1. All Articles

    25-48 of 19840 « 1 2 3 4 5 ... 825 826 827 »
    1. Nonglaucomatous Cupping: Fundus Photography and Spectral Domain Optical Coherence Tomography Imaging Features

      Nonglaucomatous Cupping: Fundus Photography and Spectral Domain Optical Coherence Tomography Imaging Features

      Nonglaucomatous cupping is commonly encountered in neuro-ophthalmic practice. However, the progression of clinical and imaging findings over time has not been well described. We present serial fundus photographs and spectral domain optical coherence tomography from a pediatric patient with neuromyelitis optic spectrum disorder, which demonstrated progression of both cupping and optic atrophy in the setting of normal intraocular pressure.

      Read Full Article
      Mentions: Duke University
    2. Study finds SD-OCT most reliable test

      Study finds SD-OCT most reliable test

      Researchers found that spectral-domain optical coherence tomography, when used alone, had better expert agreement when comparing its diagnostic performance with stereoscopic disc photographs and automated perimetry in differentiating individuals with early glaucoma from suspects. The study from Investigative Ophthalmology & Visual Science compared 46 eyes from 46 patients with suspicious optic nerves who had previously underwent spectral-domain optical coherence tomography scans, 24-2 visual fields and optic disc photographs. Four glaucoma specialists studied the 138 diagnostic tests and classified the patient as likely glaucomatous or nonglaucomatous based on the results of a single test. Interobserver agreement for the glaucoma specialists across the ...

      Read Full Article
    3. The Characteristics of Peripapillary Retinal Perfusion by Optical Coherence Tomography Angiography in Tessellated Fundus Eyes

      The Characteristics of Peripapillary Retinal Perfusion by Optical Coherence Tomography Angiography in Tessellated Fundus Eyes

      Purpose To evaluate the peripapillary and perifoveal retinal perfusions of young healthy eyes with a tessellated fundus using optical coherence tomography (OCT) angiography. Methods Thirty-five Chinese subjects with a tessellated fundus and 35 subjects without a tessellated fundus from a population-based cross-sectional study in Shanghai were included. All participants underwent OCT angiography. The flow index and vessel density were examined in the peripapillary and perifoveal retinal areas, and their relationships with other ocular parameters were analyzed. Results In the peripapillary area, the eyes with a tessellated fundus had a lower retinal nerve fiber layer (RNFL) flow index (0.055 ± 0 ...

      Read Full Article
    4. Diagnostics/Optical Coherence Tomography: Light source calibration for accurate depth readings from FD-OCT

      Diagnostics/Optical Coherence Tomography: Light source calibration for accurate depth readings from FD-OCT

      Producing accurate depth information with Fourier-domain optical coherence tomography (FD-OCT) depends on proper light source calibration; there are different considerations for nonlinear sampling in the two primary FD-OCT implementations: spectral-domain (SD-OCT) and swept-source (SS-OCT). Fourier-domain optical coherence tomography (FD-OCT) is a coherence gating technique. It acquires, as a function of optical wavenumber, the interferometric signal generated by mixing backscattered light from the sample with reference light at a fixed group delay. Back-reflection or backscattered light from samples at different delays generates oscillations or fringes in the interference spectrum. Increased delay produces higher oscillation frequency in the interference spectrum. It is ...

      Read Full Article
      Mentions: Exalos Marcus Duelk
    5. Optical Coherence Tomography, a new tool for pre-clinical research applications

      Optical Coherence Tomography, a new tool for pre-clinical research applications

      Leica Microsystems now offers Optical Coherence Tomography (OCT), imaging systems which utilize optical interferometry, similar to holography, to produce images of internal tissue microstructures. This new and non-invasive tool can be applied to clinical ophthalmology and pre-clinical research . Besides that, it uses low-power, near-infrared light to create cross-sectional views of the target structure. Thanks to these characteristics, the Optical Coherence Tomography imaging systems provide customers with non-contact real-time imaging for enhanced visualization, publishing, examination, and diagnosis. Credit: Leica Microsystems Whether the aim is to improve productivity in translational research or reduce costs associated with pre-clinical discovery and development, the Bioptigen ...

      Read Full Article
      Mentions: Bioptigen Leica
    6. Retinal Nerve Fiber Layer Thickness Measured with Two Different Spectral Domain Optical Coherence Tomography Devices

      Retinal Nerve Fiber Layer Thickness Measured with Two Different Spectral Domain Optical Coherence Tomography Devices

      Purpose To assess the agreement and compare the performance of glaucoma diagnosis of peripapillary retinal nerve fiber layer (RNFL) thickness measurements between two different spectral-domain optical coherence tomography (SD-OCT) devices. Methods Eighty nine eyes of 56 patients with glaucoma and 42 eyes of 25 healthy individuals were imaged with Cirrus and Spectralis OCT in a single visit. Agreement between RNFL thickness measurements was assessed using intraclass coefficient (ICC) and Bland-Altman plots. The discriminating abilities of the two techniques for detection of glaucoma were compared by the area under the receiver operating characteristic curves (AUC) for quadrants and average RNFL thickness ...

      Read Full Article
    7. Comparison of Optical Coherence Tomography Characteristics among Three Subtypes of Exudative Age-related Macular Degeneration

      Comparison of Optical Coherence Tomography Characteristics among Three Subtypes of Exudative Age-related Macular Degeneration

      Abstract Purpose To compare the characteristics of optical coherence tomography in eyes with treatment-naïve typical neovascular age-related macular degeneration (typical nAMD), polypoidal choroidal vasculopathy (PCV), and retinal angiomatous proliferation (RAP). Methods One hundred fifty-three eyes newly diagnosed with exudative AMD were retrospectively collected. All study eyes were classified into three subtypes: typical nAMD, PCV, and RAP. Subfoveal choroidal thickness (SFCT) was measured using enhanced depth imaging optical coherence tomography (EDI-OCT). Central macular thickness (CMT) and other OCT features including intraretinal cystoid fluid and subretinal fluid were also evaluated in all eyes. SFCT, CMT and other OCT features were compared ...

      Read Full Article
    8. Recovery Course of Macular Structure after Macular Hole Surgery: Using a Spectral Domain Optical Coherence Tomography Image

      Recovery Course of Macular Structure after Macular Hole Surgery: Using a Spectral Domain Optical Coherence Tomography Image

      Abstract Purpose To analyze the recovery course of foveal microstructures and evaluate the important structures for visual improvement after vitrectomy for full thickness macular hole (MH) using optical coherence tomography (OCT). Methods We retrospectively reviewed the medical records of 34 cases with idiopathic macular hole. We investigated the healing process of foveal microstructures and visual acuity pre- and post-operatively at 1, 3, 6, 12 months after surgery. We evaluated the integrity of four factors by OCT image: existence of MH (Hole, H 1,3,6,12 ), recovery of outer nuclear layer (ONL, O 1,3,6,12 ), recovery of external ...

      Read Full Article
    9. The Role of Optical Coherence Tomography Angiography in the Diagnosis and Management of Acute Vogt–Koyanagi–Harada Disease

      The Role of Optical Coherence Tomography Angiography in the Diagnosis and Management of Acute Vogt–Koyanagi–Harada Disease

      Purpose : To report the imaging characteristics of acute Vogt–Koyanagi–Harada (VKH) disease using optical coherence tomography angiography (OCTA). Methods : In this prospective study, patients with acute VKH ( n = 10; mean age: 30.5 ± 13.43 years) underwent multimodal imaging (baseline and follow-up) using fundus photography, fluorescein angiography (FA), indocyanine green angiography (ICGA), OCT, and OCTA. The OCTA images were analyzed to assess the retinochoroidal vasculature and compared with other imaging techniques. Results : During the active stage, all eyes showed multiple foci of choriocapillaris flow void that correlated with ICGA. These foci decreased in number and size after initiation of ...

      Read Full Article
      Mentions: Vishali Gupta
    10. Choroidal Morphology and Vascular Analysis in Eyes With Neovascular Age-Related Macular Degeneration Using Spectral-Domain Optical Coherence Tomography

      Choroidal Morphology and Vascular Analysis in Eyes With Neovascular Age-Related Macular Degeneration Using Spectral-Domain Optical Coherence Tomography

      BACKGROUND AND OBJECTIVE: To describe morphology and vascular layer thickness of the choroid in eyes with neovascular age-related macular degeneration (AMD) using spectral-domain optical coherence tomography (SD-OCT). PATIENTS AND METHODS: Cross-sectional, retrospective analysis of 15 eyes with neovascular AMD and 11 healthy age-matched eyes that underwent single horizontal, high-definition raster line imaging using high-definition SD-OCT. Two independent graders assessed choroid morphology and measured the thickness of individual vascular layers of the choroid beneath the fovea. RESULTS: Normal concave choroidal contour was found in 13.3% of eyes with neovascular AMD and 100% of healthy eyes. The thickest point of the ...

      Read Full Article
    11. Peripapillary Retinal Nerve Fiber Layer Vascular Microcirculation in Glaucoma Using Optical Coherence Tomography–Based Microangiography

      Peripapillary Retinal Nerve Fiber Layer Vascular Microcirculation in Glaucoma Using Optical Coherence Tomography–Based Microangiography

      Purpose : To investigate the vascular microcirculation changes in the retinal nerve fiber layer (RNFL) in normal, glaucoma suspect, and open-angle glaucoma (OAG) groups using optical coherence tomography–based microangiography (OMAG). Methods : One eye from each subject was scanned with a Cirrus HD-OCT 5000–based OMAG prototype system montage scanning protocol centered at the optic nerve head (ONH). Blood flow signals were extracted using OMAG algorithm. Retinal nerve fiber layer vascular microcirculation was measured by calculating the blood flux index and vessel area density within a 1.2-mm width annulus centered at the ONH with exclusion of big retinal vessels. One-way ...

      Read Full Article
    12. Retinal Capillary Network and Foveal Avascular Zone in Eyes with Vein Occlusion and Fellow Eyes Analyzed With Optical Coherence Tomography Angiography

      Retinal Capillary Network and Foveal Avascular Zone in Eyes with Vein Occlusion and Fellow Eyes Analyzed With Optical Coherence Tomography Angiography

      Purpose : To evaluate the perifoveolar retinal capillary network at different depths and to quantify the foveal avascular zone (FAZ) in eyes with retinal vein occlusion (RVO) compared with their fellow eyes and healthy controls using spectral-domain optical coherence tomography angiography (SD-OCTA). Methods : We prospectively recruited 23 patients with RVO including 15 eyes with central RVO (CRVO) and 8 eyes with branch RVO (BRVO), their fellow eyes, and 8 age-matched healthy controls (8 eyes) for imaging on prototype OCTA software within RTVue-XR Avanti. The 3 × 3 mm and 6 × 6 mm en face angiograms of superficial and deep retinal capillary plexuses ...

      Read Full Article
    13. Three-dimensional Segmentation of Retinal Cysts from Spectral-domain Optical Coherence Tomography Images by the Use of Three-dimensional Curvelet Based K-SVD

      Three-dimensional Segmentation of Retinal Cysts from Spectral-domain Optical Coherence Tomography Images by the Use of Three-dimensional Curvelet Based K-SVD

      This paper presents a new three-dimensional curvelet transform based dictionary learning for automatic segmentation of intraretinalcysts, most relevant prognostic biomarker in neovascular age-related macular degeneration, from 3D spectral-domain optical coherencetomography (SD-OCT) images. In particular, we focus on the Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany) system, andshow the applicability of our algorithm in the segmentation of these features. For this purpose, we use recursive Gaussian filter and approximatethe corrupted pixels from its surrounding, then in order to enhance the cystoid dark space regions and future noise suppression we introduce anew scheme in dictionary learning and take curvelet transform of filtered image ...

      Read Full Article
    14. Measurement of Corneal Endothelial Surface Area Using Anterior Segment Optical Coherence Tomography in Normal Subjects

      Measurement of Corneal Endothelial Surface Area Using Anterior Segment Optical Coherence Tomography in Normal Subjects

      Purpose: To calculate the number of corneal endothelial cells (CEC) on the posterior surface of the normal human cornea by measuring specific surface areas through anterior segment optical coherence tomography. The effects of age, sex, and variations between the right and left eyes were also investigated. Methods: This study involved 60 eyes of 30 normal subjects with no history of corneal disease. Subjects were divided into the following groups according to age: group A (20-39 years old), group B (40-59 years old), and group C (60-79 years old). Set areas of the corneal posterior surface were imaged and analyzed using ...

      Read Full Article
    15. DIFFERENTIAL MACULAR FEATURES ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN EYES WITH CHOROIDAL NEVUS AND MELANOMA

      DIFFERENTIAL MACULAR FEATURES ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN EYES WITH CHOROIDAL NEVUS AND MELANOMA

      Purpose: To evaluate optical coherence tomography angiography (OCTA) characteristics of macular vascular details in eyes with choroidal nevus and melanoma, compared with unaffected contralateral eye. Methods: Retrospective comparative analysis comprising 70 patients with choroidal nevus and 36 patients with choroidal melanoma examined with optical coherence tomography angiography. Measurements included central macular thickness (CMT), superficial (sFAZ) and deep (dFAZ) foveal avascular zone (FAZ) area, and superficial (sCVD) and deep (dCVD) capillary vascular density (CVD). Results: In patients with nevus, CMT (affected vs. unaffected eye) was similar (267 vs. 265 [mu]m, P = 0.67), whereas in patients with melanoma, CMT demonstrated ...

      Read Full Article
    16. Learning layer-specific edges for segmenting retinal layers with large deformations

      Learning layer-specific edges for segmenting retinal layers with large deformations

      We present an algorithm for layer-specific edge detection in retinal optical coherence tomography images through a structured learning algorithm to reinforce traditional graph-based retinal layer segmentation. The proposed algorithm simultaneously identifies individual layers and their corresponding edges, resulting in the computation of layer-specific edges in 1 second. These edges augment classical dynamic programming based segmentation under layer deformation, shadow artifacts noise, and without heuristics or prior knowledge. We considered Duke’s online data set containing 110 B-scans of 10 diabetic macular edema subjects with 8 retinal layers annotated by two experts for experimentation, and achieved a mean distance error of ...

      Read Full Article
    17. Polarization-sensitive optical coherence tomography-based imaging, parameterization, and quantification of human cartilage degeneration

      Polarization-sensitive optical coherence tomography-based imaging, parameterization, and quantification of human cartilage degeneration

      Polarization-sensitive optical coherence tomography (PS-OCT) is a light-based, high-resolution, real-time, noninvasive, and nondestructive imaging modality yielding quasimicroscopic cross-sectional images of cartilage. As yet, comprehensive parameterization and quantification of birefringence and tissue properties have not been performed on human cartilage. PS-OCT and algorithm-based image analysis were used to objectively grade human cartilage degeneration in terms of surface irregularity, tissue homogeneity, signal attenuation, as well as birefringence coefficient and band width, height, depth, and number. Degeneration-dependent changes were noted for the former three parameters exclusively, thereby questioning the diagnostic value of PS-OCT in the assessment of human cartilage degeneration.

      Read Full Article
    18. Autocorrelation noise free Optical Coherence Tomography using the novel concept of resonant OCT (ROCT)

      Autocorrelation noise free Optical Coherence Tomography using the novel concept of resonant OCT (ROCT)

      Background Optical Coherence Tomography OCT is a noninvasive imaging technique that takes pictures of cross sections of human body tissues with a great resolution compared to other techniques. Fourier Domain OCT method provides significant improvement of imaging speed and detection sensitivity but suffers from autocorrelation noise arising as interference signals from reflections of sample layers that tends to obscure some of sample structure details. Methods We present in this paper a new implementation of Common Path Optical Coherence Tomography, based on a resonant structure. The structure employs a semiconductor optical amplifier SOA and uses two mirrors, one coated fiber end ...

      Read Full Article
    19. YOUR eyes and ears could help diagnose early signs of dementia and THIS is how

      YOUR eyes and ears could help diagnose early signs of dementia and THIS is how

      Scientists have also found an impaired sense of smell may predict dementia and could be an early indicator of the disease. A new study has found the thinning of the retinal nerve at the back of the eye can flag up impending neuro-degeneration. It was linked with poorer performance on cognitive tests including memory, numeric and verbal reasoning and reaction times. A protein called beta-amyloid builds up in the brains of people with Alzheimer's disease - forming into clumps and causing memory loss and confusion...The researchers carried out a type of eye scan called spectral domain optical coherence tomography ...

      Read Full Article
    20. Apparatus and method for space-division multiplexing optical coherence tomography

      Apparatus and method for space-division multiplexing optical coherence tomography

      A space-division multiplexing optical coherence tomography apparatus and system is provided. In one embodiment, the system includes a light source, a reference arm, and a sample arm. The sample arm splits the sampling light into a plurality of sampling beams which may be scanned simultaneously onto a surface of a sample. An optical delay may be introduced into the sampling beams before scanning. A plurality of reflected light signals returned from the sample is collected. In one arrangement, the signals may be combined to produce a single reflected light signal. The reflected light signal(s) and a reference signal are ...

      Read Full Article
    21. OCT probe using PZT

      OCT probe using PZT

      An optical coherence tomography (OCT) probe using lead zirconate titanate (PZT). In the OCT probe using PZT, a sine wave is induced from a vibrator made of a piezoelectric element, so that an image in which the scanning range is increased can be captured due to the vibration of the vibrator. A decrease in the vibration of the vibrator can be minimized by optimizing the position where the base fixes the vibrator.

      Read Full Article
    22. Radial Peripapillary Capillary Network Visualized Using Wide-Field Montage Optical Coherence Tomography Angiography

      Radial Peripapillary Capillary Network Visualized Using Wide-Field Montage Optical Coherence Tomography Angiography

      Purpose : We quantitatively analyzed the features of a radial peripapillary capillary (RPC) network visualized using wide-field montage optical coherence tomography (OCT) angiography in healthy human eyes. Methods : Twenty eyes of 20 healthy subjects were recruited. En face 3 × 3-mm OCT angiograms of multiple locations in the posterior pole were acquired using the RTVue XR Avanti, and wide-field montage images of the RPC were created. To evaluate the RPC density, the montage images were binarized and skeletonized. The correlation between the RPC density and the retinal nerve fiber layer (RNFL) thickness measured by an OCT circle scan was investigated. Results : The ...

      Read Full Article
    25-48 of 19840 « 1 2 3 4 5 ... 825 826 827 »
  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. Optical Coherence Tomography News

    See all Optical Coherence Tomography News articles
  4. Organizations in the News

    1. (621 articles) Harvard University
    2. (524 articles) Massachusetts General Hospital
    3. (510 articles) Massachusetts Institute of Technology
    4. (500 articles) National Institutes of Health
    5. (392 articles) Duke University
    6. (340 articles) University of Miami
    7. (339 articles) Johns Hopkins University
    8. (333 articles) Medical University of Vienna
    9. (306 articles) University of Southern California
    10. (304 articles) FDA
  5. People in the News

    1. (349 articles) James G. Fujimoto
    2. (246 articles) David Huang
    3. (239 articles) Joseph A. Izatt
    4. (227 articles) Ruikang K. Wang
    5. (195 articles) Stephen A. Boppart
    6. (193 articles) Guillermo J. Tearney
    7. (187 articles) Adrian G. Podoleanu
    8. (183 articles) Zhongping Chen
    9. (170 articles) Brett E. Bouma
    10. (168 articles) Patrick W. Serruys
  6. OCT Companies in the News

    1. (1455 articles) Carl Zeiss Meditec
    2. (764 articles) St. Jude Medical
    3. (564 articles) Heidelberg Engineering
    4. (487 articles) Optovue
    5. (329 articles) Topcon Medical Systems
    6. (328 articles) Volcano Corporation
    7. (236 articles) Michelson Diagnostics
    8. (208 articles) Bioptigen
    9. (185 articles) Thorlabs
    10. (140 articles) Axsun Technologies