1. 49-72 of 849 « 1 2 3 4 5 6 ... 34 35 36 »
    1. Measuring polarization changes in the human outer retina with polarization‐sensitive optical coherence tomography

      Measuring polarization changes in the human outer retina with polarization‐sensitive optical coherence tomography

      Morphological changes in the outer retina such as drusen are established biomarkers to diagnose age‐related macular degeneration. However, earlier diagnosis might be possible by taking advantage of more subtle changes that accompany tissues that bear polarization‐altering properties. To test this hypothesis, we developed a method based on polarization‐sensitive optical coherence tomography with which volumetric data sets of the macula were obtained from 10 young (<25 years) and 10 older (>54 years) subjects. All young subjects and 5 of the older subjects had retardance values induced by the retinal pigment epithelium and Bruch's membrane (RPE‐BM) complex ...

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    2. Trimodal system for in vivo skin cancer screening with combined optical coherence tomography‐Raman and colocalized optoacoustic measurements

      Trimodal system for in vivo skin cancer screening with combined optical coherence tomography‐Raman and colocalized optoacoustic measurements

      A new multimodal system for rapid, noninvasive in vivo skin cancer screening is presented, combining optical coherence tomography (OCT) and optoacoustic (OA) modalities to provide precise tumor depth determination with a Raman spectroscopic modality capable of detecting the lesion type and, thus, providing diagnostic capability. Both OA and Raman setups use wide field skin illumination to ensure the compliance with maximum permissible exposure (MPE) requirements. The Raman signal is collected via the OCT scanning lens to maximize the signal‐to‐noise ratio of the measured signal while keeping radiation levels below MPE limits. OCT is used to optically determine the ...

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    3. Clinical findings and normative ocular data for free-living Anna's (Calypte anna) and Black-chinned (Archilochus alexandri) Hummingbirds

      Clinical findings and normative ocular data for free-living Anna's (Calypte anna) and Black-chinned (Archilochus alexandri) Hummingbirds

      Objective To estimate the prevalence of ocular disease and obtain normative ocular data for free-living hummingbirds. Animals studied Two hundred and sixty-three free-living, adult Hummingbirds from coastal and inland central California were studied, including Anna's ( Calypte anna , n = 186) and Black-chinned ( Archilochus alexandri ; n = 77) hummingbirds. Procedures Slit lamp biomicroscopy and indirect ophthalmoscopy were performed on all individuals. Rebound tonometry, measurement of horizontal palpebral fissure length, and streak retinoscopy were performed on select individuals. Five conscious Anna's Hummingbirds underwent ocular imaging including fundus photography, digital slit lamp photography, and anterior segment and retinal optical coherence tomography. Results The ...

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      Mentions: UC Davis
    4. Is optical coherence tomography a coherent strategy for carotid artery stenting?

      Is optical coherence tomography a coherent strategy for carotid artery stenting?

      Optical coherence tomography (OCT) is rarely necessary to guide clinical decisions about the appropriateness of carotid revascularization. For carotid artery stenting (CAS), computed tomography angiography is the best imaging tool to assess arch, carotid, and lesion-specific anatomy, including vessel dimensions and calcification. OCT is a coherent strategy after CAS to assess ambiguous angiographic findings and to guide appropriate therapy for dissection, thrombosis, and plaque prolapse.

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    5. Optometry-facilitated teleophthalmology: an audit of the first year in Western Australia

      Optometry-facilitated teleophthalmology: an audit of the first year in Western Australia

      Background Lions Outback Vision has run a state-wide teleophthalmology service since 2011. In September 2015 the Australian federal government introduced a Medicare reimbursement for optometry-facilitated teleophthalmology consultations under specific circumstances. This audit demonstrates the first 12 months experience with this scheme. We aim to provide practical insights for others looking to embed a telemedicine program as part of delivering outreach clinical services. Methods A 12-month retrospective audit was performed between September 2015 and August 2016, inclusive. A research officer used a specifically designed data extraction tool to record information from all teleophthalmology consultations performed in the time period. The primary ...

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    6. Optometry‐facilitated teleophthalmology: an audit of the first year in Western Australia

      Optometry‐facilitated teleophthalmology: an audit of the first year in Western Australia

      Background Lions Outback Vision has run a state‐wide teleophthalmology service since 2011. In September 2015 the Australian federal government introduced a Medicare reimbursement for optometry‐facilitated teleophthalmology consultations under specific circumstances. This audit demonstrates the first 12 months experience with this scheme. We aim to provide practical insights for others looking to embed a telemedicine program as part of delivering outreach clinical services. Methods A 12‐month retrospective audit was performed between September 2015 and August 2016, inclusive. A research officer used a specifically designed data extraction tool to record information from all teleophthalmology consultations performed in the time ...

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    7. A novel image processing workflow for the in vivo quantification of skin microvasculature using dynamic optical coherence tomography

      A novel image processing workflow for the in vivo quantification of skin microvasculature using dynamic optical coherence tomography

      Background Currently, imaging technologies that can accurately assess or provide surrogate markers of the human cutaneous microvessel network are limited. Dynamic optical coherence tomography (D-OCT) allows the detection of blood flow in vivo and visualization of the skin microvasculature. However, image processing is necessary to correct images, filter artifacts, and exclude irrelevant signals. The objective of this study was to develop a novel image processing workflow to enhance the technical capabilities of D-OCT. Materials and methods Single-center, vehicle-controlled study including healthy volunteers aged 18-50 years. A capsaicin solution was applied topically on the subject's forearm to induce local inflammation ...

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    8. Biomechanical analysis of decellularized dermis and skin: Initial in vivo observations using OCT and vibrational analysis

      Biomechanical analysis of decellularized dermis and skin: Initial in vivo observations using OCT and vibrational analysis

      Measurement of the mechanical properties of skin in vivo has been complicated by the lack of methods that can accurately measure the viscoelastic properties without assuming values of Poisson's ratio and tissue density. In this paper, we present the results of preliminary studies comparing the mechanical properties of skin and scar tissue measured using a technique involving OCT and vibrational analysis. This technique has been reported to give values of the modulus that correlate with those obtained from tensile measurements made on decellularized dermis [1, 2]. The high correlation between moduli measured using vibrational studies and uniaxial tensile tests ...

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    9. Choroidal thickness at age 66 years in the Danish high myopia study cohort 1948 compared with follow-up data on visual acuity over 40 years: a clinical update adding spectral domain optical coherence tomography

      Choroidal thickness at age 66 years in the Danish high myopia study cohort 1948 compared with follow-up data on visual acuity over 40 years: a clinical update adding spectral domain optical coherence tomography

      Background and purpose A population-based Copenhagen birth year 1948 cohort with high myopia recorded since age 14 years (spherical equivalent less than or equivalent to −6 D) has been followed over 50 years. Despite complications, current follow-ups have outlined a better visual prognosis than usually drawn from selected clinical series in the literature. For the present status at age 66 years, focus was on visual ability and choroidal thickness. Methods Twenty-eight of the original 39 participants were available in 2014. Medical history was updated. Best-corrected visual acuity (BCVA) data were compared with subfoveal choroidal thickness (SFCT), now measured by enhanced ...

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    10. Glaucomatous progression in the retinal nerve fibre and retinal ganglion cell-inner plexiform layers determined using optical coherence tomography-guided progression analysis

      Glaucomatous progression in the retinal nerve fibre and retinal ganglion cell-inner plexiform layers determined using optical coherence tomography-guided progression analysis

      Background To investigate the characteristics of glaucomatous progression in circumpapillary retinal nerve fibre layer (RNFL) and macular retinal ganglion cell-inner plexiform layer (GCIPL) determined using optical coherence tomography-guided progression analysis (OCT-GPA). Methods Serial OCT images of 527 glaucomatous eyes with greater than four OCT tests were screened. Among them, 106 (20.1 per cent) eyes with progression in either RNFL or GCIPL determined using OCT-GPA were included. Based on the agreement of progression detection between RNFL and GCIPL, the eyes were classified into the ‘RNFL progression earlier group’, ‘GCIPL progression earlier group’, or ‘simultaneous progression group’. The type of progression ...

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    11. Photodynamic opening of the blood-brain barrier and pathways of brain clearing

      Photodynamic opening of the blood-brain barrier and pathways of brain clearing

      A new application of the photodynamic treatment (PDT) is presented for the opening of blood-brain barrier (BBB) and the brain clearing activation that is associated with it, including the use of gold nanoparticles as emerging photosensitizer carriers in PDT. The obtained results clearly demonstrate two pathways for the brain clearing: 1) using PDT-opening of BBB and intravenous injection of FITC-dextran we showed a clearance of this tracer via the meningeal lymphatic system in the subdural space; 2) using optical coherence tomography and intra-parenchymal injection of gold nanorods we observed their clearance through the exit gate of cerebral spinal fluid from ...

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    12. Prevalence of optical coherence tomography detected vitreomacular interface disorders: The Maastricht Study

      Prevalence of optical coherence tomography detected vitreomacular interface disorders: The Maastricht Study

      Purpose To calculate the prevalence of all vitreomacular interface (VMI) disorders and stratify according to age, sex and (pre)diabetes status. Methods The presence of VMI disorders was assessed in 2660 participants aged between 40 and 75 years from The Maastricht Study who had a gradable macular spectral-domain optical coherence tomography (SD-OCT) volume scan in at least one eye [mean 59.7 ± 8.2 years, 50.2% men, 1531 normal glucose metabolism (NGM), 401 prediabetes, 728 type 2 diabetes (DM2, oversampled)]. A stratified and multivariable logistic regression analysis was used. Results The prevalence of the different VMI disorders for individuals ...

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    13. Visualization of viscoelastic behavior in skin equivalent using optical coherence tomography-based straingraphy

      Visualization of viscoelastic behavior in skin equivalent using optical coherence tomography-based straingraphy

      Background/Purpose The relationships between the skin components and these mechanical roles are still unclear. To clarify these relationships, we investigated spatial mapping of the mechanical behavior of cultured skin equivalents (SEs) using optical coherence tomography (OCT)-based straingraphy. Methods We built a strain relaxation test system combined with OCT and developed an algorithm that could visualize a time-dependent strain distribution, named dynamic-optical coherence straingraphy (D-OCSA). Using this system, we analyzed how the spatial mechanical changes in the SEs depended on the culture duration. For quantitative analysis of viscoelastic behavior, we defined a relaxation attenuation coefficient of strain rate, which ...

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    14. Trimodal system for in vivo skin cancer screening with combined OCT-Raman and co-localized optoacoustic measurements

      Trimodal system for in vivo skin cancer screening with combined OCT-Raman and co-localized optoacoustic measurements

      A new multimodal system for rapid, noninvasive in vivo skin cancer screening is presented, combining optical coherence tomography (OCT) and optoacoustic (OA) modalities to provide precise tumor depth determination with a Raman spectroscopic modality capable of detecting the lesion type and, thus, providing diagnostic capability. Both optoacoustic and Raman setups use wide field skin illumination to ensure the compliance with Maximum Permissible Exposure (MPE) requirements. The Raman signal is collected via the OCT scanning lens to maximize the signal-to-noise ratio (SNR) of the measured signal while keeping radiation levels below MPE limits. OCT is used to optically determine the tumor ...

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    15. Prolonged in vivo functional assessment of the mouse oviduct using optical coherence tomography through a dorsal imaging window

      Prolonged in vivo functional assessment of the mouse oviduct using optical coherence tomography through a dorsal imaging window

      The oviduct (or fallopian tube) serves as an environment for gamete transport, fertilization, and preimplantation embryo development in mammals. Although there has been increasing evidence linking infertility with disrupted oviduct function, the specific roles that the oviduct plays in both normal and impaired reproductive processes remain unclear. The mouse is an important mammalian model to study human reproduction. However, most of the current analyses of the mouse oviduct rely on static histology or 2D visualization, and are unable to provide dynamic and volumetric characterization of this organ. The lack of imaging access prevents longitudinal live analysis of the oviduct and ...

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    16. Does spotty calcification attenuate the response of nonculprit plaque to statin therapy?: A serial optical coherence tomography study

      Does spotty calcification attenuate the response of nonculprit plaque to statin therapy?: A serial optical coherence tomography study

      Objectives The aim of this study was to determine if spotty calcification decreases the response of plaque progression to statin therapy. Background Previous studies showed that the presence of spotty calcification is a marker of vulnerable plaque. However, the relationship between spotty calcification and plaque progression is not clear. Methods Ninety-six nonculprit lipid-rich plaques in 69 patients who received serial optical coherence tomography (OCT) imaging were included. Plaques were divided into three groups: spotty calcification ( n = 38), calcified ( n = 12) and noncalcified ( n = 46) plaques. Spotty calcification was identified by the presence of a lesion <4 mm in length with ...

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    17. Changes in retina and choroid after haemodialysis assessed using optical coherence tomography angiography

      Changes in retina and choroid after haemodialysis assessed using optical coherence tomography angiography

      Background Reports of choroidal and retinal changes before and after haemodialysis are few and have been controversial. Traditional imaging modalities are insufficient for quantitative assessment. This study aims to use optical coherence tomography angiography to monitor the short-term vascular density and thickness changes in retina and choroid before and after haemodialysis. Methods Seventy-seven eyes of 77 patients with end-stage kidney disease undergoing haemodialysis were included. Ophthalmologic examinations including optical coherence tomography angiography were performed one hour before and after haemodialysis. The vascular density of retina and choroid were measured and calculated by optical coherence tomography angiography. The retinal thickness and ...

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      Mentions: Fudan University
    18. Choroidal thickness at age 66 years in the Danish high myopia study cohort 1948 compared with follow-up data on visual acuity over 40 years: a clinical update adding spectral domain optical coherence tomography

      Choroidal thickness at age 66 years in the Danish high myopia study cohort 1948 compared with follow-up data on visual acuity over 40 years: a clinical update adding spectral domain optical coherence tomography

      Background and purpose A population-based Copenhagen birth year 1948 cohort with high myopia recorded since age 14 years (spherical equivalent less than or equivalent to −6 D) has been followed over 50 years. Despite complications, current follow-ups have outlined a better visual prognosis than usually drawn from selected clinical series in the literature. For the present status at age 66 years, focus was on visual ability and choroidal thickness. Methods Twenty-eight of the original 39 participants were available in 2014. Medical history was updated. Best-corrected visual acuity (BCVA) data were compared with subfoveal choroidal thickness (SFCT), now measured by enhanced ...

      Read Full Article
    19. Optical coherence tomography angiography of normal skin and inflammatory dermatologic conditions

      Optical coherence tomography angiography of normal skin and inflammatory dermatologic conditions

      Background In clinical dermatology, the identification of subsurface vascular and structural features known to be associated with numerous cutaneous pathologies remains challenging without the use of invasive diagnostic tools. Objective To present an advanced optical coherence tomography angiography (OCTA) method to directly visualize capillary-level vascular and structural features within skin in vivo . Methods An advanced OCTA system with a 1310 nm wavelength was used to image the microvascular and structural features of various skin conditions. Subjects were enrolled and OCTA imaging was performed with a field of view of approximately 10 × 10 mm. Skin blood flow was identified using an ...

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    20. Automated detection of preserved photoreceptor on optical coherence tomography in choroideremia based on machine learning

      Automated detection of preserved photoreceptor on optical coherence tomography in choroideremia based on machine learning

      Optical coherence tomography (OCT) can demonstrate early deterioration of the photoreceptor integrity caused by inherited retinal degeneration diseases (IRD). A machine learning method based on random forests was developed to automatically detect continuous areas of preserved ellipsoid zone structure (an easily recognizable part of the photoreceptors on OCT) in sixteen eyes of patients with choroideremia (a type of IRD). Pseudopodial extensions protruding from the preserved ellipsoid zone areas are detected separately by a local active contour routine. The algorithm is implemented on en face images with minimum segmentation requirements, only needing delineation of the Bruch's membrane, thus evading the ...

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    21. Reflectance confocal microscopy and optical coherence tomography for the diagnosis of bullous pemphigoid and pemphigus and surrounding sub-clinical lesions

      Reflectance confocal microscopy and optical coherence tomography for the diagnosis of bullous pemphigoid and pemphigus and surrounding sub-clinical lesions

      Background Diagnosis of bullous pemphigoid (BP) and pemphigus is based on clinical features, histology, immunofluorescence and laboratory data. Objectives To evaluate features of BP and pemphigus at reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) in order to provide a rapid non-invasive bed-side diagnosis. Secondary objective was to evaluate the detectability of clinically non-visible lesions. Methods This was an observational, retrospective, multicentre study in which patients with suspicious lesions for BP or pemphigus underwent clinical assessment, RCM, OCT, blood tests and skin biopsy for histological and direct immunofluorescence examinations from January 2014 to December 2015. A total of 72 ...

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    49-72 of 849 « 1 2 3 4 5 6 ... 34 35 36 »
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