1. Articles in category: Ophthalmology

    577-600 of 10399 « 1 2 ... 22 23 24 25 26 27 28 ... 432 433 434 »
    1. AMD Classification in Choroidal OCT Using Hierarchical Texton Mining

      AMD Classification in Choroidal OCT Using Hierarchical Texton Mining

      In this paper, we propose a multi-step textural feature extraction and classification method, which utilizes the feature learning ability of Convolutional Neural Networks (CNN) to extract a set of low level primitive filter kernels, extracts spatial information using clustering and Local Binary Patterns (LBP) and then generalizes the discriminative power by forming a histogram based descriptor. It integrates the concept of hierarchical texton mining and data driven kernel learning into a uniform framework. The proposed method is applied to a practical medical diagnosis problem of classifying different stages of Age-Related Macular Degeneration (AMD) using a dataset comprising long-wavelength Optical Coherence ...

      Read Full Article
    2. Role of anterior segment optical coherence tomography in angle closure disease: a review

      Role of anterior segment optical coherence tomography in angle closure disease: a review

      This article aims to review the published literature pertaining to the use of anterior segment optical coherence tomography (AS-OCT) in the evaluation of angle closure disease. Searches on the available published literature were last conducted on June 15, 2017. Rated as Level I evidence, we found that AS-OCT has shown good sensitivity and moderate diagnostic accuracy to detect narrow angles when compared with gonioscopy. AS-OCT quantitative and qualitative parameters demonstrated strong association with the presence of gonioscopically closed-angles. This technology provides an objective non-contact method of assessing the angle that is well tolerated by the patient and correlates well with ...

      Read Full Article
    3. Optical Coherence Tomography Angiography Examinations in Chronic Retinal Artery Occlusion (RAO-OCTA)

      Optical Coherence Tomography Angiography Examinations in Chronic Retinal Artery Occlusion (RAO-OCTA)

      Occlusion of the retinal arteries is an emergency which causes sudden, painless unilateral vision loss. Loss of blood flow causes ischemic damage to the retina. The extent of damage depends on the area affected. Following the acute phase of the disease re-canalization occurs and lesser blood flow can be detected usually without functional recovery. Purpose of the study is to examine the retinal blood flow in chronic cases of retinal artery occlusion. Standard procedures to examine this disease include retinoscopy following pupil dilation, fluorescein angiography and more recently, optical coherence tomography (OCT). The latest direction in OCT development was OCT ...

      Read Full Article
    4. Complex signal-based optical coherence tomography angiography enables in vivo visualization of choriocapillaris in human choroid

      Complex signal-based optical coherence tomography angiography enables in vivo visualization of choriocapillaris in human choroid

      The choriocapillaris (CC) plays an essential role in maintaining the normal functions of the human eye. There is increasing interest in the community to develop an imaging technique for visualizing the CC, yet this remains underexplored due to technical limitations. We propose an approach for the visualization of the CC in humans via a complex signal-based optical microangiography (OMAG) algorithm, based on commercially available spectral domain optical coherence tomography (SD-OCT). We show that the complex signal-based OMAG was superior to both the phase and amplitude signal-based approaches in detailing the vascular lobules previously seen with histological analysis. With this improved ...

      Read Full Article
    5. Optical coherence tomography changes following vitrectomy for long standing premacular hemorrhage in Valsalva retinopathy

      Optical coherence tomography changes following vitrectomy for long standing premacular hemorrhage in Valsalva retinopathy

      Dear Editor, Premacular hemorrhage is a common cause of sudden profound visual loss in otherwise healthy eye. One of the commonest causes of premacular hemorrhage in clinical practice is Valsalva retinopathy, which was first described by Thomas Duane in 1972 [1] . In the setting of Valsalva retinopathy these hemorrhages are a result of ruptured perifoveal capillaries because of raised intravenous pressure of the eye. This happens when the raised intra-thoracic pressure due to Valsalva maneuver is transmitted to the ocular venous system because of valve-less nature of the later. While the exact location of these hemorrhages has been disputed, they ...

      Read Full Article
    6. Agreement of swept-source and spectral-domain optical coherence-tomography retinal thickness measurements in neovascular age-related macular degeneration

      Agreement of swept-source and spectral-domain optical coherence-tomography retinal thickness measurements in neovascular age-related macular degeneration

      Changes in macular thickness measurements in neovascular age-related macular degeneration (nAMD) are thought to reflect disease activity, and can be used to guide treatment with antiangiogenic agents. 1 Both spectral-domain optical coherence tomography (SD-OCT) and the more recently introduced swept-source optical coherence tomography (SS-OCT) have onboard segmentation algorithms that deliver automated retinal thickness measurements. Agreement between OCT derived macular thickness measurements is critical for monitoring of patients if these modalities are to be used interchangeably. This prospective cross-sectional study sought to determine the limits of agreement between SD-OCT (Spectralis; Heidelberg Engineering) and SS-OCT (DRI OCT-1 Atlantis; Topcon Medical Systems) in ...

      Read Full Article
    7. The Recovery of Microvascular Status Evaluated by Optical Coherence Tomography Angiography in Patients after Successful Macular Hole Surgery

      The Recovery of Microvascular Status Evaluated by Optical Coherence Tomography Angiography in Patients after Successful Macular Hole Surgery

      Purpose: The aim of this study was to evaluate the optical coherence tomography angiography (OCTA) features of patients who underwent successful macular hole (MH) surgery. Methods: Nineteen patients who underwent surgery in a single eye due to MH and 13 healthy subjects as a control group were included in the study. Vascular densities, flow indexes, and the foveal avascular zone (FAZ) area in superficial and deep retinal capillary plexuses were evaluated by OCTA in the right eyes of the control group, and both the surgical and healthy fellow eyes of the patients. Results: The mean vascular densities of the superficial ...

      Read Full Article
    8. The temporal retinal nerve fiber layer thickness is the most important optical coherence tomography estimate in multiple sclerosis

      The temporal retinal nerve fiber layer thickness is the most important optical coherence tomography estimate in multiple sclerosis

      Background: Reduced peripapillary retinal nerve fiber layer (pRNFL) and combined ganglion cell and inner plexiform layer (GCIP) thicknesses as measured by optical coherence tomography (OCT) have been observed in MS patients. The purpose was to determine the most associative OCT measure to level of cognitive and physical disability in MS. Methods: Data was collected from 546 MS patients and 175 healthy controls (HCs). We compared the average peripapillary RNFL (pRNFL), temporal pRNFL (tRNFL), overall inner ganglion cell/inner plexiform layer (GCIP) and the overall ganglion cell complex (GCC) including macular RNFL and GCIP thicknesses measurements in differentiating MS subtypes from ...

      Read Full Article
    9. Digital scan of the eye provides accurate picture of a person’s general health

      Digital scan of the eye provides accurate picture of a person’s general health

      Personalized medicine or "precision medicine" is the most significant trend in 21st century medicine. "It’s all about the right treatment for the right patient at the right time," says Ursula Schmidt-Erfurth, Head of MedUni Vienna's Department of Ophthalmology and Optometry. And looking into the eye – using digital techniques and analysing Big Data – also provides an accurate picture of a person's general medical condition, facilitates early diagnosis and treatment and makes for transparent patients. The ART-2017 specialist conference (Advanced Retinal Therapy) is characterised by these digital developments in personalised medicine.

      Read Full Article
    10. Müller Glia Cell Activation in a Laser-induced Retinal Degeneration and Regeneration Model in Zebrafish

      Müller Glia Cell Activation in a Laser-induced Retinal Degeneration and Regeneration Model in Zebrafish

      A fascinating difference between teleost and mammals is the lifelong potential of the teleost retina for retinal neurogenesis and regeneration after severe damage. Investigating the regeneration pathways in zebrafish might bring new insights to develop innovative strategies for the treatment of retinal degenerative diseases in mammals. Herein, we focused on the induction of a focal lesion to the outer retina in adult zebrafish by means of a 532 nm diode laser. A localized injury allows investigating biological processes that take place during retinal degeneration and regeneration directly at the area of damage. Using non-invasive optical coherence tomography (OCT), we were ...

      Read Full Article
    11. Peripapillary Perfused Capillary Density in Exfoliation Syndrome and Exfoliation Glaucoma versus POAG and Healthy Controls: An OCTA Study

      Peripapillary Perfused Capillary Density in Exfoliation Syndrome and Exfoliation Glaucoma versus POAG and Healthy Controls: An OCTA Study

      PURPOSE: To compare the peripapillary perfused capillary density (PCD) among eyes with exfoliation syndrome (XFS), exfoliation glaucoma (XFG), primary open-angle glaucoma (POAG), and controls. DESIGN: Observational, cross-sectional study. METHODS: Optical coherence tomography angiography (OCTA) images (4.5×4.5 mm) of the optic nerve head were obtained using a commercial spectral domain OCTA system (AngioVue Avanti RTVue-XR, OptoVue, Fremont, CA). Two concentric circles with 1.95-mm (inner) and 3.45-mm (outer) diameters were placed manually, producing an annulus of width 0.75 mm centered at the optic disc. PCD was calculated as the ratio of pixels associated with capillaries to ...

      Read Full Article
    12. In Vivo Imaging of Cx3cr1gfp/gfp Reporter Mice with Spectral-domain Optical Coherence Tomography and Scanning Laser Ophthalmoscopy

      In Vivo Imaging of Cx3cr1gfp/gfp Reporter Mice with Spectral-domain Optical Coherence Tomography and Scanning Laser Ophthalmoscopy

      Spectral domain optical coherence tomography (SD-OCT) and scanning laser ophthalmoscopy (SLO) are extensively used in experimental ophthalmology. In the present protocol, mice expressing green fluorescent protein (gfp) under the promoter of Cx3cr1 (BALB/c-Cx3cr1 gfp/gfp ) were used to image microglia cells in vivo in the retina. Microglia are resident macrophages of the retina and have been implicated in several retinal diseases 1 , 2 , 3 , 4 , 5 , 6 . This protocol provides a detailed approach for generation of retinal B-scans, with SD-OCT, and imaging of microglia cell distribution in Cx3cr1 gfp/gfp mice with SLO in vivo, using an ophthalmic imaging ...

      Read Full Article
    13. Alphabet's Deepmind Is Trying to Transform Health Care — But Should an AI Company Have Your Health Records?

      Alphabet's Deepmind Is Trying to Transform Health Care — But Should an AI Company Have Your Health Records?

      DeepMind, the digital brain foundry owned by Google’s parent company, Alphabet, wants to use artificial intelligence to solve… well, everything. Last year, its software taught itself to play the strategy game Go better than any human on the planet. For its next trick, it wants to move beyond games to a very real-world problem: health care. The London company has a fast-growing division—now 100 strong—dedicated to health. And while DeepMind’s research on Go may be years away from yielding practical applications, its health-care work is affecting people’s lives today through projects with the U.K ...

      Read Full Article
    14. Surgical microscope with integrated optical coherence tomography and display systems

      Surgical microscope with integrated optical coherence tomography and display systems

      An ophthalmic surgical microscope includes a beam coupler positioned along an optical path of the surgical microscope between a first eyepiece and magnifying/focusing optics, the beam coupler operable to direct the OCT imaging beam along a first portion of the optical path of the surgical microscope between the beam coupler and a patient's eye (an OCT image being generated based on a reflected portion of the OCT imaging beam). The surgical microscope additionally includes a real-time data projection unit operable to project the OCT image generated by the OCT system and a beam splitter positioned along the optical ...

      Read Full Article
      Mentions: Lingfeng Yu
    15. Factors affecting foveal avascular zone in healthy eyes: An examination using swept-source optical coherence tomography angiography

      Factors affecting foveal avascular zone in healthy eyes: An examination using swept-source optical coherence tomography angiography

      Objective To examine factors affecting foveal avascular zone (FAZ) area in healthy eyes using swept-source optical coherence tomography angiography (OCTA). Methods This prospective, cross-sectional study included 144 eyes of 144 individuals (77 women, 67 men) with a best corrected visual acuity of at least 20/20 and no history of ocular disorders. The area of the superficial FAZ was assessed using OCTA. Age, gender, central retinal thickness (CRT), retinal vascular density, refractive error, and axial length were examined to determine associations with FAZ area. Results The mean age of the subjects was 42.1 ± 20.2 years (range: 10–79 ...

      Read Full Article
    16. A Radio Podcast from New Retina Radio on OCT and Anti-VEGF, A Biography

      A Radio Podcast from New Retina Radio on OCT and Anti-VEGF, A Biography

      The guidance of Anti-VEGF therapy using OCT is one of the major drivers of Ophthalmic OCT use benefiting millions of people worldwide facing age related macular degeneration.  This link is from New Retina Radio and continues its biography of anti-VEGF. John D. Pitcher III, MD, picks up the story where we left off: in a world where pegaptanib was the only intravitreal injection approved for treating wet AMD. But a deep dive into the literature and a few calculations on the back of a napkin are about to change retina practice forever. Guests in this episode include Bob Avery, MD ...

      Read Full Article
    17. Hypoxia challenge test and retinal circulation changes – a study using ocular coherence tomography angiography

      Hypoxia challenge test and retinal circulation changes – a study using ocular coherence tomography angiography

      Purpose Previous studies report that the response of retinal vessels to a decrease in oxygen (hypoxia) is vasodilation, thus increasing blood flow. We aimed to characterize the changes in retinal microvasculature induced by a mild hypoxia stress test in a healthy population, using ocular coherence tomography angiography (OCT-A) technology. Methods Interventional repeated-measures study. The standardized hypoxia challenge test (HCT) was performed to all volunteers, according to the British Thoracic Society protocol. Ocular coherence tomography angiography (OCT-A) was performed at three time-points (baseline, during HCT and 30′ posthypoxia). Macular and peripapillary vessel densities were assessed using the built-in software. To minimize ...

      Read Full Article
    18. Secondary glaucoma in uveitis: comparison of the optic nerve head morphology among a nonmydriatic fundus camera, HRT, and SD-OCT

      Secondary glaucoma in uveitis: comparison of the optic nerve head morphology among a nonmydriatic fundus camera, HRT, and SD-OCT

      To assess the correlation between the disc damage likelihood scale (DDLS) objectively measured by a nonmydriatic fundus camera, confocal laser scanning ophthalmoscopy (HRT3), and spectral-domain optical coherence tomography (SD-OCT) in uveitic glaucoma. A total of 59 patients with uveitic glaucoma (21 female, 38 male; mean age 56.8 ± 18.7 years) were included in this prospective cross-sectional study. All patients were measured by the Kowa Nonmyd WX 3D camera (2D/3D nonmydriatic retinal camera, Kowa Company), the HRT3 (Heidelberg Engineering), and SD-OCT (Carl Zeiss Meditec) by one examiner on the same day. All 3 devices graded the optic disc topography ...

      Read Full Article
    19. Gabor optical coherence tomographic angiography (GOCTA) (Part I): human retinal imaging in vivo

      Gabor optical coherence tomographic angiography (GOCTA) (Part I): human retinal imaging in vivo

      Recently, parallel high A-line speed and wide field imaging for optical coherence tomography angiography (OCTA) has become more prevalent, resulting in a dramatic increase of data quantity which poses a challenge for real time imaging even for GPU in data processing. In this manuscript, we propose a new OCTA processing technique, Gabor optical coherence tomographic angiography (GOCTA), for label-free human retinal angiography imaging. In spectral domain optical coherence tomography (SDOCT), k-space resampling and Fourier transform (FFT) are required for the entire data set of interference fringes to calculate blood flow information in previous OCTA algorithms, which are computationally intensive. As ...

      Read Full Article
    20. Comparison of optical coherence tomography findings and visual field changes in patients with primary open-angle glaucoma and amyotrophic lateral sclerosis

      Comparison of optical coherence tomography findings and visual field changes in patients with primary open-angle glaucoma and amyotrophic lateral sclerosis

      Recent studies revealing genetic connection of primary open angle glaucoma (POAG) and amyotrophic lateral sclerosis (ALS) have received particular attention. Exploring the evidence for common pathogenesis of these two progressive neurological disorders may assist in understanding the mechanism and searching for new treatment. Retinal nerve fiber layer (RNFL) defect and corresponding visual field (VF) impairment are well known neuropathy signs in glaucoma. In our study, thickness of certain retinal layer in ALS patients was analyzed to detect ganglion cell’s soma and axon, and for first time visual field was examined for ALS. The correlation of retinal involvement and ALS ...

      Read Full Article
    21. Automated detection of exudative age-related macular degeneration in spectral domain optical coherence tomography using deep learning

      Automated detection of exudative age-related macular degeneration in spectral domain optical coherence tomography using deep learning

      Purpose Our purpose was to use deep learning for the automated detection of age-related macular degeneration (AMD) in spectral domain optical coherence tomography (SD-OCT). Methods A total of 1112 cross-section SD-OCT images of patients with exudative AMD and a healthy control group were used for this study. In the first step, an open-source multi-layer deep convolutional neural network (DCNN), which was pretrained with 1.2 million images from ImageNet, was trained and validated with 1012 cross-section SD-OCT scans (AMD: 701; healthy: 311). During this procedure training accuracy, validation accuracy and cross-entropy were computed. The open-source deep learning framework TensorFlow™ (Google ...

      Read Full Article
    22. Qualitative and quantitative assessment of cartilage degeneration using full-field optical coherence tomography ex vivo

      Qualitative and quantitative assessment of cartilage degeneration using full-field optical coherence tomography ex vivo

      Objective The purpose of this study was to investigate the ability of full-field optical coherence tomography (FFOCT) to qualitatively and quantitatively evaluate cartilage degeneration using the qualitative evaluation of histology sections as the reference. Design 33 human knee cartilage samples of variable degeneration were included in the study. A closely matching histology and FFOCT image was acquired for each sample. The cartilage degeneration was qualitatively evaluated by assigning a grade to each histology and FFOCT image. The relevance of the performed grading was assessed by calculating the intra- and inter-observer reproducibility and calculating the concordance between the histology and FFOCT ...

      Read Full Article
    23. The application of optical coherence tomography angiography in retinal diseases

      The application of optical coherence tomography angiography in retinal diseases

      Optical coherence tomography angiography (OCTA) is a new, noninvasive imaging technique that generates real-time volumetric data on chorioretinal vasculature and its flow pattern. With the advent of high-speed optical coherence tomography, established en face chorioretinal segmentation, and efficient algorithms, OCTA generates images that resemble an angiogram. The principle of OCTA involves determining the change in backscattering between consecutive B-scans and then attributing the differences to the flow of erythrocytes through retinal blood vessels . OCTA has shown promise in the evaluation of common ophthalmologic diseases such as diabetic retinopathy , age-related macular degeneration , and retinal vascular occlusions . It quantifies vascular compromise reflecting ...

      Read Full Article
    577-600 of 10399 « 1 2 ... 22 23 24 25 26 27 28 ... 432 433 434 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Popular Articles

  3. Organizations in the News

    1. (4 articles) Oregon Health & Science University
    2. (3 articles) Center for Ophthalmic Optics and Lasers
    3. (2 articles) UCLA
    4. (2 articles) UCSD
    5. (2 articles) Medical University of Vienna
    6. (2 articles) Harvard University
    7. (2 articles) University of Wisconsin
    8. (1 articles) Università Vita-Salute San Raffaele
    9. (1 articles) University of Coimbra
    10. (1 articles) National Cancer Institute
    11. (1 articles) FDA
    12. (1 articles) New York Eye and Ear Infirmary
  4. People in the News

    1. (3 articles) David Huang
    2. (2 articles) Srinivas R. Sadda
    3. (2 articles) Tadamichi Akagi
    4. (2 articles) Ursula Schmidt-Erfurth
    5. (2 articles) Robert N. Weinreb
    6. (2 articles) Joseph Carroll
    7. (2 articles) Linda M. Zangwill
    8. (1 articles) Chunhui Jiang
    9. (1 articles) K. Bailey Freund
    10. (1 articles) Tien Yin Wong
    11. (1 articles) Yali Jia
    12. (1 articles) Maciej Szkulmowski
  5. OCT Companies in the News

    1. (4 articles) Topcon Medical Systems
    2. (4 articles) Carl Zeiss Meditec
    3. (3 articles) Optovue
    4. (3 articles) Heidelberg Engineering
    5. (1 articles) Tomey Corporation
    6. (1 articles) Optos