1. 1-24 of 406 1 2 3 4 ... 15 16 17 »
    1. Exploring choriocapillaris under reticular pseudodrusen using OCT-Angiography

      Exploring choriocapillaris under reticular pseudodrusen using OCT-Angiography

      Purpose To evaluate if choriocapillaris (CC) vessel density and CC decorrelation signal index are compromised in eyes with reticular pseudodrusen (RPD) using optical coherence tomography angiography (OCT-A). Methods Decorrelation values in OCT-A CC images of 20 RPD patients were measured in the outer superior and the outer inferior sector of the EDTRS grid and compared to age-matched healthy controls. CC vessel density and CC decorrelation signal index were measured within a 30 μm and a 10 μm OCT-A CC slab. CC data were correlated to number of RPD lesions, predominantly present RPD stage, predominantly present RPD type, retinal area affected ...

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    2. A case of unilateral circumscribed posterior keratoconus evaluated by three different imaging tools: optical coherence tomography, videokeratography, and Scheimpflug corneal tomography

      A case of unilateral circumscribed posterior keratoconus evaluated by three different imaging tools: optical coherence tomography, videokeratography, and Scheimpflug corneal tomography

      Posterior keratoconus is a rare corneal anomaly which is part of the ectatic corneal disorders. We report a clinical presentation of a unilateral posterior keratoconus in a 42-year-old man. At the time of presentation, corrected distance visual acuity (CDVA) was 20/20 with a correction of +2.50 +2.50 × 90° in the right eye and 20/40 with +1 +3.00 × 105° in the left eye. Slit lamp microscopy showed in the left eye an evidence of corneal thinning with a mild anterior protrusion and a remarkable posterior excavation. The intraocular pressure was 19 mmHg in right eye and ...

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    3. Optical coherence tomography measurements in compressive optic neuropathy associated with dysthyroid orbitopathy

      Optical coherence tomography measurements in compressive optic neuropathy associated with dysthyroid orbitopathy

      Background The purpose of the study was to assess the influence of optic nerve compression on the peripapillary retinal nerve fiber layer (RNFL) thickness in eyes with acute and chronic dysthyroid optic neuropathy (DON). Methods Patients with DON and healthy control subjects underwent peripapillary optical coherence tomography (OCT) scanning with the Cirrus HD-OCT. Patients were classified as acute (within 6 months from the onset of DON) versus chronic (6 months or more from the onset of DON) DON. The thickness of peripapillary RNFL was compared between eyes with acute and chronic DON and control eyes. Baseline factors associated with visual ...

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    4. Optical Coherence Tomography: Role in Percutaneous Coronary Intervention (Book Chapter)

      Optical Coherence Tomography: Role in Percutaneous Coronary Intervention (Book Chapter)

      Optical coherence tomography (OCT) is an imaging modality that utilizes back-reflection of near-infrared light. Superior resolution intra-coronary imaging, including assessment of plaque morphology and characteristics as well as imaging stents and post-stent complications have made OCT a powerful research tool, and more recently a clinical tool for guidance of PCI. Visualization of coronary lesions with OCT and their characterization as lipid-rich, fibrous, or fibro-calcific plaque can influence percutaneous coronary intervention (PCI) procedural planning. OCT has contributed significantly to the understanding of culprit lesion pathophysiology in acute coronary syndromes (ACS). ACS culprit lesions have been categorized by OCT features as resulting ...

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    5. Bright-Field Imaging and Optical Coherence Tomography of the Mouse Posterior Eye

      Bright-Field Imaging and Optical Coherence Tomography of the Mouse Posterior Eye

      Noninvasive live imaging has been used extensively for ocular phenotyping in mouse vision research. Bright-field imaging and optical coherence tomography (OCT) are two methods that are particularly useful for assessing the posterior mouse eye (fundus), including the retina, retinal pigment epithelium, and choroid, and are widely applied due to the commercial availability of sophisticated instruments and software. Here, we provide a guide to using these approaches with an emphasis on post-acquisition image processing using Fiji, a bundled version of the Java-based public domain software ImageJ. A bright-field fundus imaging protocol is described for acquisition of multi-frame videos, followed by image ...

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    6. Timing of retinal neuronal and axonal loss in MS: a longitudinal OCT study

      Timing of retinal neuronal and axonal loss in MS: a longitudinal OCT study

      The objective of the study was to investigate the timing of central nervous system tissue atrophy in MS by evaluating longitudinal retinal volume changes in a broadly representative cohort with disease duration across the entire arc of disease. In this longitudinal study, 135 patients with MS and 16 healthy reference subjects underwent spectral-domain optical coherence tomography (OCT) at baseline and 2 years later. Following OCT quality control, automated segmentation of the peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell–inner plexiform layer (mGCIPL) and macular inner nuclear layer (mINL) was performed. Generalized estimation equations were used to analyze longitudinal ...

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    7. Update on Intracoronary Optical Coherence Tomography: a Review of Current Concepts

      Update on Intracoronary Optical Coherence Tomography: a Review of Current Concepts

      Purpose of review The advent of intracoronary optical coherence tomography (OCT) has been a significant leap forward in the ability to visualize coronary structures with unprecedented resolution. However, the clinical application of this imaging modality has lagged behind rapid technological advances. One of the main reasons for the lack of wider clinical uptake has been the paucity of appropriately designed prospective randomized studies to demonstrate the impact of OCT on outcome measures after percutaneous coronary intervention (PCI). Recent findings Over the last couple of years, studies from large registries have shown the impact of OCT in decision-making in PCI, with ...

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    8. Depth-Resolved Full-Field Measurement of Corneal Deformation by Optical Coherence Tomography and Digital Volume Correlation

      Depth-Resolved Full-Field Measurement of Corneal Deformation by Optical Coherence Tomography and Digital Volume Correlation

      The study of vertebrate eye cornea is an interdisciplinary subject and the research on its mechanical properties has significant importance in ophthalmology. The measurement of depth-resolved 3D full-field deformation behaviour of cornea under changing intraocular pressure is a useful method to study the local corneal mechanical properties. In this work, optical coherence tomography was adopted to reconstruct the internal structure of a porcine cornea inflated from 15 to 18.75 mmHg (close to the physical porcine intraocular pressure) in the form of 3D image sequences. An effective method has been developed to correct the commonly seen refraction induced distortions in ...

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    9. Automatic assessment of time-resolved OCT images for selective retina therapy

      Automatic assessment of time-resolved OCT images for selective retina therapy

      Purpose In recent years, selective retina laser treatment (SRT), a sub-threshold therapy method, avoids widespread damage to all retinal layers by targeting only a few. While these methods facilitate faster healing, their lack of visual feedback during treatment represents a considerable shortcoming as induced lesions remain invisible with conventional imaging and make clinical use challenging. To overcome this, we present a new strategy to provide location-specific and contact-free automatic feedback of SRT laser applications. Methods We leverage time-resolved optical coherence tomography (OCT) to provide informative feedback to clinicians on outcomes of location-specific treatment. By coupling an OCT system to SRT ...

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    10. Correlation of the measurements of optical coherence tomography and diffuse tension imaging of optic pathways in amblyopia

      Correlation of the measurements of optical coherence tomography and diffuse tension imaging of optic pathways in amblyopia

      The aim of this study was to investigate whether a correlation exists between optical coherence tomography (OCT) of retina and diffusion tensor imaging (DTI) of the optic pathway measurements. All subjects underwent OCT measurements of optic nerve head, retinal nerve fiber layer, and macula. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of optic pathways were analyzed using DTI. Prechiasmatic FA values were significantly decreased in unilateral amblyopic group in both affected and sound fellow eyes ( p = 0.019 and 0.013), but not in bilateral amblyopic group ( p = 0.221) when compared with the control group. ADC values ...

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    11. Optical coherence tomography (OCT) prior to peroral endoscopic myotomy (POEM) reduces procedural time and bleeding: a multicenter international collaborative study

      Optical coherence tomography (OCT) prior to peroral endoscopic myotomy (POEM) reduces procedural time and bleeding: a multicenter international collaborative study

      Background Per-oral endoscopic myotomy (POEM) has emerged as an endoscopic treatment of achalasia. There are no pre-procedural imaging modalities to predict the safest and the most efficacious approach. Aim To evaluate the use of optimal coherence tomography (OCT) in providing a pre-procedural esophageal assessment. Methods Patients undergoing POEM from July 2013 to November 2015 were captured in a multicenter, international registry. Patients who underwent OCT pre-POEM (“OCT arm”) were compared to patients without pre-POEM OCT (“control arm”). OCT images were assessed for the degree of vascularity and the thickness of the circular muscular layer, and an approach was determined. Results ...

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    12. Diabetic retinal pigment epitheliopathy: fundus autofluorescence and spectral-domain optical coherence tomography findings

      Diabetic retinal pigment epitheliopathy: fundus autofluorescence and spectral-domain optical coherence tomography findings

      Purpose To describe the characteristics of an unfamiliar disease entity, diabetic retinal pigment epitheliopathy (DRPE), using fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT). Methods This retrospective study included 17 eyes from 10 proliferative diabetic retinopathy (PDR) patients with granular hypo-autofluorescence and/or variable hyper-autofluorescence on FAF (DRPE group) and 17 eyes from 10 age- and sex-matched PDR patients without abnormal autofluorescence (PDR group). Eyes with diabetic macular edema were excluded. Visual acuity (VA), retinal thickness (RT), and choroidal thickness (CT) were compared between the groups. Results Eyes in the DRPE group had worse logMAR VA than eyes in ...

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    13. A honeycomb-like structure in the left anterior descending coronary artery treated using a scoring device and drug-eluting stent implantation: a case report

      A honeycomb-like structure in the left anterior descending coronary artery treated using a scoring device and drug-eluting stent implantation: a case report

      Background A honeycomb-like structure in the coronary artery is rarely diagnosed by intracoronary ultrasound or optical coherence tomography. Further, its structural mechanisms and response to interventional therapy remain unknown. Case presentation A 59-year-old Japanese man was referred to our hospital because of acute decompensated heart failure with rapid atrial fibrillation. After receiving anticoagulant therapy, a coronary angiogram revealed a braid-like appearance and an intracoronary ultrasound image confirmed a honeycomb-like structure in the mid left anterior descending coronary artery. We inserted two guide wires into different partitions. Although a balloon angioplasty with a scoring device could not completely fenestrate these partitions ...

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    14. OCT in Central Nervous System Disease: The Eye as a Window to the Brain (Textbook)

      OCT in Central Nervous System Disease: The Eye as a Window to the Brain (Textbook)

      This book reviews recent important advances in the use of optical coherence tomography (OCT) in order to analyze neurodegeneration within the retina through the quantification of axonal loss. Detailed information is provided on the role of OCT as a promising tool for the evaluation of disease progression in numerous neurodegenerative disorders and as a biological marker of neuroaxonal injury. The disorders considered include multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, intracranial hypertension, Friedreich’s ataxia, schizophrenia, hereditary optic neuropathies, glaucoma, and amblyopia. Individual chapters are also devoted to OCT technique, new OCT technology in neuro-ophthalmology, OCT and pharmacological treatment ...

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    15. Associations between preoperative OCT parameters and visual outcome 3 months postoperatively in patients undergoing vitrectomy for idiopathic epiretinal membrane

      Associations between preoperative OCT parameters and visual outcome 3 months postoperatively in patients undergoing vitrectomy for idiopathic epiretinal membrane

      Purpose To evaluate the effect of preoperative optical coherence tomography (OCT) features on postoperative visual acuity and change in acuity after epiretinal membrane (ERM) surgery. Methods This was a retrospective consecutive case series of patients with symptomatic idiopathic ERMs who underwent vitrectomy and membrane peel between 2008 and 2013. The main outcomes were postoperative letter score and change in letter score. The association between visual acuity and OCT features was estimated using linear regression, correcting for important baseline covariates. OCT features included central foveal thickness, maximum retinal thickness, retinal cross-sectional area, central photoreceptor thickness, central epiretinal membrane, intraretinal cyst presence ...

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    16. Optical Coherence Tomography in Grafts (Book Chapter)

      Optical Coherence Tomography in Grafts (Book Chapter)

      Coronary artery bypass graft (CABG) is a commonly used surgery to treat patients with complex artery disease. Long-term outcome of specifically saphenous vein grafts (SVG) is considered unfavorable, while it is the most commonly used conduit. The SVG is prone to occlude and half of the patients will develop vein graft failure (VGF) within 10 years. VGF is the result of the accelerated atherosclerosis that differs from what is seen in native coronaries. Revascularization of SVGs is considered challenging, due to their challenging anatomy and embolic nature. Optical coherence tomography (OCT) imaging is an invasive imaging technique that can be ...

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    17. Identification of anterior chamber angle parameters with a portable SD-OCT device compared to a non-portable SD-OCT

      Identification of anterior chamber angle parameters with a portable SD-OCT device compared to a non-portable SD-OCT

      The aim of this study is to compare a portable spectral domain optical coherence tomography (SD-OCT) device with a non-portable SD-OCT for the identification of anterior chamber angle parameters based on location of Schwalbe’s line (SL) and to measure their reproducibility. 99 eyes from 46 normal, healthy participants underwent imaging of the inferior iridocorneal angle with the iVue and Cirrus SD-OCT under well-controlled low-light conditions. SL-angle opening distance (SL-AOD) and SL-trabecular iris space area (SL-TISA) were measured by masked, certified graders at the Doheny Image Reading Center using customized Image J grading software. Inter- and intrainstrument, as well as ...

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    18. Development of in vivo tissue-engineered microvascular grafts with an ultra small diameter of 0.6 mm (MicroBiotubes): acute phase evaluation by optical coherence tomography and magnetic resonance angiography

      Development of in vivo tissue-engineered microvascular grafts with an ultra small diameter of 0.6 mm (MicroBiotubes): acute phase evaluation by optical coherence tomography and magnetic resonance angiography

      Biotubes, i.e., in vivo tissue-engineered connective tubular tissues, are known to be effective as vascular replacement grafts with a diameter greater than several millimeters. However, the performance of biotubes with smaller diameters is less clear. In this study, MicroBiotubes with diameters <1 mm were prepared, and their patency was evaluated noninvasively by optical coherence tomography (OCT) and magnetic resonance angiography (MRA). MicroBiotube molds, containing seven stainless wires (diameter 0.5 mm) covered with silicone tubes (outer diameter 0.6 mm) per mold, were embedded into the dorsal subcutaneous pouches of rats. After 2 months, the molds were harvested with ...

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    19. Optical Coherence Tomography as Glucose Sensor in Blood

      Optical Coherence Tomography as Glucose Sensor in Blood

      Optical coherence tomography is a modern imaging modality that can visualize the biological tissues on micron levels. This chapter describes the use of OCT technique for measuring glucose in liquid phantoms, whole blood (in vitro and in vivo) based on temporal dynamics of light scattering. Whole blood smears imaged with microscope reveal the effect of red blood cells deformation and aggregation with white light microscope for animal and human blood. We found the changes in the shape of individual cells from biconcave discs to spherical shapes and eventually the lysis of the cells at optimum concentration of glucose. The increase ...

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    20. Evaluation of choroidal thickness in psoriasis using optical coherence tomography

      Evaluation of choroidal thickness in psoriasis using optical coherence tomography

      The purpose of this study was to evaluate choroidal thickness (CT) in patients with psoriasis using enhanced depth imaging optical coherence tomography (EDI-OCT) and to determine its relationship with psoriasis activity indices. In this prospective study, EDI-OCT images were obtained in consecutive patients with psoriasis and in age–gender-matched healthy individuals. Comprehensive ophthalmic examination and EDI-OCT evaluation were performed. CT was measured in the subfoveal area. Correlation analyses were performed to identify the relationship of the CT with disease duration and clinical disease activity score. In total, 65 individuals were evaluated in this study, 35 with psoriasis and 30 controls ...

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    21. New insights into spotty calcification and plaque rupture in acute coronary syndrome: an optical coherence tomography study

      New insights into spotty calcification and plaque rupture in acute coronary syndrome: an optical coherence tomography study

      Although recent optical coherence tomography (OCT) studies have focused on spotty calcification, whether there were any characteristics in the concomitant existence of calcification and plaque rupture remains unknown. The aim of the present study was to investigate the characteristics of spotty calcification in acute coronary syndrome (ACS) patients with or without plaque rupture, using OCT. This study enrolled 98 consecutive patients with ACS. OCT image acquisitions were performed in the culprit lesions, and patients were divided into the plaque rupture group ( n = 38) and the non-rupture group ( n = 60). The frequency of spotty calcification ( p = 0.006), thin-capped fibroatheroma ( p ...

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    22. Usefulness of rotational atherectomy with optical frequency domain imaging guidance for severe calcified coronary lesions after Kawasaki disease

      Usefulness of rotational atherectomy with optical frequency domain imaging guidance for severe calcified coronary lesions after Kawasaki disease

      A 40-year-old man was referred to our hospital for the treatment of severe calcified coronary lesions of right coronary artery due to Kawasaki disease. He had a past history of early stent thrombosis after drug-eluting stent implantation for acute myocardial infarction at the left anterior descending artery, regardless of continued dual antiplatelet therapy and no stent malapposition and underexpansion. We performed rotational atherectomy and plain balloon angioplasty with optical frequency domain imaging guidance, and obtained an excellent initial result without stent implantation, which was maintained during the 1-year follow-up.

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    1-24 of 406 1 2 3 4 ... 15 16 17 »
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