1. 721-744 of 903 « 1 2 ... 28 29 30 31 32 33 34 ... 36 37 38 »
    1. Spectral optical coherence tomography findings in patients with ocular toxoplasmosis and active satellite lesions (MINAS Report 1)

      Spectral optical coherence tomography findings in patients with ocular toxoplasmosis and active satellite lesions (MINAS Report 1)

      Purpose:  To characterize the active retinochoroiditis lesion observed in patients with the classic clinical presentation of ocular toxoplasmosis (OT) utilizing spectral optical coherence tomography (SOCT). Methods:  Twenty-four patients with OT and satellite lesions underwent standardized ophthalmologic examination and multimodal fundus imaging. The SOCT findings observed at presentation were described. Results:  The mean age of the fourteen (58.3%) women and ten (41.7%) men was 27.6 years. The mean LogMAR ETDRS best-corrected visual acuity was 0.58 (Snellen equivalent, 20/80+1). On SOCT evaluation, the posterior hyaloid was diffusely thickened in 23 (95.8%) of 24 eyes, increased ...

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    2. Evaluation of zebrafish brain development using optical coherence tomography

      Evaluation of zebrafish brain development using optical coherence tomography

      The zebrafish is a well-established model system used to study and understand various human biological processes. The present study used OCT to investigate growth of the adult zebrafish brain. Twenty zebrafish were studied, using their standard lengths as indicators of their age. Zebrafish brain aging was evaluated by analyzing signal attenuation rates and texture features in regions of interest (ROIs). Optical scattering originates from light interaction with biological structures. During development, the zebrafish brain gains cells. Signal attenuation rate, therefore, increases with increasing zebrafish brain age. This study's analyses of texture features could not identify aging in zebrafish brain ...

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    3. Comparison of EyeCam and anterior segment optical coherence tomography in detecting angle closure

      Comparison of EyeCam and anterior segment optical coherence tomography in detecting angle closure

      Purpose:  To compare the diagnostic performance of EyeCam (Clarity Medical Systems, Pleasanton, CA, USA) and anterior segment optical coherence tomography (ASOCT, Visante; Carl Zeiss Meditec, Dublin, CA, USA) in detecting angle closure, using gonioscopy as the reference standard. Methods:  Ninety-eight phakic patients, recruited from a glaucoma clinic, underwent gonioscopy by a single examiner, and EyeCam and ASOCT imaging by another examiner. Another observer, masked to gonioscopy findings, graded EyeCam and ASOCT images. For both gonioscopy and EyeCam, a closed angle in a particular quadrant was defined if the posterior trabecular meshwork was not visible. For ASOCT, angle closure was defined ...

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    4. Intracoronary imaging of coronary fibromuscular dysplasia with OCT and IVUS

      Intracoronary imaging of coronary fibromuscular dysplasia with OCT and IVUS

      Fibromuscular dysplasia (FMD) is a segmental non-atherosclerotic, non-inflammatory vasculopathy typically of small-medium muscular arteries. Coronary FMD (CFMD) is believed to be rare. However, we have found an association between spontaneous coronary artery dissection (SCAD) and FMD as the cause of myocardial infarction in ∼25% of young women age <50. It is plausible that preexisting CFMD predisposed these women to SCAD. Definitive diagnosis of CFMD entails autopsy that is obviously impractical, and prior angiographic description does not differentiate superimposed SCAD from obliterative arteriopathy of CFMD. Adjunctive intravascular ultrasound or optical coherence tomography may aid the diagnosis of CFMD and we report ...

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    5. High-definition optical coherence tomography enables visualization of individual cells in healthy skin: comparison to reflectance confocal microscopy

      High-definition optical coherence tomography enables visualization of individual cells in healthy skin: comparison to reflectance confocal microscopy

      High-definition OCT (HD-OCT) is an innovative technique based on the principle of conventional OCT. Our objective was to test the resolution and image quality of HD-OCT in comparison with reflectance confocal microscopy (RCM) of healthy skin. Firstly, images have been made of a ultra-high-resolution line-pair phantome with both systems. Secondly, we investigated 21 healthy volunteers of different phototypes with HD-OCT and RCM on volar forearm and compared the generated images. HD-OCT displays also differences depending on the skin phototype and anatomical site. The 3-μm lateral resolution of the HD-OCT could be confirmed by the phantom analysis. The identification of ...

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    6. Automatic scanning of large tissue areas in neurosurgery using optical coherence tomography

      Automatic scanning of large tissue areas in neurosurgery using optical coherence tomography

      Background With its high spatial and temporal resolution, optical coherence tomography (OCT) is an ideal modality for intra-operative imaging. One possible application is to detect tumour invaded tissue in neurosurgery, e.g. during complete resection of glioblastoma. Ideally, the whole resection cavity is scanned. However, OCT is limited to a small field of view (FOV) and scanning perpendicular to the tissue surface. Methods We present a new method to use OCT for scanning of the resection cavity during neurosurgical resection of brain tumours. The main challenges are creating a map of the cavity, scanning perpendicular to the surface and merging ...

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    7. Spectral domain optical coherence tomography and in vivo confocal microscopy imaging of a case of Bietti's crystalline dystrophy

      Spectral domain optical coherence tomography and in vivo confocal microscopy imaging of a case of Bietti's crystalline dystrophy

      Background The aim was to describe the morphology and localisation of crystals in a case of Bietti's crystalline corneo-retinal dystrophy (BCD) by means of spectral domain optical coherence tomography (SD-OCT) and in vivo confocal microscopy (IVCM). Methods Clinical examination, SD-OCT and IVCM evaluation of a 35-year-old woman with BCD. Results Optical coherence tomography examination of the macular region revealed multiple crystals in the retinal pigment epithelium (RPE)-choriocapillaris, some crystals within the full thickness of the neurosensory retina and less numerous crystals in the choroid. Crystals were present peripherally in areas of retinal atrophy, predominantly in the choroid and ...

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    8. Correlation of temperature rise and optical coherence tomography characteristics in patient retinal photocoagulation

      Correlation of temperature rise and optical coherence tomography characteristics in patient retinal photocoagulation

      We conducted a study to correlate the retinal temperature rise during photocoagulation to the afterward detected tissue effect in optical coherence tomography (OCT). 504 photocoagulation lesions were examined in 20 patients. The retinal temperature increase was determined in real-time during treatment based on thermoelastic tissue expansion which was probed by repetitively applied ns laser pulses. The tissue effect was examined on fundus images and OCT images of individualized lesions. We discerned seven characteristic morphological OCT lesion classes. Their validity was confirmed by increasing visibility and diameters. Mean peak temperatures at the end of irradiation ranged from approx. 60 °C to ...

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    9. Superficial wounding model for epidermal barrier repair studies: Comparison of Erbium:YAG laser and the suction blister method

      Superficial wounding model for epidermal barrier repair studies: Comparison of Erbium:YAG laser and the suction blister method

      Background and Objectives Wound-healing studies use mainly mechanical methods for wound induction, which are laborious and difficult to standardize. Objective of this study was to evaluate the Erbium:Yttrium-Aluminium-Garnet (Er:YAG) laser method as a model of epidermis ablation on human skin in vivo and to compare the quality and healing rates of Er:YAG laser and suction blister (SB) wounds. Materials and Methods Er:YAG laser and SB wounds were made on the forearms of 10 healthy volunteers. Post-wounding measurements including wound surface area (WSA) from photographs, wound depth from 3D volume analysis, trans-epidermal water loss (TEWL), laser doppler ...

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    10. Imaging of basal cell carcinoma by high-definition optical coherence tomography. Histomorphologic correlation a pilot study

      Imaging of basal cell carcinoma by high-definition optical coherence tomography. Histomorphologic correlation a pilot study

      Background:  With the continued development of non-invasive therapies for BCC such as PDT and immune therapies, the non-invasive diagnosis and monitoring become increasingly relevant. High-definition optical coherence tomography is a high-resolution imaging tool, with micrometer resolution in both transversal and axial directions, enable to visualize individual cells up to a depth of around 570 μm filling the imaging gap between conventional optical coherence tomography and reflectance confocal microscopy. Objective:  We sought to determine the feasibility of detecting basal cell carcinoma by this technique using criteria defined for reflectance confocal microscopy and conventional optical coherence tomography and compared to histology. Method ...

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    11. Actinic keratosis in the en-face and slice imaging mode of high definition optical coherence tomography and comparison with histology

      Actinic keratosis in the en-face and slice imaging mode of high definition optical coherence tomography and comparison with histology

      Optical coherence tomography (OCT) allows real-time, in vivo examination of non-melanoma skin cancer. An innovative high-definition (HD)-OCT with a horizontal (en-face) and vertical (slice) imaging mode offers additional information in the diagnosis of actinic keratosis (AK) and may potentially replace invasive diagnostic biopsies. Objectives:  To define the characteristic morphologic features of AK by using HD-OCT in the two imaging modes compared to histopathology as gold standard. Methods:  A total of 20 AKs were examined by HD-OCT in the en-face and slice imaging mode and characteristic features were described and evaluated in comparison to the histopathological findings. Furthermore, the HD-OCT ...

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    12. Hair shaft abnormalities after chemotherapy and tamoxifen therapy in breast cancer patients evaluated by optical coherence tomography

      Hair shaft abnormalities after chemotherapy and tamoxifen therapy in breast cancer patients evaluated by optical coherence tomography

      Background:  Antineoplastic treatment for breast cancer is frequently associated with alopecia. Increasingly, changes in texture and shape of regrowing hair after chemotherapy have been reported, without evaluation on a scientific basis. Optical coherence tomography (OCT) provides highly reproducible measurements of hair shaft parameters. Objectives:  This study aims at evaluating hair shaft alterations using OCT in chemotherapy-induced alopecia and in patients taking tamoxifen. Methods:  The measurements of this prospective case series were performed on women, aged 29–68 years, receiving either tamoxifen (n = 17) or chemotherapy (n = 17) prior to (T1) and after (T2) treatment. Each time, 20 hairs from 2 ...

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    13. Spectral domain optical coherence tomography finding in posterior microphthalmos

      Spectral domain optical coherence tomography finding in posterior microphthalmos

      An eight-year-old boy presented with decreased vision in both eyes. At presentation, the visual acuity was 6/60 in both eyes with high plus spheres. Anterior segment examination was normal. Fundus examination and spectral domain optical coherence tomography were consistent with posterior microphthalmos and showed an elevated foveal contour and fold in the outer plexiform layer. External limiting membrane, photoreceptor and retinal pigment epithelium were not involved in the fold. To the best of our knowledge this is the first such case report with optical coherence tomography imaging of the retinal layer involved in a case of posterior microphthalmos.

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    14. Comparison of retinal nerve fiber layer thickness measurements by spectral-domain optical coherence tomography systems using a phantom eye model

      Comparison of retinal nerve fiber layer thickness measurements by spectral-domain optical coherence tomography systems using a phantom eye model

      To quantify differences in nerve fiber layer thickness measurements by various spectral-domain optical coherence tomography (SD-OCT) systems, we developed a phantom eye model. We tested twelve SD-OCT systems of four manufacturers. All systems combined overestimated the 49 µm thick phantom RNFL thickness on average by 18 µm. Within brands, thickness measurements differed statistically significant for one Topcon, one RTVue and one Cirrus. Between brands, thickness determined with RTVue and Topcon differed statistically significant from Cirrus and Spectralis. The maximum difference between mean thicknesses is 3.6 µm within brands and 7.7 µm between brands.

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    15. Multimodality intracoronary imaging in spontaneous coronary artery dissection: Impacts of intravascular ultrasound, optical coherence tomography, and coronary angioscopy

      Multimodality intracoronary imaging in spontaneous coronary artery dissection: Impacts of intravascular ultrasound, optical coherence tomography, and coronary angioscopy

      Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and its etiology and pathogenesis have not been well understood. Intracoronary imaging modalities with intravascular ultrasound and optical coherence tomography would enable a precise diagnosis in this entity. Coronary angioscopy is also a unique tool for allowing direct visualization of the luminal surface of a vessel. We described an interesting case of SCAD documented with multimodality intracoronary imaging showing the presence of superficial lipid plaque nearby the coronary dissection entry point, which might have been associated with fragility of the arterial wall and the subsequent development of ...

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    16. Optical coherence tomography for the evaluation of retinal and optic nerve morphology in animal subjects: practical considerations

      Optical coherence tomography for the evaluation of retinal and optic nerve morphology in animal subjects: practical considerations

      Optical coherence tomography (OCT) is a noninvasive, noncontact imaging technique capable of producing high-resolution images of the retina and optic nerve. These images provide information that is useful for following the progression and/or resolution of posterior segment disease. Rapid advances in OCT technology allow the acquisition of increasingly detailed images, approaching the original goal of providing in vivo histopathology. Increases in scan acquisition speeds and axial resolution enhance the clinical diagnostic value of this modality. Adapting instrumentation designed for use in human patients for use in animals can be challenging. Each species has a unique set of adjustments that ...

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    17. Noninvasive clinical assessment of port-wine stain birthmarks using current and future optical imaging technology: A review

      Noninvasive clinical assessment of port-wine stain birthmarks using current and future optical imaging technology: A review

      Port wine stain (PWS) birthmarks are one class of benign congenital vascular malformation. Laser therapy is the most successful treatment modality of PWS. Unfortunately, this approach has limited efficacy, with only 10% of patients experiencing complete blanching of the PWS. To address this problem, several research groups have developed technologies and methods designed to study treatment outcome and improve treatment efficacy. This paper reviews seven optical imaging techniques currently in use or under development to assess treatment efficacy, focusing on: Reflectance spectrophotometers/tristimulus colorimeters, Laser Doppler flowmetry (LDF) and Laser Doppler imaging (LDI), Cross-polarized diffuse reflectance color imaging system (CDR ...

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    18. Effects of age and disc area on optical coherence tomography measurements and analysis of correlations between optic nerve head and retinal nerve fibre layer

      Effects of age and disc area on optical coherence tomography measurements and analysis of correlations between optic nerve head and retinal nerve fibre layer

      ACKGROUND:The aim here was to investigate whether optic nerve head (ONH) parameters or retinal nerve fibre layer (RNFL) thickness correlate with age or disc area and whether the neuroretinal rim correlates with RNFL thickness. METHODS: This cross-sectional study enrolled 133 healthy subjects and analysed one randomly selected eye of each subject. All measurements of ONH parameters (including neuroretinal rim, disc and cup areas and cup-to-disc ratios) and RNFL thickness (global and quadrants) were taken by a single experienced operator using optical coherence tomography (OCT). RESULTS: Of the rim parameters analysed, average nerve width (the height of the nerve fibre ...

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    19. Diagnosis and interventions for central serous chorioretinopathy: review and update

      Diagnosis and interventions for central serous chorioretinopathy: review and update

      Most acute cases of central serous chorioretinopathy resolve spontaneously with minimal visual impairment. The small percentage of eyes developing chronic or recurrent disease that do warrant treatment are often difficult to control. Emergent investigations and treatments have added to the established options available to manage these cases. Optical coherence tomography has proved valuable for both imaging subtle fundoscopic findings and monitoring disease progression. Fluorescein angiography aids identification of pigment epithelial leaks, and targets the use of argon laser treatment if outside the fovea. Fluorescein angiography also assists differentiation from other choroidal pathologies such as choroidal neovascularisation and polypoidal choroidal vasculopathy ...

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    20. Spectral domain optical coherence tomography and angiographic findings in multifocal posterior pigment epitheliopathy treated with low-fluence photodynamic therapy

      Spectral domain optical coherence tomography and angiographic findings in multifocal posterior pigment epitheliopathy treated with low-fluence photodynamic therapy

      Purpose The aim was to evaluate spectral domain optical coherence tomographic (SD-OCT), fluorescein angiography (FA) and indocyanine green angiography (ICGA) findings in multifocal posterior pigment epitheliopathy (MPPE) treated with low-fluence photodynamic therapy. Methods A 54-year-old Japanese man with serous retinal detachment (SRD) and pigment epithelial detachment (PED) due to multifocal posterior pigment epitheliopathy in the right eye was managed with ICGA-guided low-fluence photodynamic therapy. Outcome measures included visual acuity, SD-OCT appearance and FA and ICGA findings. Results The patient received low-fluence photodynamic therapy within two weeks after the onset of symptoms. After treatment, serous retinal detachment and PED resolved in ...

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    21. Evaluation of oral mucosa collagen condition with cross-polarization optical coherence tomography

      Evaluation of oral mucosa collagen condition with cross-polarization optical coherence tomography

      The goal of the research was analysis of the effect of collagen condition in formation of cross-polarized CP OCT images. We used of the CP OCT technique for studying collagen condition on an example of oral mucosa. Special histologic picrosirius red (PSR) staining of cheek mucosa specimens was used with subsequent assessing of the result of collagen staining in polarized light. High correlation (r = 0.692, p = 0.0001) between OCT signal standard deviation (SD) in cross-polarized images and brightness of PSR stained collagen fibers in cheek mucosa specimens was demonstrated in patients with inflammatory intestine and oral mucosa diseases ...

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    22. Macular thickness and volume of myopic eyes measured using spectral-domain optical coherence tomography

      Macular thickness and volume of myopic eyes measured using spectral-domain optical coherence tomography

      Purpose:  The aim was to evaluate macular thickness and volume of young myopic eyes measured using Cirrus HD spectral-domain optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA). Methods:  Three hundred and thirty-six eyes of 336 healthy young subjects (aged 19 to 25) with various degrees of refractive error and axial length were recruited. Average macular thickness, foveal thickness, inner/outer macular thickness and macular volume were measured using Cirrus HD-OCT. The association between refractive error/axial length and retinal thickness/volume was analysed. Results:  The mean average macular thickness, foveal thickness, inner/outer macular thickness and macular ...

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    23. Healing responses after bifurcation stenting with the dedicated TRYTON side-branch StentTM in combination with XIENCE-VTM stents: A clinical, angiography, fractional flow reserve and optical coherence tomography study

      Healing responses after bifurcation stenting with the dedicated TRYTON side-branch StentTM in combination with XIENCE-VTM stents: A clinical, angiography, fractional flow reserve and optical coherence tomography study

      Objectives: We evaluated healing responses with optical coherence tomography (OCT), and clinical and angiographic outcome after bifurcation stenting with the TRYTON Side-Branch StentTM.BackgroundDedicated bifurcation stents have been proposed as a potential alternative for treatment of true coronary bifurcation lesions. MethodsWe treated 20 consecutive patients with coronary bifurcation lesions and significant involvement of the side-branch (SB) with the TRYTON Stent and an additional XIENCE-VTM everolimus-eluting stent. At 9 months, we assessed the ratio of uncovered to total stent struts (RUTSS) with OCT, angiographic late luminal loss (LLL), and in-stent and in-segment restenosis. Clinical endpoints at 1 year included major adverse ...

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    24. Effect of multizone refractive multifocal contact lenses on the Cirrus HD OCT retinal measurements

      Effect of multizone refractive multifocal contact lenses on the Cirrus HD OCT retinal measurements

      Background Simultaneous vision multifocal contact lenses are widely used to alleviate the symptoms of presbyopia. These contact lenses create simultaneous retinal images due to the incoming light distribution being divided into two or more focuses. Our aim was to evaluate whether the multizone refractive multifocal contact lenses affect the measurements of the retinal nerve fibre layer (RNFL) and macular thickness using optical coherence tomography (OCT). Methods In this cross-over study, 30 eyes of 30 subjects with a mean age of 50.42 ± 7.82 years were fitted with multizone refractive multifocal contact lenses. Using the RNFL Thickness Analysis mode of ...

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