1. 1-24 of 255 1 2 3 4 ... 9 10 11 »
    1. Optical coherence tomography features of angiographic complex and smooth lesions in acute coronary syndromes

      Optical coherence tomography features of angiographic complex and smooth lesions in acute coronary syndromes

      Plaque rupture (PR) and superimposed thrombosis have been shown as the most frequent underlying substrate in acute coronary syndromes (ACS). Coronary angiography is a luminogram not able to define in vivo features of the culprit plaques. The aim of the study was to use optical coherence tomography (OCT) to investigate the pathology underlying complex (CL) and non-complex angiographic lesions (NCL). We retrospectively enrolled 107 ACS patients admitted to our institution; 83 with non-ST elevation ACS (NSTE-ACS) and 24 with ST-elevation myocardial infarction. Coronary angiography was performed and culprit lesions were classified according to Ambrose criteria into NCL (n = 47) and ...

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    2. Visualization of dynamic boiling processes using high-speed optical coherence tomography

      Visualization of dynamic boiling processes using high-speed optical coherence tomography

      Investigating microscale nucleate boiling processes with high heat flux requires experimental visualization and quantification with high spatial resolution in the micrometer range as well as a sufficient temporal resolution. Numerous measurement techniques are employed for providing comprehensive experimental data on microscale boiling processes and other multiphase flows. In this context, optical coherence tomography (OCT) has been introduced recently for the visualization of quasistatic growing vapor bubbles in turbid fluids with a high spatial resolution. Since OCT detects backscattered light, only one optical access is necessary and OCT is feasible for measurements in turbid media, where other imaging techniques fail. Within ...

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    3. Spectral domain optical coherence tomography imaging of mucopolysaccharidoses I, II, and VI A

      Spectral domain optical coherence tomography imaging of mucopolysaccharidoses I, II, and VI A

      Purpose The purpose of this study was to describe the spectral domain optical coherence tomography (SD-OCT) characteristics of patients with retinal manifestations of mucopolysaccharidoses (MPSs) I, II, and IV A. Design The research was a prospective, observational study. Methods Fourteen consecutive patients with variants of MPS and 15 healthy subjects underwent ophthalmic assessments including fundus examinations and SD-OCT. Results The fundus examinations revealed that four patients (two MPS I and two MPS II ) had pigmented retinopathy in both eyes. In addition, one MPS II patient had cystoid macular edema and two MPS II patients had abnormal disc morphology. SD-OCT revealed ...

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    4. Analysis of choroidal folds in acute Vogt–Koyanagi–Harada disease using high-penetration optical coherence tomography

      Analysis of choroidal folds in acute Vogt–Koyanagi–Harada disease using high-penetration optical coherence tomography

      Purpose To characterize patients with Vogt–Koyanagi–Harada (VKH) disease with choroidal folds (CFs) and determine how the foveal choroidal thickness changes after initial treatment using high-penetration optical coherence tomography (HP-OCT). Methods In this retrospective observational study, we analyzed 42 eyes of 21 patients with new-onset VKH disease to determine the demographic and clinical differences between patients with and without CFs. Results Twenty-four eyes (57.1 %) of 13 patients with VKH disease had CFs. The mean age ( p  = 0.0009) of patients with CFs was significantly higher than that of those without CFs (49.1 vs 39.4 years respectively ...

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    5. Current and evolving uses of optical coherence tomography in the genitourinary tract

      Current and evolving uses of optical coherence tomography in the genitourinary tract

      Optical coherence tomography is an emerging imaging modality that provides high-resolution, real-time, cross-sectional visualization of urologic tissue with promising results. Early studies have demonstrated detailed, accurate histologic information of tissues sampled. Optical coherence tomography (OCT) has also been applied in evaluating malignancy of the bladder, prostate, and kidney. In the bladder, it can assist in the identification, biopsy, and intraoperative resection of lesions suspicious for bladder cancer. Intraoperative use of OCT during radical prostatectomy can improve visualization of the neurovascular bundle and surgical margins. Several small, ex vivo studies have also shown promising results in the ability of OCT to ...

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    6. Fourier domain optical coherence tomography with ultralong depth range

      Fourier domain optical coherence tomography with ultralong depth range

      The depth ranges of typical implementations of Fourier domain optical coherence tomography (FDOCT), including spectral domain OCT (SDOCT) and swept source OCT (SSOCT), are limited to several millimeters. To extend the depth range of current OCT systems, two novel systems with ultralong depth range were developed in this study. One is the orthogonal dispersive SDOCT (OD-SDOCT), and the other is the recirculated swept source (R-SS) interferometer/OCT. No compromise between depth range and depth resolution is required in both systems. The developed OD-SDOCT system realized the longest depth range (over 100 mm) ever achieved by SDOCT, which is ready to ...

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    7. Electroretinography and optical coherence tomography reveal abnormal post-photoreceptoral activity and altered retinal lamination in patients with enhanced S-cone syndrome

      Electroretinography and optical coherence tomography reveal abnormal post-photoreceptoral activity and altered retinal lamination in patients with enhanced S-cone syndrome

      Purpose To compare functional abnormalities of enhanced S-cone syndrome ( ESCS ), as examined using standard and extended electroretinography (ERG), with structural findings and retinal architecture obtained by spectral domain optical coherence tomography (SD-OCT). Methods Four patients with ESCS underwent standard full-field and multifocal ERGs, with extended S-cone and ON/OFF ERG protocols also performed. SD-OCT was also carried out, and longitudinal reflectivity profiles (LRPs) were calculated for the perifoveolar retina. Results All four patients exhibited pathognomonic full-field ERG findings for ESCS , with delayed responses of similar waveforms to the same intensity flash under both scotopic and photopic conditions. The amplitudes of ...

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    8. The outer choroidoscleral boundary in full-thickness macular holes before and after surgery—a swept-source OCT stud

      The outer choroidoscleral boundary in full-thickness macular holes before and after surgery—a swept-source OCT stud

      Purpose To report on choroidal thickness and the morphology of the outer choroidoscleral boundary in swept-source OCT in patients with full-thickness macular holes (FTMH) before and after surgery. Methods Single center matched case–control study of 32 patients with FTMH (group 1), fellow eyes (group 2), and 32 eyes of 32 healthy controls (group 3). All eyes from group 1 had vitrectomy with a minimum follow-up of 3 months. Main outcome measures were the visibility and regularity of the outer choroidoscleral boundary (CSB), and additionally the eventual visibility of the suprachoroidal layer (SCL). Results Choroidal thickness was indifferent between groups ...

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    9. Failure analysis of adhesive restorations with SEM and OCT: from marginal gaps to restoration loss

      Failure analysis of adhesive restorations with SEM and OCT: from marginal gaps to restoration loss

      Objective The objective of this study was to analyse the failure mode of adhesive interfaces by comparing OCT and scanning electron microscope (SEM) analysis of class V restoration margins located on enamel and dentin. Materials and methods Three groups were tested that differed in the application of a 3-step etch-and-rinse adhesive system (OptiBond FL) prior to cavity filling with restorative composite resin (Clearfil AP-X). After tooth restoration and polishing, the samples were loaded in a fatigue machine, and adhesive interfaces were evaluated with OCT and SEM. Results Important and complementary information could be obtained with OCT analysis in respect to ...

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    10. Spectral-domain optical coherence tomographic features of choroidal neovascular membranes in multifocal choroiditis and punctate inner choroidopathy

      Spectral-domain optical coherence tomographic features of choroidal neovascular membranes in multifocal choroiditis and punctate inner choroidopathy

      Purpose To describe the spectral-domain optical coherence tomographic (SD-OCT) features of inflammatory choroidal neovascular membranes (iCNV) in multifocal choroiditis and punctate inner choroidopathy, and to compare them to those of the acute inflammatory lesions in the same underlying diseases. This is a retrospective, consecutive, observational case series. Methods Each patient underwent a comprehensive eye examination, fundus photography, and fluorescein angiography (FA) on the initial visit. SD-OCT features of iCNV were reviewed at presentation and 4 weeks later, and were compared to SD-OCT features of the inflammatory lesions. There were ten eyes with iCNV and eight eyes with the acute lesions ...

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    11. Assessment of vascular response after drug-eluting stents implantation in patients with diabetes mellitus: an optical coherence tomography sub-study of the J-DESsERT

      Assessment of vascular response after drug-eluting stents implantation in patients with diabetes mellitus: an optical coherence tomography sub-study of the J-DESsERT

      Even in the drug-eluting stent era, diabetes mellitus (DM) patients have high incidences of restenosis and repeat revascularization after percutaneous coronary intervention. The aim of this study was to compare vascular response after stent implantation between sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) by using optical coherence tomography (OCT) in DM patients as well as in non-DM patients. In the Japan-Drug Eluting Stents Evaluation; a Randomized Trial (J-DESsERT), the OCT sub-study enrolled 75 patients who underwent 8 months follow-up imaging after SES or PES implantation. Mean neointimal hyperplasia (NIH) thickness was significantly thinner in SES than PES in the DM ...

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    12. Structural and functional changes in glaucoma: comparing the two-flash multifocal electroretinogram to optical coherence tomography and visual field

      Structural and functional changes in glaucoma: comparing the two-flash multifocal electroretinogram to optical coherence tomography and visual field

      Purpose To correlate multifocal electroretinogram (mfERG) findings in the macular area of glaucoma patients with automated perimetry (visual fields) and with optical coherence tomography (OCT). Methods A two-global flash mfERG (VERIS™) was recorded in 20 eyes with primary open-angle glaucoma. The root mean square was calculated, and three response epochs were analysed: the direct component (15–45 ms) and two induced components (IC-1 at 45–75 ms and IC-2 at 75–105 ms). The central 10° of the mfERG was compared to the central 10° of the OCT and of the visual field. Responses grouped in a superior and in ...

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    13. Comparison of neointimal coverage and extra-stent lumen between sirolimus and everolimus-eluting stent using optical coherence tomography

      Comparison of neointimal coverage and extra-stent lumen between sirolimus and everolimus-eluting stent using optical coherence tomography

      The external lumen of a stent [defined as extra-stent lumen (ESL)] assessed by optical coherence tomography (OCT) may be related to the risk of thrombus formation after sirolimus-eluting stent (SES) implantation. An everolimus-eluting stent (EES) might provide relatively minimal inflammatory reaction and appropriate neointimal coverage. The purpose of this study was to compare the neointimal thickness and ESL between SES and EES. Patients who underwent OCT examination more than 7 months after either SES or EES implantation were enrolled. Stent area (SA), lumen area (LA), neointimal area (NIA) and neointimal thickness (NIT) of each strut were measured at 1-mm intervals ...

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      Mentions: Takayuki Okamura
    14. The effects of ocular magnification on Spectralis spectral domain optical coherence tomography scan length

      The effects of ocular magnification on Spectralis spectral domain optical coherence tomography scan length

      Purpose The purpose of this study was to assess the effects of incorporating individual ocular biometry measures of corneal curvature, refractive error, and axial length on scan length obtained using Spectralis spectral domain optical coherence tomography (SD-OCT). Methods Two SD-OCT scans were acquired for 50 eyes of 50 healthy participants, first using the Spectralis default keratometry (K) setting followed by incorporating individual mean-K values. Resulting scan lengths were compared to predicted scan lengths produced by image simulation software, based on individual ocular biometry measures including axial length. Results Axial length varied from 21.41 to 29.04 mm. Spectralis SD-OCT ...

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    15. Optical Coherence Tomography. ESASO Course Series Vol. 4 (Textbook)

      Optical Coherence Tomography. ESASO Course Series Vol. 4 (Textbook)

      The introduction of optical coherence tomography (OCT) into routine clinical practice has massively increased the amount and diversity of information regarding the living retina, and radically changed the understanding and management of almost every retinal disease. Producing an up-to-date book on OCT amid a high technological turnover and rapidly evolving concepts is a challenging task. The authors have succeeded in their mission by selecting certain common and controversial topics rather than attempting to be all-inclusive. This softcover book with 134 pages is a compilation of 15 articles co-authored by 40 contributors forming an international panel of well-respected experts. Each chapter ...

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    16. Wide-field spectral domain-optical coherence tomography in central serous chorioretinopathy

      Wide-field spectral domain-optical coherence tomography in central serous chorioretinopathy

      The aim the study was to describe wide-field spectral-domain optical coherence tomography morphologic relationships of the vitreous, retina, and choroid in central serous chorioretinopathy (CSCR) eyes. Standardized horizontal, vertical, and two oblique (supertemporal to inferonasal and supranasal to inferotemporal) SD-OCT sections were collected for 40 patient with CSCR. For extramacular imaging, images were obtained from eight locations: (1) nasal to the optic disk, (2) extreme nasal periphery, (3) superior to the superotemporal vascular arcade, (4) extreme superior periphery, (5) inferior to the inferotemporal vascular arcade, (6) extreme inferior periphery, (7) temporal to the macula, and (8) extreme temporal periphery. Wide-angle ...

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    17. Advanced Endoscopic Imaging in the Upper Gastrointestinal Tract (Book)

      Advanced Endoscopic Imaging in the Upper Gastrointestinal Tract (Book)

      Advanced endoscopic imaging incorporates several methods to enhance visualization of the upper gastrointestinal tract. It is an evolving field within advanced endoscopy and particularly important for the endoscopist performing ESD, as these modalities can aid all stages of ESD. Advanced imaging involves several different techniques, from chromoendoscopy (e.g. Lugol’s solution, methylene blue, indigo carmine), to optical enhancement methods (e.g. magnified endoscopy, narrow band imaging, confocal endomicroscopy) and electronic methods (e.g. spectrometry, optical coherence tomography). Frequently, a combination of techniques is utilized to maximize visualization of the lesion and surrounding mucosa. The endoscopist performing ESD needs to ...

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    18. Management of intrastromal glass foreign body based on anterior segment optical coherence tomography and Pentacam analysis

      Management of intrastromal glass foreign body based on anterior segment optical coherence tomography and Pentacam analysis

      We read with interest the article by Huda et al. [ 1 ] which reported the clinical aspects and the imaging of a patient with intrastromal glass foreign bodies after a road traffic accident using both anterior segment optical coherence tomography (AS-OCT) and ocular Pentacam, and “demonstrated that AS-OCT and ocular Pentacam are effective and necessary procedures for both the diagnosis and follow-up of intracorneal foreign bodies”. While this paper contributed to our understanding of how AS-OCT and ocular Pentacam may potentially affect the management protocol in these cases, there are relevant additions that we will like to highlight. We encountered a ...

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    19. Motion Artefact Correction in Retinal Optical Coherence Tomography Using Local Symmetry

      Motion Artefact Correction in Retinal Optical Coherence Tomography Using Local Symmetry

      Patient movements during the acquisition of SD-OCT scans create substantial motion artefacts in the volumetric data that hinder registration and 3D analysis and can be mistaken for pathologies. In this paper we propose a method to correct these artefacts using a single volume scan while still retaining the overall shape of the retina. The method was quantitatively validated using a set of synthetic SD-OCT volumes and qualitatively by a group of trained OCT grading experts on 100 SD-OCT scans. Furthermore, we compared the motion compensation estimation by the proposed method with a hardware eye tracker on 100 SD-OCT volumes.

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    20. Comparison of event-based analysis of glaucoma progression assessed subjectively on visual fields and retinal nerve fibre layer attenuation measured by optical coherence tomography

      Comparison of event-based analysis of glaucoma progression assessed subjectively on visual fields and retinal nerve fibre layer attenuation measured by optical coherence tomography

      The purpose is to study the ability of an event-based analysis of retinal nerve fibre layer (RNFL) attenuation measured by Stratus ® optical coherence tomography (OCT) and to detect progression across the spectrum of glaucoma. Adult glaucoma suspects, ocular hypertensives and glaucoma patients who had undergone baseline RNFL thickness measurement on Stratus OCT and reliable automated visual field examination by Humphrey’s visual field analyser prior to March 2007 and had 5-year follow-up data were recruited. Progression on OCT was defined by two criteria: decrease in average RNFL thickness from baseline by at least 10 and 20 µ. Visual field progression was ...

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    21. Three-dimensional optic nerve head images using optical coherence tomography with a broad bandwidth, femtosecond, and mode-locked laser

      Three-dimensional optic nerve head images using optical coherence tomography with a broad bandwidth, femtosecond, and mode-locked laser

      Purpose The aim of this study was to demonstrate the fine laminar structure of the optic nerve head (ONH), in vivo, using a broad wavelength, ultra-high resolution, and optically coherent tomography (OCT) system. Methods This high-resolution OCT system, based on a 200 nm bandwidth spectrometer and an 8 femtosecond ultra-short, mode-locked, coherent laser light source, enabled in vivo cross-sectional ONH imaging with 2.0 μm axial resolution. A total of 300 optic disc B-scans, which consisted of 300 × 2048 pixels, were obtained in 10 μm steps. Three-dimensional images were rendered from these images to obtain n face images of the ...

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    22. Effect of optical clearing agents on optical coherence tomography images of cervical epithelium

      Effect of optical clearing agents on optical coherence tomography images of cervical epithelium

      Optical coherence tomography (OCT) can be used as an adjunct to colposcopy in order to detect precancerous and cancerous cervical lesions. Optical clearing agents (OCAs) temporarily reduce the optical scattering of biological tissues. The purpose of this study was to investigate their influence on OCT imaging. OCT images were taken from unsuspicious and suspicious areas of fresh conization specimens immediately after resection and 5, 10, and 20 min after application of dimethyl sulfoxide ( DMSO ) or polyethylene glycol (PEG). Corresponding histologies were obtained from all sites. The images taken 5, 10, and 20 min after application of OCA were compared to ...

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    23. Evaluation of filtering blebs exhibiting transconjunctival oozing using anterior segment optical coherence tomography

      Evaluation of filtering blebs exhibiting transconjunctival oozing using anterior segment optical coherence tomography

      Purpose To explore the features of filtering blebs exhibiting transconjunctival oozing via three-dimensional anterior segment optical coherence tomography (3D AS-OCT). Methods In this cross-sectional study, 131 eyes of 131 patients exhibiting filtering blebs were examined. Of those, 20 eyes were excluded as flat-shaped, non-functioning bleb. Transconjunctival oozing was defined as transconjunctival aqueous egress evident on the bleb surface, in the absence of any point leak observable using a slit-lamp, as confirmed by application of digital pressure. Total bleb height, the height of the fluid-filled cavity, and bleb wall thickness and density were measured using 3D AS-OCT. Patient age, the etiology ...

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    24. Optical coherence tomography and electrophysiological findings in torpedo maculopathy

      Optical coherence tomography and electrophysiological findings in torpedo maculopathy

      Purpose To describe the morphofunctional findings in a 6-year-old child with a unilateral lesion of the temporal macula called “torpedo maculopathy” throughout a 1-year follow-up. Methods Evaluation of retinal morphology and function was assessed by means of spectral-domain OCT scans, best-corrected visual acuity, full-field flash electroretinogram (ERG), multifocal electroretinogram (mfERG) and pattern visual evoked potentials (VEP). Patient was examined every 4 months for a 1-year follow-up time. Results Torpedo maculopathy consisted in a sharply demarcated hypopigmented oval iuxta-macular lesion (1.5 DD wide × 0.7 DD high). The baseline visual acuity of the affected eye was 20/25. OCT showed ...

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