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    1. Investigation of the variability of anterior chamber scan protocol with Cirrus high definition optical coherence tomography

      Investigation of the variability of anterior chamber scan protocol with Cirrus high definition optical coherence tomography

      Importance The evaluation of anterior chamber scan (ACS) of Cirrus optical coherence tomography (OCT) for routine clinical use Background To assess the variability of anterior chamber angle (ACA) measurements using the ACS Design Cross-sectional observational study Participants Forty subjects aged 40-80 years Methods One randomly selected eye from 40 subjects was imaged with Cirrus OCT (model 5000, Carl Zeiss Meditec, Dublin, CA) by two different operators (expert vs non-expert) with a 15-minute interval for inter- and intra-observer variability of image acquisition. For image grading, the angle opening distance (AOD750) and the trabecular iris space area (TISA750) of nasal and temporal ...

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    2. Use of optical coherence tomography for the diagnosis of preclinical lesions of circumscribed palmar hypokeratosis

      Use of optical coherence tomography for the diagnosis of preclinical lesions of circumscribed palmar hypokeratosis

      Circumscribed hypokeratosis of palms and soles is a rare dermatosis, usually affecting women. Diagnosis is mainly based on the clinical characteristics, including the clinical appearance and anatomical site of the skin lesions and on the demographic features of the affected patients, usually middle-aged to elderly women. Skin biopsy may be performed to confirm clinical diagnosis. Optical coherence tomography (OCT) is a technique that has been undergone substantial development in dermatology in recent years, and its use in clinical practice has been growing progressively. Several dermatological conditions have been studied with this tool, but to our knowledge, it has not been ...

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    3. A computer aided diagnostic system for detecting diabetic retinopathy in optical coherence tomography images

      A computer aided diagnostic system for detecting diabetic retinopathy in optical coherence tomography images

      urpose Detection (diagnosis) of diabetic retinopathy (DR) in optical coherence tomography (OCT) images for patients with type 2 diabetes, but almost clinically normal retina appearances. Methods The proposed computer-aided diagnostic (CAD) system detects the DR in three steps: (i) localizing and segmenting 12 distinct retinal layers on the OCT image; (ii) deriving features of the segmented layers, and (iii) learning most discriminative features and classifying each subject as normal or diabetic. To localise and segment the retinal layers, signals (intensities) of the OCT image are described with a joint Markov-Gibbs random field (MGRF) model of intensities and shape descriptors. Each ...

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    4. Impact of an optical coherence tomography guided approach in acute coronary syndromes: A propensity matched analysis from the international FORMIDABLE-CARDIOGROUP IV and USZ registry

      Impact of an optical coherence tomography guided approach in acute coronary syndromes: A propensity matched analysis from the international FORMIDABLE-CARDIOGROUP IV and USZ registry

      Aim. To determine the potential clinical impact of OCT (Optical Coherence Tomography) during primary percutaneous coronary intervention in patients presenting with ACS (Acute Coronary Syndrome). Methods and Results. FORMIDABLE is a multicentre retrospective registry enrolling all patients presenting with ACS and treated with an OCT-guided approach, while the USZ registry enrolled patients treated with a standard angiography guided approach. Multivariate adjustment was performed via a propensity score matching. The number stents useds was the primary outcome, while the incidence of MACE (a composite of death, myocardial infarction, target vessel revascularization, and stent thrombosis) was the secondary endpoint. A total of ...

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    5. Measurement of lacrimal punctum using spectralis domain anterior optical coherence tomography

      Measurement of lacrimal punctum using spectralis domain anterior optical coherence tomography

      Purpose Anterior segment optical coherence tomography (AS-OCT) was used to image the lacrimal punctum and establish normal punctal parameters including the tear volume inside the punctum. Methods This study included totally 67 eyes from 38 normal subjects. Punctal parameters and tear meniscus height (TMH) were measured using spectralis OCT anterior-segment scans. Outer punctal diameter (OPD), punctal depth, tear well diameter (TWD), tear well depth, punctal reserve (PR) and lower eyelid TMH were assessed. Authors defined a ‘tear well’ as a pool of standing tears in the punctum. Punctal reserve was defined as the difference between punctal depth and tear well ...

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    6. Comparative study of presurgical skin infiltration depth measurements of melanocytic lesions with OCT and high frequency ultrasound

      Comparative study of presurgical skin infiltration depth measurements of melanocytic lesions with OCT and high frequency ultrasound

      A reliable, fast, and non-invasive determination of melanoma thickness in vivo is highly desirable for clinical dermatology as it may facilitate the identification of surgical melanoma margins, determine if a sentinel node biopsy should be performed or not, and reduce the number of surgical interventions for patients. In this work, optical coherence tomography (OCT) and high frequency ultrasound (HFUS) are evaluated for quantitative in vivo preoperative assessment of the skin infiltration depth of melanocytic tissue. Both methods allow non-invasive imaging of skin at similar axial resolution. Comparison with the Breslow lesion thickness obtained from histopathology revealed that OCT is slightly ...

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    7. A useful way to develop effective in vivo skin optical clearing agents

      A useful way to develop effective in vivo skin optical clearing agents

      Skin optical clearing has shown tremendous potential in improving various optical imaging performances, but there is some certain blindness in screening out high-efficiency in vivo optical clearing methods. In this work, three optical clearing agents: sucrose (Suc), fructose (Fruc) and PEG-400 (PEG), and two chemical penetration enhancers: propylene glycol (PG) and thiazone (Thiaz) were used. PEG was firstly mixed with the two penetration enhancers, respectively, and then mixed with Fruc and Suc, respectively, to obtain six kinds of skin optical clearing agents (SOCAs). Optical coherence tomography angiography was applied to monitor SOCAs-induced changes in imaging performances, skin optical properties, refractive ...

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    8. Effect of different lubricant eye gels on tear film thickness as measured with ultrahigh-resolution optical coherence tomography

      Effect of different lubricant eye gels on tear film thickness as measured with ultrahigh-resolution optical coherence tomography

      Purpose To compare the effect of a single drop of different lubricant eye gels on tear film thickness (TFT) as measured with ultrahigh-resolution optical coherence tomography (UHR-OCT) in patients with mild-to-moderate dry eye disease (DED). Methods The study followed a randomized, single-masked, observer-blinded parallel group design. Patients received a single dose of either unpreserved trehalose 3% + hyaluronic acid 0.15% (TH), hyaluronic acid 0.2% (HA) or polyethylene glycol 0.4% + propylene glycol 0.3% (PP) eye drops. In total, 60 patients were included and TFT was measured using a custom-built UHR-OCT system. Results The mean TFT at baseline was ...

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    9. Modern trends in biophotonics for clinical diagnosis and therapy to solve unmet clinical needs

      Modern trends in biophotonics for clinical diagnosis and therapy to solve unmet clinical needs

      This contribution covers recent original research papers in the biophotonics field. The content is organized into main techniques such as multiphoton microscopy, Raman spectroscopy, infrared spectroscopy, optical coherence tomography and photoacoustic tomography, and their applications in the context of fluid, cell, tissue and skin diagnostics. Special attention is paid to vascular and blood flow diagnostics, photothermal and photodynamic therapy, tissue therapy, cell characterization, and biosensors for biomarker detection

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    10. Morphomechanics of dermis-A method for non-destructive testing of collagenous tissues

      Morphomechanics of dermis-A method for non-destructive testing of collagenous tissues

      Background Collagenous tissues store, transmit and dissipate elastic energy during mechanical deformation. In skin, mechanical energy is stored during loading and then is dissipated, which protects skin from mechanical failure. Thus, energy storage (elastic properties) and dissipation (viscous properties) are important characteristics of extracellular matrices (ECMs) that support the cyclic loading of ECMs without tissue failure. Methods Uniaxial stress-strain measurements on decellularized human dermis have been made and compared to results of a non-destructive technique involving optical coherence tomography (OCT) combined with vibrational analysis. In addition, Poisson's ratio has been determined for tensile deformation of decellularized dermis. Results The ...

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      Mentions: Mark C. Pierce
    11. Morphomechanics of dermis-A method for non-destructive testing of collagenous tissues

      Morphomechanics of dermis-A method for non-destructive testing of collagenous tissues

      Background Collagenous tissues store, transmit and dissipate elastic energy during mechanical deformation. In skin, mechanical energy is stored during loading and then is dissipated, which protects skin from mechanical failure. Thus, energy storage (elastic properties) and dissipation (viscous properties) are important characteristics of extracellular matrices (ECMs) that support the cyclic loading of ECMs without tissue failure. Methods Uniaxial stress-strain measurements on decellularized human dermis have been made and compared to results of a non-destructive technique involving optical coherence tomography (OCT) combined with vibrational analysis. In addition, Poisson's ratio has been determined for tensile deformation of decellularized dermis. Results The ...

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    12. Fractional laser-assisted drug uptake: Impact of time-related topical application to achieve enhanced delivery

      Fractional laser-assisted drug uptake: Impact of time-related topical application to achieve enhanced delivery

      Background and Objective Ablative fractional laser (AFXL) is acknowledged to increase uptake of topically applied agents in skin. AFXL channels gradually close over time, which may impair this capability. The time frame for applying a drug after AFXL exposure remains to be established. The aim of this study, was to investigate the importance of time-related topical application after AFXL exposure and to relate resultant uptake in skin with AFXL channel morphology and skin integrity. Study Design/Materials and Methods Buttock skin of healthy volunteers ( n  = 11) was exposed to 10,600 nm fractional CO 2 laser using 5% density, 120 ...

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      Mentions: Mette Mogensen
    13. Predicting the intereye asymmetry in functional and structural damage in glaucoma using automated pupillography

      Predicting the intereye asymmetry in functional and structural damage in glaucoma using automated pupillography

      Purpose To predict the intereye asymmetry in functional (mean deviation, MD on visual field, VF) and structural (retinal nerve fibre layer, RNFL and ganglion cell complex, GCC thickness on spectral domain optical coherence tomography, SDOCT) measurements in glaucoma using the automated pupillography parameters. Methods Fifty-nine subjects with a diagnosis of either glaucoma or glaucoma suspect underwent automated pupillography along with VF and SDOCT examinations. Association between pupillography and the absolute intereye difference in MD, RNFL and GCC measurements was evaluated using regression analysis after accounting for the multicollinearity. Results Univariate regression analysis showed statistically significant associations (p < 0.05) between ...

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    14. Dynamic nanomechanical analysis of the vocal fold structure in excised larynges

      Dynamic nanomechanical analysis of the vocal fold structure in excised larynges

      Objectives/Hypothesis Quantification of clinical outcomes after vocal fold (VF) interventions is challenging with current technology. High-speed digital imaging and optical coherence tomography (OCT) of excised larynges assess intact laryngeal function, but do not provide critical biomechanical information. We developed a protocol to quantify tissue properties in intact, excised VFs using dynamic nanomechanical analysis (nano-DMA) to obtain precise biomechanical properties in the micrometer scale. Study Design Experimental animal study. Methods Three pig larynges were bisected in the sagittal plane, maintaining an intact anterior commissure, and subjected to nano-DMA at nine locations with a 250-μm flat-tip punch and frequency sweep ...

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    15. Melanoma diagnosis may be a pitfall for optical coherence tomography assessment of equivocal amelanotic or hypomelanotic skin lesions

      Melanoma diagnosis may be a pitfall for optical coherence tomography assessment of equivocal amelanotic or hypomelanotic skin lesions

      melanotic and hypomelanotic skin lesions can be difficult to diagnose clinically and dermoscopically. 1-3 Evidence is emerging that optical coherence tomography (OCT) can detect superficial basal cell carcinoma (sBCC) with good sensitivity (79-95.7%) and specificity (75.3-96%). 4 Given that sBCC is a common problem 4 , and that it may be treated noninvasively 5 , the potential benefits from using OCT as an adjunct to clinical diagnosis are high. However, if OCT is used without histopathological confirmation in this setting, there is a risk that more clinically aggressive malignant pathology, such as amelanotic /hypomelanotic melanoma (AHM), may be misdiagnosed and ...

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    16. Fractal analysis of en face tomographic images obtained with full field optical coherence tomography

      Fractal analysis of en face tomographic images obtained with full field optical coherence tomography

      The quantitative modeling of the imaging signal of pathological areas and healthy areas is necessary to improve the specificity of diagnosis with tomographic en face images obtained with full field optical coherence tomography (FFOCT). In this work, we propose to use the depth-resolved change in the fractal parameter as a quantitative specific biomarker of the stages of disease. The idea is based on the fact that tissue is a random medium and only statistical parameters that characterize tissue structure are appropriate. We successfully relate the imaging signal in FFOCT to the tissue structure in terms of the scattering function and ...

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      Mentions: Wanrong Gao
    17. Impact of retinal pigment epithelium pathology on spectral-domain optical coherence tomography-derived macular thickness and volume metrics and their intersession repeatability

      Impact of retinal pigment epithelium pathology on spectral-domain optical coherence tomography-derived macular thickness and volume metrics and their intersession repeatability

      Background To determine the impact of retinal pigment epithelium (RPE) pathology on intersession repeatability of retinal thickness and volume metrics derived from Spectralis spectral-domain optical coherence tomography (SD-OCT). Design Prospective cross-sectional single centre study. Participants 56 eyes of 56 subjects were divided into 3 groups: (A) normal RPE band (25 eyes), (B) RPE elevation: macular soft drusen (13 eyes) and (C) RPE attenuation: geographic atrophy or inherited retinal diseases (18 eyes). Methods Each subject underwent three consecutive follow-up macular raster scans (61 B-scans at 119 micron separation) at 1-month intervals. Main outcome measures Retinal thicknesses and volumes for each zone ...

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    18. A method to study the hemodynamics of chicken embryo's aortic arches using optical coherence tomography

      A method to study the hemodynamics of chicken embryo's aortic arches using optical coherence tomography

      Congenital cardiovascular defects are the leading cause of birth defect related death. It has been hypothesized that fluid mechanical forces of embryonic blood flow affect cardiovascular development and play a role in congenital malformations. Studies in small animal embryos can improve our understanding of congenital malformations and can lead to better treatment. We present a feasibility study in which high-resolution optical coherence tomography (OCT) and computational fluid dynamics (CFD) are combined to provide quantitative analysis of the embryonic flow mechanics and the associated anatomy in a small animal model.

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    19. Comparison of corneal measurements in keratoconus using swept-source optical coherence tomography and combined Placido–Scheimpflug imaging

      Comparison of corneal measurements in keratoconus using swept-source optical coherence tomography and combined Placido–Scheimpflug imaging

      Purpose The aim of this study was to provide a comprehensive comparison of reliability of corneal topographic measurements in keratoconic eyes using swept-source optical coherence tomography (OCT) and a combined Placido–Scheimpflug imaging. Methods A total of 30 eyes of 30 patients were included. The mean age was 31.2 ± 8.4 years. Two consecutive topographic measurements were obtained for one eye of each patient using swept-source OCT (CASIA) and combined Placido–Scheimpflug imaging (TMS-5). Test–retest reliability of CASIA and TMS-5 measurements including central corneal thickness (CCT) and thinnest corneal thickness (TCT), keratometry at steep (Ks) and flat (Kf ...

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      Mentions: Marco Yu
    20. A sloped piecemeal Gaussian model for characterising foveal pit shape

      A sloped piecemeal Gaussian model for characterising foveal pit shape

      Purpose High-quality optical coherence tomography (OCT) macular scans make it possible to distinguish a range of normal and diseased states by characterising foveal pit shape. Existing mathematical models lack the flexibility to capture all known pit variations and thus characterise the pit with limited accuracy. This study aimed to develop a new model that provides a more robust characterisation of individual foveal pit variations. Methods A Sloped Piecemeal Gaussian (SPG) model, consisting of a linear combination of a tilted line and a piecemeal Gaussian function (two halves of a Gaussian connected by a separate straight line), was developed to fit ...

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    1-24 of 636 1 2 3 4 ... 25 26 27 »
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