1. 1-24 of 898 1 2 3 4 ... 36 37 38 »
    1. Optical coherence tomography and video recording of a case of bilateral contractile peripapillary staphyloma

      Optical coherence tomography and video recording of a case of bilateral contractile peripapillary staphyloma

      Purpose To report a case of bilateral contractile peripapillary staphyloma (CPS) examined by optical coherence tomography (OCT) and video recording. Observation We report the clinical history of a male infant with bilateral CPS. Two ophthalmic examinations under general anesthesia were performed during follow-up examinations. During the first fundus examination when the infant was 4 months old, we observed staphylomatous excavation around the optic disc, an almost normal disc appearance at the bottom of the excavation, and irregular contraction bilaterally. OCT images showed deep excavation around the optic disc bilaterally and hyperreflective tissue beneath the sclera in the right eye. During ...

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    2. Voltage Noise and Jitter Analysis for Swept Source Optical Coherence Tomography using KTa1-xNbxO3 Deflector

      Voltage Noise and Jitter Analysis for Swept Source Optical Coherence Tomography using KTa1-xNbxO3 Deflector

      This paper describes voltage noise and jitter analysis for the depth deviation of a point spread function in a swept source optical coherence tomography system using a KTa1-xNbxO3 deflector. An interference waveform with voltage noise and jitter was simulated according to a previous report. Typical values for the voltage noise ΔVTYP and jitter ΔtTYPwere also obtained from a previous report and experiment. It was determined that the depth deviation is limited by the ΔtTYP of the system. Therefore, the quality of the tomographic image can be efficiently improved by reducing jitter.

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      Mentions: NTT
    3. Protocol adaptation of OCT in lower limb arteries revascularisation

      Protocol adaptation of OCT in lower limb arteries revascularisation

      In lower limb arteries, assessment of stent apposition and/or the single opening of the diseased artery remains poor since this relies on 2D angiogram. Extrapolating experience gained with coronary arteries, optical coherence tomography (OCT) could provide 3D reconstructions of the arterial wall and the stent implanted. A modified protocol of OCT acquisition, which usually includes large amount of iodine contrast flush, is presented here in 3 patients with long and complex occlusion of the superficial femoral artery (SFA). Its potential benefits and wider application to improve patient outcomes are discussed.

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    4. Novel application of anterior segment optical coherence tomography for periocular imaging

      Novel application of anterior segment optical coherence tomography for periocular imaging

      Objective This study aims to assess the use of optical coherence tomography (OCT) imaging for periocular skin lesions and to determine which characteristic features of these images can be correlated to histopathology . Design This is an ongoing prospective study with Research Ethics Board approval. Participants Fifty patients over 18 years old with lesions clinically suspicious of nonmelanoma skin cancer on the periocular region were included in this study. Methods After consent was obtained, clinical photographs and dermatoscopic images were obtained (DermLite II Hybrid M) from the lesion and its contralateral side. Subsequently, the patient was subjected to OCT imaging using ...

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    5. Retinal nerve fiber layer analysis in cocaine users

      Retinal nerve fiber layer analysis in cocaine users

      Cocaine is a well-known factor of tissue ischemia and may be related to thinning of the inner retinal layers. The present study aimed to evaluate and determine whether cocaine users show retinal nerve fiber layer (RNFL) thinning by means of spectral-domain optical coherence tomography. A group of 17 cocaine users and 18 non-users were recruited for complete ophthalmologic examination. Spectral domain optical coherence tomography (Cirrus OCT) was used to evaluate peripapillary RNFL and macular thickness. The average RNFL measurement in the cocaine users group was significantly thinner compared to the control group. Subjects in the cocaine users group showed significant ...

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    6. Optical coherence tomography for intracranial aneurysms: a new method for assessing the aneurysm structure

      Optical coherence tomography for intracranial aneurysms: a new method for assessing the aneurysm structure

      Background There is a lack of precise methods for predicting the risk of aneurysm rupture. Therefore, prophylactic treatment is used, which leads to unnecessary potential complications. A new modality enabling a more accurate risk assessment is needed. Optical coherence tomography (OCT) is a new-generation imaging technology that has astonishing resolution for vascular imaging. In this study, OCT was used for the evaluation of intracranial aneurysms. Methods In vivo OCT imaging was performed for aneurysms induced in 6 rabbits and in 9 intracranial aneurysm patients. Catheters were cut short to prevent any extra length from damaging aneurysms and tissues. Images of ...

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      Mentions: Fudan University
    7. Choroidal thickness in healthy eyes using enhanced depth imaging optical coherence tomography and comparison with cases of retinitis pigmentosa

      Choroidal thickness in healthy eyes using enhanced depth imaging optical coherence tomography and comparison with cases of retinitis pigmentosa

      Introduction The goal of this study was to measure by spectral domain optical coherence tomography (SD-OCT) with EDI the choroidal thickness in healthy subjects and to compare these parameters with those of patients with retinitis pigmentosa (RP). Methods Data were obtained from 60 healthy patients without history or family history of retinal or choroidal disease or glaucoma . A case-control study was also conducted on 40 eyes of 20 patients with RP and 40 eyes of 20 healthy refraction- and age-matched controls, selected from among the 60 healthy patients. OCT was used with the EDI protocol. The primary outcome measure was ...

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    8. Point-of-care endoscopic optical coherence tomography detects changes in mucosal thickness in ARDS due to smoke inhalation and burns

      Point-of-care endoscopic optical coherence tomography detects changes in mucosal thickness in ARDS due to smoke inhalation and burns

      Background The prevalence of acute respiratory distress syndrome (ARDS) in mechanically ventilated burn patients is 33%, with mortality varying from 11–46% depending on ARDS severity. Despite the new Berlin definition for ARDS, prompt bedside diagnosis is lacking. We developed and tested a bedside technique of fiberoptic-bronchoscopy-based optical coherence tomography (OCT) measurement of airway mucosal thickness (MT) for diagnosis of ARDS following smoke inhalation injury (SII) and burns. Methods 16 female Yorkshire pigs received SII and 40% thermal burns. OCT MT and PaO 2 -to-FiO 2 ratio (PFR) measurements were taken at baseline, after injury, and at 24, 48, and ...

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    9. Absence of the foveal avascular zone in a nanophthalmic child revealed by optical coherence tomography angiography

      Absence of the foveal avascular zone in a nanophthalmic child revealed by optical coherence tomography angiography

      Purpose Optical coherence tomography angiography (OCTA) is a new non-invasive imaging technique that does not require the use of contrast agents and that allows the visualization of the retinal microvasculature in a layer-by-layer manner without bright light. This merit allows us to obtain the fundus image in children. Retinal vessels are typically absent from the center of the fovea , an area known as the foveal avascular zone (FAZ). The purpose of the present case study was to evaluate the FAZ in a nanophthalmic pediatric patient with OCTA. Obsevations A 6-year-old girl was referred to the Hiroshima University Hospital because of ...

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    10. Color vision testing versus pattern visual evoked potentials and optical coherence tomography parameters in subclinical optic nerve involvement in multiple sclerosis

      Color vision testing versus pattern visual evoked potentials and optical coherence tomography parameters in subclinical optic nerve involvement in multiple sclerosis

      Acute idiopathic demyelinating optic neuritis is frequently the initial manifestation of multiple sclerosis (MS). We aimed to discuss the value of color vision testing to detect possible optic nerve involvement in patients with MS who had no history of optic neuritis. We evaluated color vision with Farnsworth-Munsell 100 (FM-100) hue test. Total error scores (TES), partial error scores for the red-green axis (RGS) and blue-yellow axis (BYS) were calculated. Topographic optic disc parameters (RNFL, RA, DA, CV, RV, and vertical C/D ratio), total macular volume (TMV), central macular thickness (CMT), and retinal ganglion cell layer (RGCL) were determined using ...

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    11. Detecting Glaucoma Progression Using Guided Progression Analysis with Optical Coherence Tomography and Visual Field Assessment in Eyes Classified by International Classification of Disease Severity Codes

      Detecting Glaucoma Progression Using Guided Progression Analysis with Optical Coherence Tomography and Visual Field Assessment in Eyes Classified by International Classification of Disease Severity Codes

      Purpose To compare the detection and rates of progressive retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) loss with spectral domain optical coherence tomography (SDOCT) and visual field (VF) loss using Guided Progression Analysis (GPA, Carl Zeiss Meditec, Dublin, CA) in glaucomatous eyes classified using International Classification of Disease diagnosis codes (ICD). Design Retrospective cohort study. Participants Glaucoma patients with at least 3 years of follow-up and a minimum of 4 SDOCT and 5 reliable VF exams. Methods Glaucoma severity was classified using ICD-10- diagnosis codes. Rates of RNFL, macular GCIPL and VF loss were calculated ...

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    12. Data on SD-OCT image acquisition, ultrastructural features, and horizontal tissue shrinkage in the porcine retina

      Data on SD-OCT image acquisition, ultrastructural features, and horizontal tissue shrinkage in the porcine retina

      The data presented in this article are related to the research paper entitled “Correlation of Spectral Domain Optical Coherence Tomography with Histology and Electron Microscopy in the Porcine Retina” (Xie et al., 2018) [2]. This research data highlights our technique for retinal fundus image acquisition during spectral domain optical coherence tomography (SD-OCT) in a large animal model. Low and high magnification electron micrographs are included to demonstrate the ultrastructural features of the porcine retina. Data on horizontal tissue shrinkage during processing of the porcine retina are presented.

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    13. Lid-parallel conjunctival fold (LIPCOF) morphology imaged by optical coherence tomography and its relationship to LIPCOF grade

      Lid-parallel conjunctival fold (LIPCOF) morphology imaged by optical coherence tomography and its relationship to LIPCOF grade

      Purpose Lid-parallel conjunctival folds (LIPCOF) are a well-accepted clinical sign in dry eye diagnosis. Commonly, LIPCOF is classified by grading the number of folds observed by slit-lamp microscope. This study investigated the relationship between subjective grading scale and LIPCOF morphology imaged by optical coherence tomography (OCT). Methods Temporal and nasal LIPCOF of 42 subjects (mean age 27.3 ± 8.4 (SD) years; 13 M, 29 F) were observed and classified by an experienced optometrist using the Pult LIPCOF grading scale (0: no permanent, lid-parallel conjunctival fold; 1: one fold; 2: two folds, 3: three or more folds). Additionally, LIPCOF cross-sectional ...

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    14. Feature-oriented singular value shrinkage for optical coherence tomography image

      Feature-oriented singular value shrinkage for optical coherence tomography image

      Optical coherence tomography (OCT) is a non-invasive optical imaging modality that has been widely used in the field of medical diagnosis. However, OCT images are often degraded by speckle noise. To address this problem, this paper proposes a two-stage feature-oriented singular value shrinkage algorithm in a low-rank approximation framework, for speckle noise reduction and contrast enhancement of intra-retinal layers of OCT images. First, a weighted absolute distance is employed to find nonlocal similar patches that exhibit high correlation to a given reference one. Next, the singular values of the group matrix formed by similar patches are shrunk by mixed thresholding ...

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    15. Peripapillary Retinal Nerve Fiber Layer Thickness Measured by Optical Coherence Tomography in Different Clinical Subtypes of Multiple Sclerosis

      Peripapillary Retinal Nerve Fiber Layer Thickness Measured by Optical Coherence Tomography in Different Clinical Subtypes of Multiple Sclerosis

      Background Multiple sclerosis (MS) is a chronic inflammatory demyelinating autoimmune disease of the central nervous system (CNS) with axonal degeneration as major determinant of neurological disability. Assessment of unmyelinated retinal nerve fibers using optical coherence tomography (OCT) may be useful for diagnosing the onset and rate of progression of neurodegeneration. Objective To assess the incidence and severity of damage of the peripapillary retinal nerve fiber layer (RNFL) in two different MS subtypes: non-progressive [Prog(-)MS] and progressive [Prog(+)MS]. Methods 48 patients (96 eyes) with MS were included: 13 males, 35 females; aged 22-62 years (mean 38.8; SD ±10 ...

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    16. Numerical Investigation of Atherosclerotic Plaque Rupture using Optical Coherence Tomography Imaging and XFEM

      Numerical Investigation of Atherosclerotic Plaque Rupture using Optical Coherence Tomography Imaging and XFEM

      Myocardial infarction contributes to most fatalities in which atherosclerotic plaque disruption is the underlying pathology. From the mechanics view point, the pulsatile blood flow in the arteries resembles a fatigue environment and generates stresses that affect the rupture of the atherosclerotic plaque. In this context, patient-specific optical coherence tomography (OCT) was used to develop the fatigue crack growth behavior. The impact of location specific morphological features and their relative effect on plaque life were discussed. EXtended Finite Element Method (XFEM) and Paris’ Law were employed to investigate the fatigue crack growth. Twelve 2D slices from six patients were reconstructed for ...

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    17. A marine biofilm flow cell for in situ screening marine fouling control coatings using optical coherence tomography

      A marine biofilm flow cell for in situ screening marine fouling control coatings using optical coherence tomography

      A novel fouling marine flow cell was designed and fitted with a clear plastic lid to allow real-time imaging of biofilms using optical coherence tomography (OCT). Marine biofilms were grown under controlled shear flow on coupons coated with 6 different biocidal antifouling coatings (SPC1, SPC2, SPC3, SPC4, CDP1 and CDP2, AkzoNobel) and one inert coating which contained no biocidal actives (NB-D) for 8 weeks. One set of coupons coated with NB was statically immersed in sea water during the same time period (NB-S). Biofilm removal was assessed by increasing the flow velocity while OCT simultaneously measured the biofilm cross-sectional area ...

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    18. Comparison of ultrasonic pachymetry and Fourier-domain optical coherence tomography for measurement of corneal thickness in dogs with and without corneal disease

      Comparison of ultrasonic pachymetry and Fourier-domain optical coherence tomography for measurement of corneal thickness in dogs with and without corneal disease

      Several ultrasonic and Fourier-domain optical coherence tomography (FD-OCT) pachymeters are used to measure corneal thickness in canine patients and research subjects. This study assessed the reliability of and consistency between two ultrasonic pachymetry (USP) devices, Pachette 3 and Accupach VI, as well as automated and manual measurements obtained using FD-OCT in dogs with and without corneal disease. Corneal thickness measurements were compiled from 108 dogs and analyzed using mixed effects linear regression, with Bonferonni adjustments for post-hoc comparisons, to determine the effects of age, weight and disease state. Data are presented as predicted mean ± standard error. Canine corneal disease can ...

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      Mentions: UC Davis
    19. Achilles tendon thickening is associated with disease severity and plaque vulnerability in patients with coronary artery disease

      Achilles tendon thickening is associated with disease severity and plaque vulnerability in patients with coronary artery disease

      Background Tendon xanthomas are accumulations of collagen and macrophages which contain cholesterol esters and a marker of high risk for coronary artery disease (CAD). Objective To clarify whether the presence of Achilles tendon thickening (ATT) was associated with disease severity and plaque vulnerability in patients with CAD. Methods A total of 241 consecutive patients who underwent percutaneous coronary intervention and ATT assessment were analyzed. ATT was defined as Achilles tendon thickness of 9 mm or more on radiograph. The severity of CAD and plaque vulnerability were assessed by the findings on angiogram and optical coherence tomography, respectively. Results ATT was ...

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    20. Classification of burn injury using Raman spectroscopy and optical coherence tomography: An ex-vivo study on porcine skin

      Classification of burn injury using Raman spectroscopy and optical coherence tomography: An ex-vivo study on porcine skin

      Accurate depth assessment of burn wounds is a critical task to provide the right treatment and care. Currently, laser Doppler imaging is able to provide better accuracy compared to the standard clinical evaluation. However, its clinical applicability is limited by factors like scanning distance, time, and cost. Precise diagnosis of burns requires adequate structural and functional details. In this work, we evaluated the combined potential of two non-invasive optical modalities, optical coherence tomography (OCT) and Raman spectroscopy (RS), to identify degrees of burn wounds (superficial partial-thickness (SPT), deep partial-thickness (DPT), and full-thickness (FT)). OCT provides morphological information, whereas, RS provides ...

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    21. Early retinal and choroidal effect of photodynamic treatment in patients with polypoidal choroidal vasculopathy with or without anti-vascular endothelial growth factor: An optical coherence tomography angiography study

      Early retinal and choroidal effect of photodynamic treatment in patients with polypoidal choroidal vasculopathy with or without anti-vascular endothelial growth factor: An optical coherence tomography angiography study

      Purpose To evaluate the early retinal and choroidal effects of the anti-vascular endothelial growth factor (anti-VEGF) therapy combined with photodynamic therapy (PDT) for polypoidal choroidal vasculopathy (PCV). Methods Patients diagnosed as having PCV were included in the study. In group 1, intravitreal ranibizumab and PDT was applied to six eyes. In group 2, PDT treatment only was applied to four eyes. Optical coherence tomography (OCT) angiography images and best-corrected visual acuity (BCVA) were taken from all patients before treatment and 3 days after surgery. Results The mean age of the patients was 66.00 ± 6.28 years. In group 1 ...

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    22. Optical coherence tomography angiography features of optic nerve head drusen and nonarteritic anterior ischemic optic neuropathy

      Optical coherence tomography angiography features of optic nerve head drusen and nonarteritic anterior ischemic optic neuropathy

      Objective To evaluate the optic disc microvasculature in optic nerve head drusen (ONHD) vasculature in comparison to acute nonarteritic anterior ischemic optic neuropathy (NAION) and normal eyes using optical coherence tomography angiography (OCT-A). Methods Ten eyes with ONHD, 10 eyes with acute NAION, and 10 healthy eyes were included in this prospective, comparative, observational case series. OCT-A imaging was performed on the optic discs. Qualitative grading was performed for dilation and tortuosity of the peripapillary vessels by 3 graders. Quantitative comparison was performed for peripapillary and inside disc vessel densities in nerve head (NH) and retinal peripapillary capillary (RPC) slabs ...

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    1-24 of 898 1 2 3 4 ... 36 37 38 »
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