests. The mechanical properties were detected by a tension machine. Cytotoxicity of aPCS was measured by the MTT assay...
November 2017: Cornea
https://www.readbyqxmd.com/read/28991620/new-perspectives-on-the-detection-and-progression-of-keratoconus
#4
REVIEW
Antonio Martínez-Abad, David P Piñero
Laser refractive surgery has increased markedly in recent years, making the detection of corneal abnormalities extremely relevant. For this reason, an accurate diagnosis of clinical or subclinical keratoconus is critical. Corneal topography is the primary diagnostic tool for keratoconus detection, and pachymetry data and corneal aberrations are also commonly used. Recently, tomographic measurements using optical coherence tomography and corneal biomechanical indices have been used. In incipient and subclinical keratoconus, the use of a single parameter as a diagnostic factor is not sufficiently accurate...
September 2017: Journal of Cataract and Refractive Surgery
https://www.readbyqxmd.com/read/28980563/-changes-in-biomechanical-properties-of-the-ocular-fibrous-tunic-in-patients-with-primary-open-angle-glaucoma-in-response-to-drug-induced-stress-relief-tests
#5
N V Makashova, A E Vasilyeva
AIM: To determine the effect of drug-induced stress-relief tests on biomechanical properties of the ocular fibrous tunic in eyes with early, moderate, or advanced primary open-angle glaucoma (POAG). MATERIAL AND METHODS: A total of 202 eyes of 150 patients with POAG of different severity (early, moderate, or advanced) and 36 eyes of 30 healthy controls were examined. The mean patient age was 62±8.2 years. All groups were standardized by age, sex, and the range of corneal-compensated intraocular pressure (IOP) at baseline (21-30 mmHg)...
2017: Vestnik Oftalmologii
https://www.readbyqxmd.com/read/28979996/impact-of-myopia-on-corneal-biomechanics-in-glaucoma-and-nonglaucoma-patients
#6
Sunee Chansangpetch, Rawiphan Panpruk, Anita Manassakorn, Visanee Tantisevi, Prin Rojanapongpun, Cameron P Hurst, Shan C Lin
Purpose: We evaluated the impact of myopia on corneal biomechanical properties in primary open-angle glaucoma (POAG) and nonglaucoma patients, and the effect of modification of glaucoma on myopic eyes. Methods: This cross-sectional study included 66 POAG eyes (33 myopia, 33 nonmyopia) and 66 normal eyes (33 myopia, 33 nonmyopia). Seven corneal biomechanical parameters were measured by ultra-high-speed Scheimpflug imaging, including corneal deformation amplitude (CDA), inward/outward corneal applanation length (ICA, OCA), inward/outward corneal velocity (ICV, OCV), radius, and peak distance (PD)...
October 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28945645/corneal-biomechanical-parameters-with-corneoscleral-contact-lenses-in-post-laser-in-situ-keratomileusis-eyes
#7
Juan C Montalt, Esteban Porcar, Enrique España-Gregori, Cristina Peris-Martínez
OBJECTIVE: To evaluate corneal biomechanical parameters wearing corneoscleral contact lenses (CScL) in patients with irregular corneas after laser in situ keratomileusis (LASIK). METHODS: Data from patients fitted with CScL because of corneal surface irregularities after complicated LASIK surgery were selected by two eye clinics. Previously and after 1 year of CScL fitting, corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), and central corneal thickness were evaluated...
September 21, 2017: Eye & Contact Lens
https://www.readbyqxmd.com/read/28944205/clinical-outcomes-of-small-incision-lenticule-extraction-versus-femtosecond-laser-assisted-lasik-for-myopia-a-meta-analysis
#8
Huan Yan, Li-Yan Gong, Wei Huang, Yan-Li Peng
AIM: To evaluate the possible differences in visual quality between small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK) for myopia. METHODS: A Meta-analysis was performed. Patients were from previously reported comparative studies treated with SMILE versus FS-LASIK. The PubMed, EMBASE, Cochrane, Web of Science and Chinese databases (i.e. WANFANG and CNKI) were searched in Nov. of 2016 using RevMan 5.1 version software...
2017: International Journal of Ophthalmology
https://www.readbyqxmd.com/read/28932338/recent-innovations-in-collagen-corneal-cross-linking-a-mini-review
#9
Iraklis Vastardis, Brigitte Pajic-Eggspuehler, Charis Nichorlis, Jörg Mueller, Bojan Pajic
BACKGROUND: The introduction of corneal cross-linking (CXL) with ultraviolet-A (UVA) and Riboflavin photosensitizer (Vit B2) from Seiler et al., revolutionized the treatment of Keratoconus and other corneal ectatic diseases. Today, the commonly known epithelium off Dresden protocol is in clinical use for the last 15 years with great success and regarded by many as the golden standard. METHODS: With several studies demonstrating its simplicity, efficacy and safety this revolutionary method, paved the way for new therapies and strategies in the treatment of corneal ectatic diseases and changed our understanding in corneal biomechanics...
2017: Open Ophthalmology Journal
https://www.readbyqxmd.com/read/28932334/corneal-biomechanics-in-ectatic-diseases-refractive-surgery-implications
#10
Renato Ambrósio, Fernando Faria Correia, Bernardo Lopes, Marcella Q Salomão, Allan Luz, Daniel G Dawson, Ahmed Elsheikh, Riccardo Vinciguerra, Paolo Vinciguerra, Cynthia J Roberts
BACKGROUND: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. METHOD: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant...
2017: Open Ophthalmology Journal
https://www.readbyqxmd.com/read/28924444/implantation-of-a-multifocal-toric-intraocular-lens-after-radial-keratotomy-and-cross-linking-with-hyperopia-and-astigmatism-residues-a-case-report
#11
Raffaele Nuzzi, Francesca Monteu, Federico Tridico
Radial keratotomy is a refractive surgical technique, widely used in the 80s and early 90s to correct myopia and astigmatism, but now overcome by more recent laser techniques. Important consequences, often in patients with more than 45 years of age, are progressive hyperopic shift and/or an increase in corneal astigmatism, whose main cause seems to be an increase in the curvature radius of the central portion of the cornea. This seems to be due to radial keratotomy incisions - with the consequent need for cross-linking - intraocular pressure, and corneal biomechanical parameters...
May 2017: Case Reports in Ophthalmology
https://www.readbyqxmd.com/read/28913507/keratoconus-diagnosis-using-corvis-st-measured-biomechanical-parameters
#12
Roghiyeh Elham, Ebrahim Jafarzadehpur, Hassan Hashemi, Kazem Amanzadeh, Fereshteh Shokrollahzadeh, Abbasali Yekta, Mehdi Khabazkhoob
PURPOSE: To assess the diagnostic power of the Corneal Visualization Scheimpflug Technology (Corvis ST) provided corneal biomechanical parameters in keratoconic corneas. METHODS: The following biomechanical parameters of 48 keratoconic eyes were compared with the corresponding ones in 50 normal eyes: time of the first applanation and time from start to the second applanation [applanation-1 time (A1T) and applanation-2 time (A2T)], time of the highest corneal displacement [highest concavity time (HCT)], magnitude of the displacement [highest concavity deformation amplitude (HCDA)], the length of the flattened segment in the applanations [first applanation length (A1L) and second applanation length (A2L)], velocity of corneal movement during applanations [applanation-1 velocity (A1V) and applanation-2 velocity (A2V)], distance between bending points of the cornea at the highest concavity [highest concavity peak distance (HCPD)], central concave curvature at the highest concavity [highest concavity radius (HCR)]...
September 2017: Journal of Current Ophthalmology
https://www.readbyqxmd.com/read/28891725/age-related-change-in-corneal-biomechanical-parameters-in-a-healthy-caucasian-population
#13
Ali Riza Cenk Celebi, Ayse Ebru Kilavuzoglu, Ugur Emrah Altiparmak, C Banu Cosar Yurteri
PURPOSE: To determine the effect of aging on corneal biomechanical parameters measured via ocular response analyzer in a homogenous healthy Caucasian population. METHODS: A total of 2039 Caucasian adults were consecutively recruited and divided into seven groups according to decades of age. The difference in mean corneal hysteresis (CH), mean corneal resistance factor (CRF), mean Goldmann-correlated intraocular pressure (IOPg), and mean corneal-compensated IOP (IOPcc) between decades of age were investigated...
September 11, 2017: Ophthalmic Epidemiology
https://www.readbyqxmd.com/read/28880339/comparison-of-corneal-dynamic-and-tomographic-analysis-in-normal-forme-fruste-keratoconic-and-keratoconic-eyes
#14
Yu Meng Wang, Tommy C Y Chan, Marco Yu, Vishal Jhanji
PURPOSE: To investigate and compare the diagnostic ability of corneal tomography and dynamic corneal response to differentiate between normal eyes and those with forme fruste keratoconus and keratoconus. METHODS: Corneal tomography was performed using Pentacam (Pentacam HR; Oculus Optikgeräte, Wetzlar, Germany). Corneal deformation response was captured via Corvis ST (Optikgeräte) using a beta version of Corvis software. Classification analysis between normal eyes and eyes with forme fruste keratoconus and between normal and keratoconic eyes was evaluated using receiver operating characteristic curves...
September 1, 2017: Journal of Refractive Surgery
https://www.readbyqxmd.com/read/28880338/comparison-of-corneal-deformation-parameters-in-keratoconic-and-normal-eyes-using-a-non-contact-tonometer-with-a-dynamic-ultra-high-speed-scheimpflug-camera
#15
Ryan N Mercer, George O Waring, Cynthia J Roberts, Vishal Jhanji, Yumeng Wang, Joao S Filho, Richard A Hemings, Karolinne M Rocha
PURPOSE: To evaluate and compare biomechanical properties in normal and keratoconic eyes using a dynamic ultra-high-speed Scheimpflug camera equipped with a non-contact tonometer (Corvis ST; Oculus Optikgeräte GmbH, Wetzlar, Germany). METHODS: This retrospective study evaluated 89 eyes (47 normal, 42 keratoconic) and a validation arm of 72 eyes (33 normal, 39 keratoconic) using the Corvis ST. A diagnosis of keratoconus was established by clinical findings confirmed by topography and tomography...
September 1, 2017: Journal of Refractive Surgery
https://www.readbyqxmd.com/read/28864177/corneoscleral-stiffening-increases-iop-spike-magnitudes-during-rapid-microvolumetric-change-in-the-eye
#16
Keyton Clayson, Xueliang Pan, Elias Pavlatos, Ryan Short, Hugh Morris, Richard T Hart, Jun Liu
Factors governing the steady-state IOP have been extensively studied; however, the dynamic aspects of IOP are less understood. Clinical studies have suggested that intraocular pressure (IOP) fluctuation may be associated with glaucoma risk. This study aims to investigate how stiffening of corneoscleral biomechanical properties affects IOP spikes induced by rapid microvolumetric change. Porcine eyes (n = 25 in total) were subjected to volumetric infusions before and after external treatment of a circular area (11 mm diameter) in either the central cornea or posterior sclera...
August 30, 2017: Experimental Eye Research
https://www.readbyqxmd.com/read/28858155/in-vivo-non-invasive-measurement-of-young-s-modulus-of-elasticity-in-human-eyes-a-feasibility-study
#17
Arthur J Sit, Shuai-Chun Lin, Arash Kazemi, Jay W McLaren, Christopher M Pruet, Xiaoming Zhang
PURPOSE: Abnormal ocular biomechanical properties may be important for understanding the risk of glaucoma. However, there are no clinical methods for measuring standard material properties in patients. In this feasibility study we demonstrated proof-of-principle for a novel method, ultrasound surface wave elastography (USWE), to determine the in vivo Young's modulus of elasticity of corneas in normal human eyes. METHODS: Twenty eyes of 10 healthy subjects (mean age 51...
August 28, 2017: Journal of Glaucoma
https://www.readbyqxmd.com/read/28855517/cross-linked-decellularized-porcine-corneal-graft-for-treating-fungal-keratitis
#18
Yongliang Lin, Qinxiang Zheng, Shanshan Hua, Yongchun Meng, Wei Chen, Yifei Wang
This study aims to develop a cross-linked decellularized porcine corneal graft (cDPC) as a substitute for lamellar donor corneas and to evaluate the feasibility of using cDPC to treat fungal keratitis. The cDPC was prepared by decellularization, chemical crosslinking and γ-ray irradiation. Transparency, effectiveness of decellularization and biomechanical strength of cDPC were evaluated. The safety and efficacy of using cDPC to treat fungal keratitis were evaluated in the rabbit model. The transparency of cDPC was similar to that of a native porcine cornea (NPC), and no intact cells were observed in cDPC except for an insignificant amount of residual shrinking cellular nucleus...
August 30, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28832734/corneal-properties-and-glaucoma-a-review-of-the-literature-and-meta-analysis
#19
REVIEW
Ricardo Gaspar, Luís Abegão Pinto, David Cordeiro Sousa
PURPOSE: Studies have suggested that corneal biomechanical properties influence intraocular pressure (IOP) measurements, namely central corneal thickness (CCT) and corneal hysteresis (CH). The present study aimed to investigate the associations of CH and CCT with glaucoma development. METHODS: We performed a review of the literature and meta-analysis of observational studies (2006-2016) that included both adult glaucoma patients and controls and reported CCT and CH as outcomes...
June 2017: Arquivos Brasileiros de Oftalmologia
https://www.readbyqxmd.com/read/28831080/dynamic-heterogeneous-endothelial-tie2-expression-and-capillary-blood-flow-during-microvascular-remodeling
#20
Molly R Kelly-Goss, Bo Ning, Anthony C Bruce, Daniel N Tavakol, David Yi, Song Hu, Paul A Yates, Shayn M Peirce
Microvascular endothelial cell heterogeneity and its relationship to hemodynamics remains poorly understood due to a lack of sufficient methods to examine these parameters in vivo at high resolution throughout an angiogenic network. The availability of surrogate markers for functional vascular proteins, such as green fluorescent protein, enables expression in individual cells to be followed over time using confocal microscopy, while photoacoustic microscopy enables dynamic measurement of blood flow across the network with capillary-level resolution...
August 22, 2017: Scientific Reports
keyword
keyword
32442
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"