1. 745-768 of 839 « 1 2 ... 29 30 31 32 33 34 35 »
    1. Structural and functional outcomes after treatment of uveitic macular oedema: an optical coherence tomography and multifocal electroretinogram study

      Structural and functional outcomes after treatment of uveitic macular oedema: an optical coherence tomography and multifocal electroretinogram study
      Background:  The aim was to evaluate the correlation between the anatomical and functional outcomes before and after treatment of uveitic macular oedema. Methods:  Thirty-three eyes of 33 patients with uveitic macular oedema were included in the present study. Visual acuity (VA), optical coherence tomography (OCT) and multifocal electroretinogram (mfERG) were measured before and after treatment of the macular oedema. Correlation analyses between VA, OCT and mfERG parameters were performed. Results:  The VA and mfERG measurements showed statistically significant improvement after treatment of the macular oedema (p < 0.01) and OCT-measured central foveal thickness decreased significantly from 434 ± 135 µm before ...
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    2. Polypyrrole Nanoparticles: A Potential Optical Coherence Tomography Contrast Agent for Cancer Imaging

      Polypyrrole Nanoparticles: A Potential Optical Coherence Tomography Contrast Agent for Cancer Imaging

      A near-infrared (NIR) absorbing contrast agent based on polypyrrole nanoparticles is described. Quantitative optical coherence tomography studies on tissue phantoms and Mie scattering calculations indicate their potential application for early-stage cancer diagnosis.

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    3. Use of In Vivo Real-Time Optical Imaging for Esophageal Neoplasia

      Use of In Vivo Real-Time Optical Imaging for Esophageal Neoplasia
      Esophageal adenocarcinoma carries a poor prognosis, as it typically presents at a late stage. Thus, a major research priority is the development of novel diagnostic-imaging strategies that can detect neoplastic lesions earlier and more accurately than current techniques. Advances in optical imaging allow clinicians to obtain real-time histopathologic information with instant visualization of cellular architecture and the potential to identify neoplastic tissue. The various endoscopic imaging modalities for esophageal neoplasia can be grouped into 2 major categories: (1) wide-field imaging, a comparatively lower-resolution view for imaging larger surface areas, and (2) high-resolution imaging, which allows individual cells to be visualized ...
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    4. Confocal laser microscopy, optical coherence tomography and transonychial water loss for in vivo investigation of nails

      Confocal laser microscopy, optical coherence tomography and transonychial water loss for in vivo investigation of nails

      Background:  Nail disorders can be diagnostically challenging to the dermatologist. Non-invasive methods might help to avoid nail biopsies. More knowledge of the typical features of healthy nails with these techniques is needed for comparison with nail diseases.Objectives:  Objectives were to describe the typical morphology of healthy nails in optical coherence tomography (OCT) and confocal laser scanning microscopy (CLSM) and to examine the influence of exposure to water on OCT features, nail-thickness as well as on the transonychial water loss before and after a hand bath.Material and Methods:  In the first part healthy nail plates were investigated with OCT ...

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    5. Optical coherence tomography assessment of calcified plaque modification after rotational atherectomy

      Optical coherence tomography assessment of calcified plaque modification after rotational atherectomy

      Rotational atherectomy (RA) facilitates stent delivery in highly calcified coronary plaques (CCP). However, lesion ablation by RA in angulated segments may be affected by guidewire bias, leading to a non-uniform plaque modification. Intravascular optical coherence tomography (iOCT) is the highest resolution (∼10 μm axial) intravascular imaging modality available for clinical use; furthermore, near infrared light easily penetrates calcium, with significantly fewer artifacts, including no “blooming effect” as seen by intravascular ultrasound. Therefore, it may pose as a unique tool for serial calcium quantification, as related in this article with pre- and post-RA assessment, allowing accurate characterization of plaque modification, as ...

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    6. Application of optical coherence tomography in glaucoma suspect eyes

      Application of optical coherence tomography in glaucoma suspect eyes
      Purpose:  The aim of the study was to compare the optical coherence tomography (OCT) parameters of the optic nerve head (ONH) and retinal nerve fibre layer (RNFL) and to identify which measurements are best able to differentiate between normal and glaucoma suspect eyes. Methods:  The study included 27 eyes with ocular hypertension (OHT), 33 eyes with pre-perimetric glaucoma (PG), 30 perimetrically unaffected eyes of patients with glaucoma in the fellow eye (FE) and 58 eyes of age-matched normal volunteers. All subjects underwent a complete eye examination with standard automated perimetry, optic disc photography and OCT imaging. Peripapillary ‘fast RNFL thickness ...
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    7. Three-dimensional imaging of fibrous cap by frequency-domain optical coherence tomography

      Three-dimensional imaging of fibrous cap by frequency-domain optical coherence tomography

      Histopathological data correlated the presence of thin-cap fibroatheroma (TCFA) with adverse cardiovascular events. Intravascular optical coherence tomography (iOCT) is currently the only imaging modality with sufficiently high axial resolution (∼15µm) that allows direct fibrous-cap (FC) assessment in vivo. iOCT quantification of TCFA has been validated, but the assessment of a single cross-sectional image does not depict the complexity of the atherosclerotic plaque. We present two cases that illustrate the importance of three-dimensional volumetric quantification of the FC capitalizing on the properties of frequency-domain iOCT.

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    8. Barrett's esophagus: surveillance and reversal

      Barrett's esophagus: surveillance and reversal
      The following on surveillance and reversal of Barrett's esophagus (BE) includes commentaries on criteria for surveillance even when squamous epithelium stains normally with a variety of biomarkers; the long-term follow-up of surgery versus endoscopic ablation of BE; the recommended surveillance intervals in patients without dysplasia; the sampling problems related to anatomic changes following fundoplication; the value of tissue spectroscopy and optical coherence tomography; the cost-effectiveness of biopsy protocols for surveillance; the quality of life of Barrett's patients; and risk stratification and surveillance strategies.
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    9. Comparison of two artificial tear formulations for dry eye through high-resolution optical coherence tomography

      Comparison of two artificial tear formulations for dry eye through high-resolution optical coherence tomography
      Purpose:  The aim was to determine the efficacy of two artificial eye-drop formulations by analysing the lower tear film meniscus volume through a commercial high-resolution spectral-domain optical coherence tomographer. Methods:  Twenty dry eye patients (12 men, eight women, aged 57.5 ± 8.4 years) with refractive errors from -2.50 to +0.75 D (mean -1.34 ± 1.02 D) and cylinders lower than 1.00 D were examined. Tear meniscus volume was measured before, immediately after and 10, 30 and 60 minutes after instillation using the Copernicus high-resolution spectral-domain optical coherence tomographer (Optopol Tech SA, Zawiercie, Poland). Volume was ...
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    10. Noninvasive imaging of ethanol-induced developmental defects in zebrafish embryos using optical coherence tomography

      Noninvasive imaging of ethanol-induced developmental defects in zebrafish embryos using optical coherence tomography
      In this article, we report the use of optical coherence tomography for noninvasive cross-sectional real-time imaging of ethanol-induced developmental defects in zebrafish embryos larvae. For ethanol concentration of over 300 mM, developmental defects of eye (shrinkage and retinal abnormalities), malformation of the notochord and ataxia arising due to the toxic effects of ethanol were observed in OCT images from 3 days post fertilization onwards. The results suggest that OCT could be a valuable tool for noninvasive assessment of birth defects in small animal systems.
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    11. Evaluation of Neointimal Morphology of Lesions With or Without In-Stent Restenosis: An Optical Coherence Tomography Study

      Evaluation of Neointimal Morphology of Lesions With or Without In-Stent Restenosis: An Optical Coherence Tomography Study

      Background:Characterization of neointimal tissue is essential to understand the pathophysiology of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation. Using optical coherence tomography (OCT), we compared the morphologic characteristics of in-stent neointimal tissue from 33 ISR lesions with those of 192 non-ISR lesions after DES implantation.Hypothesis:We hypothesized that the morphologic characteristics of in-stent neointimal tissue from ISR lesions were different from those of non-ISR lesions after DES implantation.Methods:The DES were coated with sirolimus (n=52), paclitaxel (n=57), zotarolimus (n=84), or everolimus (n=32). In-stent restenosis was defined as ≥50% diameter stenosis at the ...

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    12. Using optical coherence tomography for the longitudinal non-invasive evaluation of epidermal thickness in a murine model of chronic skin inflammation

      Using optical coherence tomography for the longitudinal non-invasive evaluation of epidermal thickness in a murine model of chronic skin inflammation
      Background Non-invasive methods are desirable for longitudinal studies examining drug efficacy and disease resolution defined as decreases in epidermal thickness in mouse models of psoriasiform skin disease. This would eliminate the need for either sacrificing animals or collecting serial skin biopsies to evaluate changes in disease progression during an individual study. The quantitation of epidermal thickness using optical coherence tomography (OCT) provides an alternative to traditional histology techniques. Methods Using the KC-Tie2 doxycycline-repressible psoriasiform skin disease mouse model, OCT imaging was completed on diseased back skin of adult KC-Tie2 (n = 3–4) and control (n = 3–4) mice, followed immediately ...
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    13. Determination of spatial correlation functions of refractive index of living tissue

      Determination of spatial correlation functions of refractive index of living tissue

      We present what to our knowledge the first method of determination of spatial correlation functions of refractive index fluctuations of living tissues by Fourier domain optical coherence tomography (FDOCT). Based on the second-order statistical description of the random characteristic of living tissue, a formula which clearly relates the spectral electrical power from the detector to the Fourier spectrum of the refractive index correlation function is given. The method is characterized by its capability of noninvasive measurements in vivo. It has the potential of allowing quantitative discrimination between different tissue types or the same tissue at different pathological states by determining ...

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    14. Optical coherence tomography in retinal detachment cases

      Optical coherence tomography in retinal detachment cases
      Purpose To report the contribution of optical coherence tomography (OCT) in the assessment of macular pathology following retinal detachment surgery. Methods OCT imaging was employed to assess macular pathology following pars plana vitrectomy or scleral buckling for the management of retinal detachment cases. Results The presence of persistent subretinal fluid, cystoid macular oedema and the formation of epiretinal membranes or macular holes were demonstrated during optical coherence tomography imaging postoperatively. In the era of spectral domain OCT greater attention has also been directed in the evaluation of any alteration, and/or disruption of the junction line between photoreceptor inner and ...
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    15. Reproducibility of retinal thikness measurements in patients with age-related macular degeneration using fourier –domain optical coherence tomography

      Reproducibility of retinal thikness measurements in patients with age-related macular degeneration using fourier –domain optical coherence tomography
      Purpose To assess the reproducibility intraoperative macular thickness measurements using optical coherence tomography, spectral domain (spectralis, Heidelberg Engineering, Germany) in patients with wet AMD and to evaluate differences in reproducibility with optical coherence tomography (Stratus, Carl Zeiss Meditect Inc, USA). Methods prospective observational study and cross-sectional study included 30 eyes of 30 patients with exudative AMD. All of them were dealt with macular status by fast-track protocol posterior pole with spectral domain OCT (Spectralis OCT) and time domain OCT (Stratus OCT). Each patient underwent 3 consecutive scans each of the scanners and performed by the same observer to compare the ...
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    16. Relationship between time- and spectral-domain optical coherence tomography in glaucoma

      Relationship between time- and spectral-domain optical coherence tomography in glaucoma
      Purpose To evaluate the relationship of retinal nerve fiber layer (RNFL) thicknesses obtained with two different optical coherence tomography (OCT) systems, time-domain OCT (Stratus; Carl Zeiss Meditec, Dublin, Ca) and spectral-domain OCT (Cirrus; Carl Zeiss Meditec), in healthy and glaucomatous eyes. Methods Seventy healthy and 71 glaucoma individuals were prospective and consecutively selected. Only one eye per subject was included in the study. Glaucoma patients had intraocular pressure higher than 21 mmHg and abnormal standard automated perimetry (SAP). All participants underwent a comprehensive ophthalmic examination and at least 2 reliable SAPs. Peripapillary RNFL measurements were acquired with 2 different OCT ...
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    17. Abnormalities of optical coherence tomography and visual evoked potentials in patients with chiasmal compression syndrome

      Abnormalities of optical coherence tomography and visual evoked potentials in patients with chiasmal compression syndrome
      Purpose To report abnormalities of retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) and visual evoked potentials (VEP) in patients with compressive chiasmal tumors confirmed on MRI examination. Methods 22 eyes of 12 patients with parasellar tumors causing chiasmal compression syndrome were included to the study and compared to 59 eyes of 30 healthy patients. Exclusion criteria were any other ophthalmic or general condition that can affect both VEP and OCT measurements. All patients underwent MRI of the head to confirm the diagnosis, retinal nerve fiber thickness measurements with OCT and visual evoked potentials examination. Results ...
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    18. Parkinson´s disease and retinal optical coherence tomography

      Parkinson´s disease and retinal optical coherence tomography
      Purpose The aim of the study was to assess the retinal measurements and optic nerve head (ONH) morphology in patients with Parkinson's disease (PD) and to determine whether there is any correlation among these parameters and the disease´s duration. Methods Thirty patients affected by PD (mean age 67,3 ± 8,4; range: 49 - 83) were compared with 28 age-matched controls. In all subjects, peripapillary retinal nerve fiber layer (RNFL) thickness, ONH measurements, and macular thickness and volume were measured by optical coherence tomography (OCT). Results PD patients showed a statistically significant reduction of the overall peripapillary RNFL thickness ...
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    19. Evolution of autonomous and semi-autonomous robotic surgical systems: a review of the literature

      Evolution of autonomous and semi-autonomous robotic surgical systems: a review of the literature
      BACKGROUND: Autonomous control of surgical robotic platforms may offer enhancements such as higher precision, intelligent manoeuvres, tissue-damage avoidance, etc. Autonomous robotic systems in surgery are largely at the experimental level. However, they have also reached clinical application. METHODS: A literature review pertaining to commercial medical systems which incorporate autonomous and semi-autonomous features, as well as experimental work involving automation of various surgical procedures, is presented. Results are drawn from major databases, excluding papers not experimentally implemented on real robots. RESULTS: Our search yielded several experimental and clinical applications, describing progress in autonomous surgical manoeuvres, ultrasound guidance, optical coherence tomography guidance ...
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    20. Sirolimus-eluting stent fracture detection by three-dimensional optical coherence tomography

      Sirolimus-eluting stent fracture detection by three-dimensional optical coherence tomography

      Stent fracture has emerged as a complication of drug-eluting stent and is now recognized as contributing to in-stent restenosis and possibly stent thrombosis. Although optical coherence tomography (OCT) can detect stent fractures in the absence of circumference struts, it is challenging to visualize stent fractures with only cross-sectional OCT images. We describe two cases of restenosis with stent fracture detected by a novel 3-dimensional OCT image reconstruction technique. This technique allows identification of a single stent fracture even in the absence of angiographic signs.

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      Mentions: Takayuki Okamura
    21. Comparison of ex vivo optical coherence tomography with conventional frozen-section histology for visualizing basal cell carcinoma during Mohs micrographic surgery

      Comparison of ex vivo optical coherence tomography with conventional frozen-section histology for visualizing basal cell carcinoma during Mohs micrographic surgery
      Background  Mohs micrographic surgery offers high cure rates of nonmelanoma skin cancers with optimal sparing of normal tissue. However, it is generally more time-consuming and labour-intensive than traditional surgery. Optical coherence tomography (OCT) is an emergent technology that has the potential to diagnose basal cell carcinoma (BCC) in vivo.Objective  To compare the efficiency and accuracy of ex vivo OCT with frozen-section histology for identifying BCC in Mohs surgery.Methods  Thirty-eight patients were enrolled. After the stages were taken, images were captured with an OCT microscope and subsequently processed for standard frozen sections.Results  In total, 75 sections were scanned ...
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    22. A comparison of methods using optical coherence tomography to detect demineralized regions in teeth

      A comparison of methods using optical coherence tomography to detect demineralized regions in teeth
      Optical coherence tomography (OCT) is a three- dimensional optical imaging technique that can be used to identify areas of early caries formation in dental enamel. The OCT signal at 850 nm back-reflected from sound enamel is attenuated stronger than the signal back-reflected from demineralized regions. To quantify this observation, the OCT signal as a function of depth into the enamel (also known as the A-scan intensity), the histogram of the A-scan intensities and three summary parameters derived from the A-scan are defined and their diagnostic potential compared. A total of 754 OCT A-scans were analyzed. The three summary parameters derived ...
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