1. 1-24 of 680 1 2 3 4 ... 27 28 29 »
    1. Vascular and structural alterations of the choroid evaluated by optical coherence tomography angiography and optical coherence tomography after half-fluence photodynamic therapy in chronic central serous chorioretinopathy

      Vascular and structural alterations of the choroid evaluated by optical coherence tomography angiography and optical coherence tomography after half-fluence photodynamic therapy in chronic central serous chorioretinopathy

      Purpose To concurrently evaluate the effect of half-fluence photodynamic therapy (hf PDT) on choriocapillaris (CC) perfusion and choroidal structure in chronic central serous chorioretinopathy (CSC). Methods This prospective study included 48 eyes of 41 patients with chronic CSC. Enhanced depth imaging optical coherence tomography and optical coherence tomography angiography (OCTA) images were analyzed. Choroidal area (CA), luminal area (LA), and stromal area (SA) were computed using Image J software. Results One month after hf-PDT, total CA decreased to 1.312 mm 2 from 1.490 mm 2 ( p  < 0.001), LA decreased to 0.981 mm 2 from 1.097 ...

      Read Full Article
    2. Impact of segmentation density on spectral domain optical coherence tomography assessment in Stargardt disease

      Impact of segmentation density on spectral domain optical coherence tomography assessment in Stargardt disease

      Purpose Automated spectral domain optical coherence tomography (SD-OCT) segmentation algorithms currently do not perform well in segmenting individual intraretinal layers in eyes with Stargardt disease (STGD). We compared selective B-scan segmentation strategies for generating mean retinal layer thickness and preserved area data from SD-OCT scans in patients with STGD1. Methods Forty-five eyes from 40 Stargardt patients were randomly selected from the ongoing Natural History of the Progression of Atrophy Secondary to Stargardt Disease (ProgStar) study. All eyes underwent SD-OCT using a standard macular volume consisting of 1024 × 49 equally spaced B-scans within a 20 × 20 degree field centered on the ...

      Read Full Article
    3. Fundus autofluorescence and spectral domain optical coherence tomography as predictors for long-term functional outcome in rhegmatogenous retinal detachment

      Fundus autofluorescence and spectral domain optical coherence tomography as predictors for long-term functional outcome in rhegmatogenous retinal detachment

      Purpose To detect pre- and postoperative retinal changes in fundus autofluorescence (AF) and spectral domain optical coherence tomography (SD-OCT) and to correlate these with functional outcome in patients with primary rhegmatogenous retinal detachment (RRD). Methods A prospective, 30-month study of patients operated with 25-gauge vitrectomy for primary RRD. Patients were examined preoperatively and after 6 and 30 months, using ultrawide-field AF images (UWFI) (Optos 200Tx) and SD-OCT (Topcon 3D OCT-2000) imaging. Results Of 84 patients (84 eyes) included at baseline, 100.0 and 86.9% were re-examined at month 6 and 30, respectively. Preoperative findings such as macular attachment, detachment ...

      Read Full Article
    4. Measuring Barrett’s Epithelial Thickness with Volumetric Laser Endomicroscopy as a Biomarker to Guide Treatment

      Measuring Barrett’s Epithelial Thickness with Volumetric Laser Endomicroscopy as a Biomarker to Guide Treatment

      Background Radiofrequency ablation (RFA) treatment outcomes vary for unknown reasons. One hypothesis is that variations in Barrett’s epithelial thickness (BET) are associated with reduced RFA efficacy for thicker BET and strictures for thinner BET. Volumetric laser endomicroscopy (VLE) is an imaging modality that acquires high-resolution, depth-resolved images of BE. However, the attenuation of light by tissue and the lack of layering in Barrett’s tissue challenge BET measurements and the study of relationships between thickness and RFA outcomes. We aimed to quantify BET and compared the reliability of standard and contrast-enhanced VLE images. Methods Baseline VLE scans from BE ...

      Read Full Article
    5. Optical Coherence Tomography for Fingerprint Presentation Attack Detection (Book Chapter)

      Optical Coherence Tomography for Fingerprint Presentation Attack Detection (Book Chapter)

      New research in fingerprint biometrics uses optical coherence tomography (OCT) technology to acquire fingerprints from where they originate below the surface of the skin. The penetrative nature of this technology means that rich information is available regarding the structure of the skin. This access, in turn, enables new techniques in detecting spoofing attacks, and therefore also introduces mitigation steps against current presentation attack methods. These techniques include the ability to detect fake fingers; fake layers applied above the skin; differentiate between fakes and surface skin conditions; and liveness detection based on, among others, the analysis of eccrine glands and capillary ...

      Read Full Article
    6. Retinal vascular density evaluated by optical coherence tomography angiography in macular telangiectasia type 2

      Retinal vascular density evaluated by optical coherence tomography angiography in macular telangiectasia type 2

      Purpose To evaluate the retinal and choroidal vascular changes through optical coherence tomography angiography (OCTA) in patients with macular telangiectasia type 2 (MacTel 2). Methods Our study included 20 patients (40 eyes) with MacTel 2, and age-matched and sex-matched 18 subjects (36 eyes) in the control group. Fundus color photographs, fundus autofluorescence, fundus fluorescein angiography, spectral-domain optical coherence tomography and OCTA were performed. Foveal vascular density and parafoveal vascular density (PFVD), and foveal retinal thickness and parafoveal retinal thickness, choroidal thickness (CT) and retinal ganglion cell–inner plexiform layer (GCIPL) were compared between MacTel 2 patients and normal age-matched controls ...

      Read Full Article
    7. Plaque characteristics and slow flow during percutaneous coronary intervention of irregular protrusion by optical coherence tomography

      Plaque characteristics and slow flow during percutaneous coronary intervention of irregular protrusion by optical coherence tomography

      Irregular protrusion on optical coherence tomography (OCT) is associated with clinical events and target lesion revascularization. We investigated clinical and procedure characteristics, plaque characteristics, slow flow after stent implantation, and clinical outcomes with irregular protrusion using OCT. Eighty-four lesions in 76 patients undergoing OCT before percutaneous coronary intervention were evaluated. Irregular protrusion was defined as protrusion of material with an irregular surface into the lumen between stent struts with a maximum height of ≥100 μm. Lesions with irregular protrusion were found in 56% (47/84). Compared with lesions without irregular protrusion, those with irregular protrusion had significantly higher low-density lipoprotein ...

      Read Full Article
    8. Optical Coherence Tomography (OCT) for Examination of Artworks (Book Chapter)

      Optical Coherence Tomography (OCT) for Examination of Artworks (Book Chapter)

      Optical coherence tomography is a fast, non-invasive technique of structural analysis utilising near-infrared radiation. Examples of using OCT, for obtaining cross-sectional images of objects of craftsmanship and an easel painting have been shown. Issues regarding the technique of execution and destruction phenomena were resolved non-invasively. In some cases, the secondary alterations can be identified and localised within the object’s structure which helps in authentication of the artwork.

      Read Full Article
    9. Optical Coherence Tomography (Book Chapter)

      Optical Coherence Tomography (Book Chapter)

      Optical coherence tomography (OCT) has enhanced our understanding and management of retinal diseases, ever since the time-domain OCT was introduced in the early 2000s. The introduction of spectral-domain OCT in the mid-2000s and the later introduction of swept-source OCT provided faster scanning strategies and high-resolution images of the retina and choroid.

      Read Full Article
    10. Swept source optical coherence tomography analysis of choroidal thickness in macular telangiectasia type 2: a case-control study

      Swept source optical coherence tomography analysis of choroidal thickness in macular telangiectasia type 2: a case-control study

      Purpose There has been a recent interest in the association of macular telangiectasia (MacTel) type 2 with central serous choroidopathy and other pachychoroid disorders. This study was performed to assess the subfoveal choroidal thickness (SFCT) in patients with MacTel type 2 and compare it with healthy controls using swept source optical coherence tomography (SS-OCT). Methods It was a retrospective case-control study performed at a tertiary eye care center. The cases constituted patients with MacTel type 2 detected over the last 2 years (April 2016 to March 2018). The controls were healthy adults with no posterior segment pathology. The patients were ...

      Read Full Article
    11. Evaluation of retinal vasculature before and after treatment of children with obstructive sleep apnea-hypopnea syndrome by optical coherence tomography angiography

      Evaluation of retinal vasculature before and after treatment of children with obstructive sleep apnea-hypopnea syndrome by optical coherence tomography angiography

      Purpose To evaluate the effect of adenoidectomy on the brains of children with obstructive sleep apnea-hypopnea syndrome (OSAS) through observation of the alteration of retinal perfusion by optical coherence tomography angiography (OCTA). Methods Sixty-two children with OSAS (124 eyes; 5.94 ± 1.64 years old; 53.2% boys) were enrolled in this study. Their retinal vascular network density indices, including vascular diameter (VD), vascular area density (VAD), vessel skeleton density (VSD), vessel perimeter index (VPI) on the macular superficial/deep capillary plexus (SCP/DCP), and the size of the foveal avascular zone (FAZ) were analyzed by OCTA before treatment and ...

      Read Full Article
    12. Optical coherence tomography imaging of melanoma skin cancer

      Optical coherence tomography imaging of melanoma skin cancer

      No consensus guidelines exist on the use of optical coherence tomography (OCT) for diagnosis of cutaneous melanoma. The objectives of this review are to provide a descriptive review of the literature on characteristics of cutaneous melanomas seen on high-definition OCT (HD-OCT), speckle variance OCT (SV-OCT), and conventional OCT and to compare their diagnostic ability with that of histopathology. A review of PubMed and Google Scholar identified all available literature on OCT in melanoma skin cancer that included all in vivo and ex vivo studies on human or human tissues and excluded all studies on non-human subjects or animal studies. Two ...

      Read Full Article
    13. Retinal vessel optical coherence tomography images for anemia screening

      Retinal vessel optical coherence tomography images for anemia screening

      Anemia is a disease that leads to low oxygen carrying capacity in the blood. Early detection of anemia is critical for the diagnosis and treatment of blood diseases. We find that retinal vessel optical coherence tomography (OCT) images of patients with anemia have abnormal performance because the internal material of the vessel absorbs light. In this study, an automatic anemia screening method based on retinal vessel OCT images is proposed. The method consists of seven steps, namely, denoising, region of interest (ROI) extraction, layer segmentation, vessel segmentation, feature extraction, feature dimensionality reduction, and classification. We propose gradient and threshold algorithm ...

      Read Full Article
    14. Efficacy of intravitreal aflibercept monotherapy in retinopathy of prematurity evaluated by periodic fluorescence angiography and optical coherence tomography

      Efficacy of intravitreal aflibercept monotherapy in retinopathy of prematurity evaluated by periodic fluorescence angiography and optical coherence tomography

      Purpose To evaluate the efficacy of intravitreal aflibercept (IVA) in vascular and macular maturation in neonates with type 1 retinopathy of prematurity (ROP) and aggressive posterior retinopathy of prematurity (APROP). Materials and methods Thirty-six eyes of 18 patients with type 1 ROP or APROP in zone I or posterior zone II were enrolled in our study. At baseline, only fluorescein angiography (FA) was performed. After IVA injection, both FA and optical coherence tomography (OCT) were performed after 6.8 ± 0.8 (range 6–8) and 19 ± 0.9 (range 18–20) weeks to follow vascular and macular changes. Results Both ...

      Read Full Article
    15. Choroidal thickness in preeclampsia measured by spectral-domain optical coherence tomography

      Choroidal thickness in preeclampsia measured by spectral-domain optical coherence tomography

      Purpose To compare choroidal thickness (CT) measurements in preeclamptic and healthy women in the third trimester of pregnancy using optical coherence tomography. Methods This cross-sectional study included 148 eyes of 74 women, divided into two groups: 27 healthy pregnant women in the third trimester (control group) and 47 age-matched pregnant women in the third trimester with preeclampsia (PE group). Of the 47 subjects in preeclampsia group, 26 were classified as having mild PE and 21 as having severe PE. Choroidal thickness was measured at ten different locations: at the fovea and every 500 µm from the fovea up to 2500 ...

      Read Full Article
    16. Optical Coherence Tomography in Urologic Oncology: a Comprehensive Review

      Optical Coherence Tomography in Urologic Oncology: a Comprehensive Review

      Introduction Optical coherence tomography (OCT) is being investigated in urologic oncology for optical diagnosis. This comprehensive review analyzes the current state of development of OCT for bladder, upper urinary tract, kidney, prostate, testis, and penis cancer. Also, the potential role of OCT with regard to the current diagnostic pathways is critically appraised to guide future developments. Methods Embase and Pubmed were systematically searched for English and German articles on OCT in humans up to December 2017. Reviews were excluded. Case reports were excluded, unless they presented a landmark in the development of OCT. Results Out of 878 articles, 17 relevant ...

      Read Full Article
    17. Association Between TG-to-HDL-C Ratio and In-Stent Stenosis Under Optical Coherence Tomography Guidance

      Association Between TG-to-HDL-C Ratio and In-Stent Stenosis Under Optical Coherence Tomography Guidance

      We determined the relevance between the TG-to-HDL-C ratio and stent restenosis. Ninety-nine patients with in-stent stenosis (ISR) who were admitted to An Zhen Hospital in Beijing between April 2014 and June 2017 were selected. At the same time, 122 patients with coronary stenosis <50% were selected. All patients were tested for TG, HDL-C, and TG/HDL-C ratio. Optical coherence tomography (OCT) can assess microscopic status in all ISR patients. The proportion of male and Diabetic patients were significantly higher for ISR. There were differences in the prevalence of cigarette smokers among the different tissue types, among which the layered tissue ...

      Read Full Article
    18. Automated macular segmentation with spectral domain optical coherence tomography in the fellow eyes of patients with unilateral retinal vein occlusion

      Automated macular segmentation with spectral domain optical coherence tomography in the fellow eyes of patients with unilateral retinal vein occlusion

      Purpose To assess the change in the macular layers in the fellow eyes of unilateral retinal vein occlusion (RVO) patients and to evaluate whether certain layers are more affected based on RVO type. Methods This retrospective study included 87 fellow eyes of patients with unilateral RVO (26 central, 61 branch) and 105 eyes of 105 subjects without RVO. Spectral domain optical coherence tomography was used for automatized retinal segmentation. The thicknesses of retinal nerve fiber layer (RNFL), ganglion cells, inner plexiform, inner nuclear, outer plexiform, outer nuclear, photoreceptor layers, overall inner retinal layers and retinal pigment epithelium (RPE) were documented ...

      Read Full Article
    19. Visualization of the pulp chamber roof and residual dentin thickness by spectral-domain optical coherence tomography in vitro

      Visualization of the pulp chamber roof and residual dentin thickness by spectral-domain optical coherence tomography in vitro

      The aim of this study was to evaluate the ability of spectral-domain optical coherence tomography (SD-OCT) to display the roof of the pulp chamber and to estimate the residual dentin thickness (RDT) of the pulp complex. The roots of 20 extracted human molars were embedded in epoxy resin, and crowns were longitudinally sectioned in the mesial-distal direction, exposing the pulp chamber. The coronal part of the crown was removed up to an RDT to the pulp chamber roof of 2 mm. Samples were imaged by SD-OCT from coronal view and by light microscopy (LM) in the sagittal plane. Using a ...

      Read Full Article
    20. An Overview of OCT Techniques for Detection of Ophthalmic Syndromes

      An Overview of OCT Techniques for Detection of Ophthalmic Syndromes

      The retina is an essential part of the human eye. It is a very small part at the subsequent pole of the human eye, and it is composed of a tissue cell that can detect the presence of light. The tissue is sensitive enough to detect the amount of light present, its intensity, and a range of different wavelengths as well. These tissues generate nerve signals, and those signals are passed to the brain via the optic nerve. If the retina malfunctions, then different retinal disorders can occur such as diabetic retinopathy, glaucoma, and pathologic myopia. These can be considered ...

      Read Full Article
    21. The diagnostic value of optical coherence tomography angiography in diabetic retinopathy: a systematic review

      The diagnostic value of optical coherence tomography angiography in diabetic retinopathy: a systematic review

      Purpose Diabetic retinopathy (DR) is one of the leading causes of blindness worldwide. Accurate investigative tools are essential for the early diagnosis and monitoring of the disease. Optical coherence tomography angiography (OCTA) is a recently developed technology that enables visualisation of the retinal microvasculature. Methods A systematic review of the literature was performed to examine the diagnostic use of OCTA in DR to date. Medline, EMBASE, and Cochrane databases were searched to find relevant studies. Sixty-one original studies were selected for the review. Results and discussion OCTA has demonstrated the ability to identify microvascular features of DR such as microaneurysms ...

      Read Full Article
    22. Colocalization of neurons in optical coherence microscopy and Nissl-stained histology in Brodmann’s area 32 and area 21

      Colocalization of neurons in optical coherence microscopy and Nissl-stained histology in Brodmann’s area 32 and area 21

      Optical coherence tomography is an optical technique that uses backscattered light to highlight intrinsic structure, and when applied to brain tissue, it can resolve cortical layers and fiber bundles. Optical coherence microscopy (OCM) is higher resolution (i.e., 1.25 µm) and is capable of detecting neurons. In a previous report, we compared the correspondence of OCM acquired imaging of neurons with traditional Nissl stained histology in entorhinal cortex layer II. In the current method-oriented study, we aimed to determine the colocalization success rate between OCM and Nissl in other brain cortical areas with different laminar arrangements and cell packing ...

      Read Full Article
    1-24 of 680 1 2 3 4 ... 27 28 29 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks