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    1. Pearls and Pitfalls of Optical Coherence Tomography Angiography Imaging: A Review

      Pearls and Pitfalls of Optical Coherence Tomography Angiography Imaging: A Review

      Optical coherence tomography angiography (OCTA) has significantly expanded our knowledge of the ocular vasculature. Furthermore, this imaging modality has been widely adopted to investigate different ocular and systemic diseases. In this review, a discussion of the fundamental principles of OCTA is followed by the application of this imaging modality to study the retinal and choroidal vessels. A proper comprehension of this imaging modality is essential for the interpretation of OCTA imaging applications in retinal and choroidal disorders.

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    2. Enlargement of the foveal avascular zone detected by optical coherence tomography angiography in diabetic children without diabetic retinopathy

      Enlargement of the foveal avascular zone detected by optical coherence tomography angiography in diabetic children without diabetic retinopathy

      Purpose Evaluation of foveal avascular zone (FAZ) in children with diabetes (DM) using OCTA. Methods We examined 112 diabetic children without DR aged 6–18 years and 30 age-matched controls using Topcon OCT Angiography and measured FAZ in superficial (SCP) and deep capillary plexus (DCP). The study group was divided into three subgroups depending on DM duration group 1: < 5 years ( n  = 40), group 2: 5–10 years ( n  = 42), group 3: > 10 years ( n  = 30). Results The mean DCP FAZ increased with DM duration from 502.2 μm 2 (SD 137.8) in group 1 to 523.9 μm ...

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    3. Macular perfusion changes assessed with optical coherence tomography angiography after vitrectomy for rhegmatogenous retinal detachment

      Macular perfusion changes assessed with optical coherence tomography angiography after vitrectomy for rhegmatogenous retinal detachment

      Purpose To explore macular perfusion changes in patients with rhegmatogenous retinal detachment (RRD) involved the macula following successful surgery and to evaluate the correlation between macular blood flow density and visual outcomes using optical coherence tomography angiography (OCTA). Methods This retrospective study included 14 eyes (14 patients) with macular-off RRD that underwent a standard three-port 23-gauge pars plana vitrectomy (PPV) and intraocular gas tamponade combined with phacoemulsification, aspiration, and intraocular lens implantation. OCTA was used to evaluate the macular perfusion changes throughout postoperative 12 weeks in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillary plexus (CCP). The ...

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    4. Optical coherence tomography analysis of filtering blebs after long-term, functioning trabeculectomy and XEN® stent implant

      Optical coherence tomography analysis of filtering blebs after long-term, functioning trabeculectomy and XEN® stent implant

      Purpose The purpose of this study was to use Triton® SweptSource OCT to evaluate the morphology of blebs formed when eyes are treated with XEN® implants and to compare these with the blebs in successfully functioning eyes after trabeculectomy (TB) and with eyes of healthy controls. Methods A cross-sectional, observational study. We analyzed 25 eyes, 15 after TB and 10 with XEN® implants, comparing them with 23 healthy eyes (controls). We evaluated the conjunctival morphology of the eyes using AS-OCT. The main parameters evaluated were bleb height, sub-epithelial fibrosis, epithelial thickness, and changes in intraocular pressure (IOP). Results We found ...

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    5. Assessment of strut coverage of everolimus-eluting platinum chromium stent 2 weeks after implantation by optical coherence tomography

      Assessment of strut coverage of everolimus-eluting platinum chromium stent 2 weeks after implantation by optical coherence tomography

      The SYNERGY coronary stent is new-generation drug-eluting stents, which has a thin-strut platinum–chromium platform with everolimus in a biodegradable polymer applied to the abluminal surface. It would be speculated that favorable arterial healing with early strut coverage could be achieved. The present study investigated the degree of strut coverage using optical coherence tomography (OCT) 2 weeks after SYNERGY implantation and clinical factors contributing to strut coverage. A total of 29 patients who underwent staged percutaneous coronary intervention (PCI) to residual lesions 2 weeks after the index PCI with SYNERGY stent implantation were enrolled. At the time of staged PCI ...

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      Mentions: Kenichi Fujii
    6. Prediction of corneal curvature radius after pterygium surgery using anterior segment optical coherence tomography

      Prediction of corneal curvature radius after pterygium surgery using anterior segment optical coherence tomography

      Purpose To investigate the validity of a multiple regression equation to predict postoperative corneal curvature radius (K) in simultaneous cataract and pterygium surgery using preoperative factors, including preoperative K. Study design Retrospective study. Methods Seventy eyes of 58 patients who had undergone initial pterygium removal at the Hayashi Eye Hospital between June 2014 and December 2017 were included in this study. In all eyes, the shape of the cornea could be measured using anterior segment optical coherence tomography 2 months after surgery. The independent variables were determined using a multiple regression equation that predicted the average postoperative K on the ...

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    7. Qualitative and quantitative neointimal characterization by optical coherence tomography in patients presenting with in-stent restenosis

      Qualitative and quantitative neointimal characterization by optical coherence tomography in patients presenting with in-stent restenosis

      Aims To describe optical coherence tomography (OCT) findings in patients with in-stent restenosis (ISR) and determine predictors of neointimal patterns and neoatherosclerosis. Methods and results Patients undergoing OCT prior to PCI for ISR in three European centres were included. Analyses were performed in a core laboratory. Qualitative and quantitative [gray-scale signal intensity (GSI)] neointima analyses were performed on a per quadrant basis. A total of 107 patients were included. Predominantly homogeneous lesions included 4.5% (0.0–14.3) non-homogeneous quadrants, while predominantly non-homogeneous ones included 28.1% (20.3–37.5) homogeneous quadrants. Mean GSI values differed significantly between ...

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    8. Choroidal neovascularization imaging using multiple en face optical coherence tomography angiography image averaging

      Choroidal neovascularization imaging using multiple en face optical coherence tomography angiography image averaging

      Purpose To determine the effects of averaging five en face optical coherence tomography angiographic (OCTA) images on the quality of the images in eyes with a choroidal neovascularization (CNV). Methods Twenty-seven eyes of 25 patients (18 men, 7 women; average age 71.0 years) with a CNV were examined by OCTA (OCT HS-100, Canon. Japan). A 3 × 3-mm image including the CNV was recorded and automatically segmented between the retinal outer layers. Analyses were performed on a single image (S-image) and the average of five single images of the same area (A-images). The region of the CNV was selected by ...

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    9. Automatic Detection of Blood Vessels in Optical Coherence Tomography Scans

      Automatic Detection of Blood Vessels in Optical Coherence Tomography Scans

      The aim of this research is to develop a new automated blood vessel (BV) detection algorithm for optical coherence tomography (OCT) scans and corresponding fundus images. The algorithm provides a robust method to detect BV shadows (BVSs) using Radon transformation and other supporting image processing methods. The position of the BVSs is determined in OCT scans and the BV thickness is measured in the fundus images. Additionally, the correlation between BVS thickness and retinal nerve fiber layer (RNFL) thickness is determined. This correlation is of great interest since glaucoma, for example, can be identified by a loss of RNFL thickness.

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    10. Do microvascular changes occur preceding neural impairment in early-stage diabetic retinopathy? Evidence based on the optic nerve head using optical coherence tomography angiography

      Do microvascular changes occur preceding neural impairment in early-stage diabetic retinopathy? Evidence based on the optic nerve head using optical coherence tomography angiography

      Aims To evaluate the microvascular and neural differences of the optic nerve head (ONH) between type 2 diabetes mellitus (T2DM) subjects and controls. Methods This was a cross-sectional observational study. One hundred and eight eyes of 108 T2DM subjects with or without diabetic retinopathy (DR) (54 preclinical DR and 54 mild-to-moderate DR) were included. Fifty-two eyes of 52 healthy subjects were included as controls. The 4.5-mm Angio Disc scan mode and the ganglion cell complex scan mode were performed with all participants using AngioVue software 2.0 of the optical coherence tomography angiography (OCTA) device. Results Regarding ONH radial ...

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    11. 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 ...

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    12. 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 ...

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    13. 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 ...

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    14. 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 ...

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    15. 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 ...

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    16. 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 ...

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    17. 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 ...

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    18. 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.

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    19. 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.

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    20. 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 ...

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    21. 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 ...

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    22. 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 ...

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    23. 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 ...

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