1. All Articles

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    1. CLINICAL SPECTRUM OF MACULAR-FOVEAL CAPILLARIES EVALUATED WITH OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

      CLINICAL SPECTRUM OF MACULAR-FOVEAL CAPILLARIES EVALUATED WITH OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

      Purpose: To describe macular-foveal capillaries (MFC) by means of optical coherence tomography angiography and to identify the clinical spectrum of this angiographic feature. Methods: Patients with MFC presenting at the Medical Retina & Imaging Unit of the Department of Ophthalmology, University Vita-Salute San Raffaele in Milan were recruited. Patients underwent a complete ophthalmologic examination that included slit-lamp examination, fundus examination, measurement of best-corrected visual acuity, fundus autofluorescence, and spectral-domain optical coherence tomography (Spectralis HRA + OCT; Heidelberg Engineering, Heidelberg, Germany). Fluorescein angiography was performed in selected cases. Optical coherence tomography angiography was performed through Zeiss prototype (AngioPlex, CIRRUS HD-OCT models 5000; Carl ...

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    2. A study on optical coherence tomography using high frequency swept source

      A study on optical coherence tomography using high frequency swept source

      Optical coherence tomography based on ultra technology is used for the assessment of subcutaneous tissue. Using high swept laser technology based on Fourier domain mode locking (FDML), the system operated in the 1300 nm wavelength range with axial scan rate of 150 kHz. Imaging at this wavelength range reduces optical scattering and improves imaging penetration depths in the tissues. The laser consists of a semiconductor amplifier as the gain medium, a tunable Fabry-Perot filter to change the wavelengthcand a long fiber ring cavity. The tuning range of laser is 102 nm. A balanced detector is used for spectra collection instead ...

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    3. Loose powder detection and surface characterization in selective laser sintering via optical coherence tomography

      Loose powder detection and surface characterization in selective laser sintering via optical coherence tomography

      Defects produced during selective laser sintering (SLS) are difficult to non-destructively detect after build completion without the use of X-ray-based methods. Overcoming this issue by assessing integrity on a layer-by-layer basis has become an area of significant interest for users of SLS apparatus. Optical coherence tomography (OCT) is used in this study to detect surface texture and sub-surface powder, which is un-melted/insufficiently sintered, is known to be a common cause of poor part integrity and would prevent the use of SLS where applications dictate assurance of defect-free parts. To demonstrate the capability of the instrument and associated data-processing algorithms ...

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    4. PERIPAPILLARY ARTERIAL RING OF ZINN-HALLER IN HIGHLY MYOPIC EYES AS DETECTED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

      PERIPAPILLARY ARTERIAL RING OF ZINN-HALLER IN HIGHLY MYOPIC EYES AS DETECTED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

      Purpose: To visualize the arterial circle of Zinn-Haller (ZHAC) in highly myopic patients by using OCT-A. Methods: Two hundred and fifty-three eyes of 146 consecutive patients with axial length >=26.5 mm who underwent OCT-A centered onto the optic disk were studied. Results: Arterial circle of Zinn-Haller was detectable on OCT-A images within the area of the parapapillary myopic conus in 26 (10%) of 253 eyes. The ZHAC was annular in 18 (69%) eyes, triangular in (15%) 4 eyes, and irregular (15%) in 4 eyes. The visibility of the ZHAC on OCT-A images was similar to the visibility on indocyanine ...

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    5. Evaluation of Early Graft Detachment After Descemet Membrane Endothelial Keratoplasty Using New Swept-Source Optical Coherence Tomography

      Evaluation of Early Graft Detachment After Descemet Membrane Endothelial Keratoplasty Using New Swept-Source Optical Coherence Tomography

      Purpose: To evaluate the ability of Swept-source optical coherence tomography (SS-OCT) in detecting early endothelial graft detachment after Descemet membrane endothelial keratoplasty (DMEK) and to determine the possible causes of graft detachment using 2 different protocols for anterior segment (AS) imaging. Methods: Eight eyes from 8 consecutive DMEK surgeries were evaluated. High-resolution images were captured with SS-OCT using 2 different radial protocols for AS imaging (16- and 6-mm radial protocols). Central and peripheral corneal changes were evaluated. Results: All eyes developed early graft detachment detectable with the SS-OCT. The 16-mm radial protocol scanned the cornea detecting early graft detachment in ...

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    6. OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY ASSESSMENT OF VASCULAR EFFECTS OCCURRING AFTER AFLIBERCEPT INTRAVITREAL INJECTIONS IN TREATMENT-NAIVE PATIENTS WITH WET AMD

      OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY ASSESSMENT OF VASCULAR EFFECTS OCCURRING AFTER AFLIBERCEPT INTRAVITREAL INJECTIONS IN TREATMENT-NAIVE PATIENTS WITH WET AMD

      Purpose: To investigate vessel changes occurring after aflibercept injections in treatment-naive exudative age-related macular degeneration patients. Methods: Fifteen eyes of 15 patients affected by wet age-related macular degeneration were enrolled in the study. All the patients had a diagnosis of Type 1 choroidal neovascularization and were treated with 3 monthly aflibercept intravitreal injections (IVI). Subjects were evaluated by means of optical coherence tomography angiography at baseline, the day after the first injection and one month after both the first and the second IVI. At last, all the patients were followed up to 2 months after the third IVI. Results: Foveal ...

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    7. SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY-BASED MICROSTRUCTURAL ANALYSIS OF RETINAL ARCHITECTURE POST INTERNAL LIMITING MEMBRANE PEELING FOR SURGERY OF IDIOPATHIC MACULAR HOLE REPAIR

      SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY-BASED MICROSTRUCTURAL ANALYSIS OF RETINAL ARCHITECTURE POST INTERNAL LIMITING MEMBRANE PEELING FOR SURGERY OF IDIOPATHIC MACULAR HOLE REPAIR

      Purpose: Spectral domain optical coherence tomography-based analysis of retinal architecture after internal limiting membrane peeling for macular hole surgery. Methods: Prospective, interventional study. Fifty eyes underwent the surgical procedure with minimum internal limiting membrane peel of 3 mm diameter. Automatic segmentation software was used to assess individual layers preoperatively and postoperatively, 1.5 millimeters medial and lateral to fovea at 3 months postoperative visit. Main outcome measures were final central macular thickness and variation in individual retinal layer thickness. Results: Mean central macular thickness postoperatively was 201 microns. Retinal thickening was observed, 1.5 mm medial to fovea (P < 0 ...

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    8. Evaluation of the conjuntival blebs using spectral domain optical coherence tomography after glaucoma surgery

      Evaluation of the conjuntival blebs using spectral domain optical coherence tomography after glaucoma surgery

      Objective to investigate whether optical coherence tomography (OCT) could demonstrate axonal loss through thinning of the retinal nerve fiber layer (RNFL) in multiple sclerosis (MS) patients. Furthermore, the degree of RNFL loss was compared in the different MS subgroups (with or without optic neuritis, affected or fellow eye, single episode or recurrent optic neuritis, relapsing remitting or progressive MS). RNFL thinning was also determined in MS patients who had serial OCT without any intervening clinical optic neuritis. Design: Retrospective chart review. Setting: Academic tertiary care MS centers. Participants: 177 patients (334 eyes) with multiple sclerosis, with or without optic neuritis ...

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    9. The new kid on the block for advanced imaging in Barrett’s esophagus: a review of volumetric laser endomicroscopy

      The new kid on the block for advanced imaging in Barrett’s esophagus: a review of volumetric laser endomicroscopy

      Advanced imaging techniques used in the management of Barrett’s esophagus include electronic imaging enhancement (e.g. narrow band imaging, flexible spectral imaging color enhancement, and i-Scan), chromoendoscopy, and confocal laser endomicroscopy. Electronic imaging enhancement is used frequently in daily practice, but use of the other advanced technologies is not routine. High-definition white light endoscopy and random four quadrant biopsy remain the standard of care for evaluation of Barrett’s esophagus; this is largely due to the value of advanced imaging technologies not having been validated in large studies or in everyday practice. A new advanced imaging technology called volumetric ...

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    10. Volumetric laser endomicroscopy can target neoplasia not detected by conventional endoscopic measures in long segment Barrett’s esophagus

      Volumetric laser endomicroscopy can target neoplasia not detected by conventional endoscopic measures in long segment Barrett’s esophagus

      Methods and study aims: The incidence of esophageal cancer is rising despite increased surveillance efforts. Volumetric laser endomicroscopy (VLE) is a new endoscopic imaging tool that can allow for targeted biopsy of neoplasia in Barrett’s esophagus. We report a series of 6 patients with long-segment Barrett’s esophagus ( > 3 cm), who underwent a session of endoscopy with volumetric laser endomicroscopy, after a separate prior session of standard high-definition endoscopy with narrow band imaging (NBI) and random biopsies that did not reveal neoplasia. In all six patients, the first endoscopy was the index endoscopy diagnosing the Barrett’s esophagus. All ...

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    11. University of California at Berkely Receives NIH Grant for Interferometric Optophysiology of the Human Retina

      University of California at Berkely Receives NIH Grant for Interferometric Optophysiology of the Human Retina

      University of California at Berkeley Receives a 2016 NIH Grant for $662,015 for Interferometric Optophysiology of the Human Retina. The principal investigator is Austin Roorda. The program began in 2015 and ends in 2020. Below is a summary of the proposed work. Our goal is to develop a new technology for non-invasive optical monitoring of activity of individual retinal neurons and their light-driven inputs at cellular resolution, in the living human retina. If successful, this technology will provide an entirely new and objective approach to understand and monitor treatment of retinal disease, thereby transforming scientific studies of the eye ...

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    12. OCT Medical Imaging Inc. Receives a NIH Grant for Clinical Evaluation and Development of a Diagnostic Multi-modal Intravascular Imaging System

      OCT Medical Imaging Inc. Receives a NIH Grant for Clinical Evaluation and Development of a Diagnostic Multi-modal Intravascular Imaging System

      OCT Medical Imaging Inc. Receives a 2016 NIH Grant for $1,252,899 for Clinical Evaluation and Development of a Diagnostic Multi-modal Intravascular Imaging System. The principal investigator is Tirunelveli Ramalingam. The program began in 2015 and ends in 2018. Below is a summary of the proposed work. Understanding that not a single imaging technique can alone address needs of all vascular diagnosis, OCT medical imaging Inc. (OCTMI) propose to develop a clinical multimodal intravascular imaging system encompassing ultra-high resolution optical coherence tomography (OCT) and IVUS. This Combined multimodal vascular imaging system will permit cross-sectional visualization of vascular artery with ...

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    13. Johns Hopkins University Receives a NIH Grant for OCT to Distinguish BT Tumor & Non-Tumor Tissue in Infiltrating Brain Cancer

      Johns Hopkins University Receives a NIH Grant for OCT to Distinguish BT Tumor & Non-Tumor Tissue in Infiltrating Brain Cancer

      Johns Hopkins University Receives a 2016 NIH Grant for $48,576 for OCT to Distinguish BT Tumor & Non-Tumor Tissue in Infiltrating Brain Cancer. The principal investigator is Carmen Kut. The program began in 2014 and ends in 2017. Below is a summary of the proposed work. In brain cancers such as gliomas, aggressive removal of the solid tumor through surgery is associated with improved overall survival. In fact, i has been shown that at least 78% of the tumor has to be removed to make a meaningful difference in the patient's survival. Current techniques for tumor removal are limited ...

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    14. Johns Hopkins University Receives a NIH Grant for Tissue Pharmacology Imaging and Modeling

      Johns Hopkins University Receives a NIH Grant for Tissue Pharmacology Imaging and Modeling

      Johns Hopkins University Receives a 2016 NIH Grant for $542,099 for Tissue Pharmacology Imaging and Modeling. The principal investigator is Namandjen Bumpus. The program began in 2016 and ends in 2017. Below is a summary of the proposed work. A successful microbicide product has pharmacokinetics (PK) that effect prophylactic pharmacodynamics (PD). Product design should manipulate candidate compositions, volumes, and drug packaging in a rational manner to yield target PK/PD; but we have limited understanding of this relationship. Further, our methods for experimentally evaluating PK in animals and humans are limited: they do not delineate drug concentration distributions throughout ...

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    15. Evaluation of a Micro-Optical Coherence Tomography for the Corneal Endothelium in an Animal Model

      Evaluation of a Micro-Optical Coherence Tomography for the Corneal Endothelium in an Animal Model

      Recent developments in optical coherence tomography (OCT) systems for the cornea have limited resolution or acquisition speed. In this study we aim to evaluate the use of a ‘micro-OCT’ (μOCT ~1 μm axial resolution) compared to existing imaging modalities using animal models of corneal endothelial disease. We used established cryoinjury and bullous keratopathy models in Sprague Dawley rats comparing ex vivo μOCT imaging in normal and diseased eyes to (1) histology; (2) in vivo confocal microscopy (IVCM); and (3) scanning electron microscopy (SEM). Qualitative and quantitative comparisons amongst imaging modalities were performed using mean endothelial cell circularity [(4π × Area)/Perimeter ...

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    16. Toward High-Speed Imaging of Cellular Structures in Rat Colon Using Micro-optical Coherence Tomography

      Toward High-Speed Imaging of Cellular Structures in Rat Colon Using Micro-optical Coherence Tomography

      The mucosal microanatomy of the large intestine is characterized by the presence of crypts of Lieberkühn, which is associated predominantly with goblet cells. Such cellular-level intestinal microstructures undergo morphological changes during the progression of bowel diseases, such as colon cancer or ulcerative colitis. As an indicator of gastric cancers, intestinal metaplasia in the large intestine is characterized by the appearance of goblet cells in gastric epithelium, and therefore, visualization of intestinal microstructure changes in cross-sectional view, particularly in vivo, in a highspeed fashion would assist early disease diagnosis and its treatment. In this paper, we investigated the capability of ...

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    17. Impact of optical coherence tomography- and coronary angioscopy-assessed neointimal tissue characteristics on occurrence of periprocedural myonecrosis in patients with in-stent restenosis

      Impact of optical coherence tomography- and coronary angioscopy-assessed neointimal tissue characteristics on occurrence of periprocedural myonecrosis in patients with in-stent restenosis

      Several characteristics of neointimal tissues, including neoatherosclerotic progression, have been reported in lesions with in-stent restenosis (ISR). However, the effects of these characteristics on outcomes after percutaneous coronary intervention (PCI) for ISR lesions remain unclear. We assessed the relationships between neointimal tissue characteristics and the occurrence of periprocedural myonecrosis (PMN) after PCI in ISR lesions. We investigated 72 ISR lesions in 72 patients with stable angina pectoris (SAP) who underwent pre- and post-revascularization optical coherence tomography (OCT) and coronary angioscopy (CAS). All lesions were classified as with PMN, defined by an elevated peak high-sensitivity cardiac troponin-T level during the 24-h ...

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    18. Evaluation of Early Healing Profile and Neointimal Transformation Over 24 Months Using Longitudinal Sequential Optical Coherence Tomography Assessments and 3-Year Clinical Results of the New Dual-Therapy Endothelial Progenitor Cell Capturing Sirolimus-Elu

      Evaluation of Early Healing Profile and Neointimal Transformation Over 24 Months Using Longitudinal Sequential Optical Coherence Tomography Assessments and 3-Year Clinical Results of the New Dual-Therapy Endothelial Progenitor Cell Capturing Sirolimus-Elu

      Background— Current monotherapy drug-eluting stents are associated with impaired healing, neoatherosclerosis, and late stent thrombosis. The healing profile and neointimal transformation of the first dual-therapy endothelial progenitor cell–capturing sirolimus-eluting stent are unknown. Methods and Results— In this prospective, single-center study, 61 patients treated with the Combo stent had optical coherence tomography at baseline, early follow-up (4 monthly groups in a 1:2:2:1 ratio from 2 to 5 months), 9 months, and 24 months. Optical coherence tomography early strut coverage increased from 77.1% to 92.5% to 92.7% to 94.9% between 2 and 5 months ...

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    19. Delineation of capillary dropout in the deep retinal capillary plexus using optical coherence tomography angiography in a patient with Purtscher’s retinopathy exhibiting normal fluorescein angiography findings: a case report

      Delineation of capillary dropout in the deep retinal capillary plexus using optical coherence tomography angiography in a patient with Purtscher’s retinopathy exhibiting normal fluorescein angiography findings: a case report

      Background Fat embolism in the deep retinal capillary plexus is one of the reported mechanisms underlying central/paracentral scotoma in patients with Purtscher’s retinopathy. Here we report the clear delineation of capillary dropout in the deep capillary plexus using optical coherence tomography angiography (OCTA) in a chronic case of unexplained scotoma that developed after femoral fracture. The patient exhibited normal fluorescein angiography (FA) findings and a normal retinal appearance. Case presentation A 42-year-old Japanese man with a history of bilateral, unexplained paracentral scotoma that developed after femoral fracture and pulmonary fat embolism due to a car accident 20 years ...

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    20. Enhanced low-rank + sparsity decomposition for speckle reduction in optical coherence tomography

      Enhanced low-rank + sparsity decomposition for speckle reduction in optical coherence tomography

      Speckle artifacts can strongly hamper quantitative analysis of optical coherence tomography (OCT), which is necessary to provide assessment of ocular disorders associated with vision loss. Here, we introduce a method for speckle reduction, which leverages from low-rank + sparsity decomposition (LRpSD) of the logarithm of intensity OCT images. In particular, we combine nonconvex regularization-based low-rank approximation of an original OCT image with a sparsity term that incorporates the speckle. State-of-the-art methods for LRpSD require a priori knowledge of a rank and approximate it with nuclear norm, which is not an accurate rank indicator. As opposed to that, the proposed method provides ...

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    21. Magnetic and Plasmonic Contrast Agents in Optical Coherence Tomography

      Magnetic and Plasmonic Contrast Agents in Optical Coherence Tomography

      Optical coherence tomography (OCT) has gained widespread application for many biomedical applications, yet the traditional array of contrast agents used in incoherent imaging modalities do not provide contrast in OCT. Owing to the high biocompatibility of iron oxides and noble metals, magnetic and plasmonic nanoparticles, respectively, have been developed as OCT contrast agents to enable a range of biological and pre-clinical studies. Here, we provide a review of these developments within the past decade, including an overview of the physical contrast mechanisms and classes of OCT system hardware add-ons needed for magnetic and plasmonic nanoparticle contrast . A comparison of the ...

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    22. Optical Coherence Tomography Angiography Findings in Coats' Disease

      Optical Coherence Tomography Angiography Findings in Coats' Disease

      BACKGROUND AND OBJECTIVE: To describe optical coherence tomography angiography (OCTA) findings in patients with unilateral Coats' disease. PATIENTS AND METHODS: Retrospective, observational case series of four patients with unilateral Coats' disease who underwent bilateral OCTA imaging. RESULTS: Bilateral macular OCTA findings of eight eyes are described. An abnormal foveal avascular zone (FAZ) with inner retinal vessels traversing the avascular zone in the superficial capillary plexus was visible on OCTA in the affected eye of all four patients. A similarly abnormal FAZ was noted on OCTA in the clinically normal fellow eye in two of the four patients (50%). CONCLUSION: OCTA ...

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    23. Optical Coherence Tomography Angiography in Fovea Plana

      Optical Coherence Tomography Angiography in Fovea Plana

      Fovea plana is characterized by the anatomical absence of the foveal pit in eyes with normal visual function. The authors have analyzed three cases of idiopathic fovea plana with optical coherence tomography angiography (OCTA). As previously reported, the authors found the absence of a foveal avascular zone in all cases with OCTA; however, a preserved fusion of both the superficial and the deep capillary plexuses was found around the foveal center. This novel observation cannot be detected with conventional dye-based angiography, in which the deep capillary plexus is not visualized.

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    24. Optical Coherence Tomography Evaluation of Valsalva-Induced Suprachoroidal Hemorrhage

      Optical Coherence Tomography Evaluation of Valsalva-Induced Suprachoroidal Hemorrhage

      Suprachoroidal hemorrhage is typically observed in patients with hypotony in the context of intraocular surgery and trauma. We report a rare presentation of suprachoroidal hemorrhage associated with emesis (Valsalva maneuver) in a myopic patient with few other identifiable risk factors. This diagnosis was confirmed with wide-field fundus photography and B-scan ultrasound and was localized to the suprachoroidal space using both enhanced depth and swept-source optical coherence tomography imaging. This case is unique in its presentation and demonstrates the utility of newer imaging techniques to localize hemorrhages using a multimodal approach.

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