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    1. The effect of contact lens wear on retinal spectral domain optical coherence tomography

      The effect of contact lens wear on retinal spectral domain optical coherence tomography

      Background This study assessed the impact of contact lens wear on retinal spectral domain optical coherence tomography (SD‐OCT) image quality and macular thickness measurements, among subjects with myopia. Methods This was a prospective study including 34 subjects (26.59 ± 3.19 years) with myopia or myopic astigmatism. Twelve were imaged wearing spherical soft contact lenses, eight non‐contact lens wearers were imaged with a plano soft contact lens, and 14 with significant astigmatism were fitted with a rigid gas permeable (RGP) contact lens. For each group of contact lens types, the average image quality index (Q‐index), and the ...

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    2. Non‐invasive multimodal imaging by integrating optical coherence tomography with autofluorescence imaging for dental applications

      Non‐invasive multimodal imaging by integrating optical coherence tomography with autofluorescence imaging for dental applications

      We report the development of an integrated multi‐functional imaging system capable of providing anatomical (optical coherence tomography, OCT), functional (OCT angiography, OCTA) and molecular imaging (light‐induced autofluorescence, LIAF) for in vivo dental applications. Blue excitation light (405 nm) was used for LIAF imaging, while the OCT was powered by a 1310 nm swept laser source. A red‐green‐blue (RGB) digital camera, with a 450 nm cut‐on broad‐band optical filter, was used for LIAF detection. The exciting light source and camera were integrated directly with the OCT scanning probe. The integrated system used two non‐invasive ...

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    3. Novel volumetric analysis for stent expansion after drug‐eluting stent implantation: An optical coherence tomography study

      Novel volumetric analysis for stent expansion after drug‐eluting stent implantation: An optical coherence tomography study

      Objectives To assess the clinical significance of a novel optical coherence tomography (OCT)‐derived volumetric parameter of stent expansion by comparing it with the conventional parameters in real‐world practice. Background The clinical significance of novel parameters in real‐world practice including longer and smaller stents remains to be elucidated. Methods A total of 226 de novo lesion treated with drug‐eluting stents in 208 consecutive patients were enrolled. Stent expansion was retrospectively assessed on the final OCT images after stent implantation. The novel parameter was the minimum expansion index (MEI) calculated using a novel algorithm that yields the ideal ...

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    4. Microvascular damage assessed by optical coherence tomography angiography for glaucoma diagnosis: a systematic review of the most discriminative regions

      Microvascular damage assessed by optical coherence tomography angiography for glaucoma diagnosis: a systematic review of the most discriminative regions

      A growing number of studies have reported a link between vascular damage and glaucoma based on optical coherence tomography angiography (OCTA) imaging. This multitude of studies focused on different regions of interest (ROIs) which offers the possibility to draw conclusions on the most discriminative locations to diagnose glaucoma. The objective of this work was to review and analyse the discriminative capacity of vascular density, retrieved from different ROIs, on differentiating healthy subjects from glaucoma patients. PubMed was used to perform a systematic review on the analysis of glaucomatous vascular damage using OCTA. All studies up to 21 April 2019 were ...

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    5. Comparison of post‐stent optical coherence tomography findings among three subtypes of calcified culprit plaques in patients with acute coronary syndrome

      Comparison of post‐stent optical coherence tomography findings among three subtypes of calcified culprit plaques in patients with acute coronary syndrome

      Objectives To compare the postprocedural optical coherence tomography (OCT) findings and in‐hospital outcomes among the three subtypes of calcified plaques: eruptive calcified nodules, superficial calcific sheet, and calcified protrusion. Background Recently, three subtypes of calcified culprit plaques were reported in patients with acute coronary syndrome (ACS). How these subtypes respond to stenting is unknown. Methods ACS patients with calcified plaque at the culprit lesion were selected from our database. OCT findings at baseline and after stent implantation were compared. Results In the final analysis, 87 cases were included. Preprocedural OCT showed eruptive calcified nodules in 19 (21.8%) cases ...

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    6. Retinal microvascular attenuation in mental cognitive impairment and Alzheimer's disease by optical coherence tomography angiography

      Retinal microvascular attenuation in mental cognitive impairment and Alzheimer's disease by optical coherence tomography angiography

      Purpose To explore regional variation of the macular microvasculature in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD), also to detect the association between retinal macular microvascular parameters and the progress of preclinical AD. Methods Prospective study of healthy controls, patients with MCI and patients with AD by using Optical coherence tomography angiography (OCT‐A). We quantified foveal avascular zone (FAZ) areas, densities of the superficial retinal capillary plexuses (SRCP) and deep retinal capillary plexuses (DRCP). The SRCP and DRCP were divided into inner (3 mm) and external (6 mm) annular rings, each containing four quadrants (SI ...

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    7. Three‐dimensional mapping of the attenuation coefficient in optical coherence tomography to enhance breast tissue micro‐architecture contrast

      Three‐dimensional mapping of the attenuation coefficient in optical coherence tomography to enhance breast tissue micro‐architecture contrast

      Effective intraoperative tumor margin assessment is needed to reduce re‐excision rates in breast‐conserving surgery (BCS). Mapping the attenuation coefficient in optical coherence tomography (OCT) throughout a sample to create an image (attenuation imaging) is one promising approach. For the first time, three‐dimensional OCT attenuation imaging of human breast tissue micro‐architecture using a wide‐field (up to ~45 × 45 × 3.5 mm) imaging system is demonstrated. Representative results from three mastectomy and one BCS specimen (from 31 specimens) are presented with co‐registered postoperative histology. Attenuation imaging is shown to provide substantially improved contrast over OCT, delineating ...

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    8. Optical Coherence Tomography in Diagnosis of Inflammatory Scalp Disorders

      Optical Coherence Tomography in Diagnosis of Inflammatory Scalp Disorders

      Background The common inflammatory scalp disorders share similar clinical manifestations, and patient work up require invasive, undesirable diagnostic procedures like biopsy to ensure correct diagnosis. Optical coherence tomography (OCT) is a noninvasive high‐resolution imaging modality that has found a valuable tool to assist in the diagnose and evaluation of different skin diseases. Objectives To describe the structural and vascular dynamic OCT (D‐OCT) findings of inflammatory scalp disorders including scalp psoriasis, seborrheic dermatitis and contact dermatitis, and to compare trichoscopy and OCT features. Methods Subjects with diagnosis of seborrheic dermatitis, psoriasis, or contact dermatitis were enrolled in this study ...

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    9. Impact of optical coherence tomography‐derived neointimal tissue morphology on development of very late in‐stent restenosis

      Impact of optical coherence tomography‐derived neointimal tissue morphology on development of very late in‐stent restenosis

      Objectives This study evaluated the progression of very late in‐stent restenosis (VL‐ISR) by analyzing four serial coronary angiography (CAG) images and its correlation with neointimal tissue characterization of the VL‐ISR lesions on optical coherence tomography (OCT). Background Recently, VL‐ISR is occasionally observed beyond a few years after drug‐eluting stents (DESs) implantation. Methods This study analyzed 50 VL‐ISR lesions after DES in which 4 serial CAGs over a period of 2 years, including at baseline procedure, 9 months after baseline procedure, 12 months before VL‐ISR, and at the time of VL‐ISR, were performed ...

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      Mentions: Kenichi Fujii
    10. Handheld volumetric manual compression‐based quantitative micro‐elastography

      Handheld volumetric manual compression‐based quantitative micro‐elastography

      Compression optical coherence elastography typically requires a mechanical actuator to impart a controlled uniform strain to the sample. However, for handheld scanning, this adds complexity to the design of the probe and the actuator stroke limits the amount of strain that can be applied. In this work, we present a new volumetric imaging approach that utilises bidirectional manual compression via the natural motion of the user's hand to induce strain to the sample, realising compact, actuator‐free, handheld compression optical coherence elastography. In this way, we are able to demonstrate rapid acquisition of three‐dimensional quantitative micro‐elastography (QME ...

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    11. Comparison of the Iowa Reference Algorithm to the Heidelberg Spectralis optical coherence tomography segmentation algorithm

      Comparison of the Iowa Reference Algorithm to the Heidelberg Spectralis optical coherence tomography segmentation algorithm

      For spectral‐domain optical coherence tomography (SD‐OCT) studies of neurodegeneration, it is important to understand how segmentation algorithms differ in retinal layer thickness measurements, segmentation error locations and the impact of manual correction. Using macular SD‐OCT images of frontotemporal degeneration patients and controls, we compare the individual and aggregate retinal layer thickness measurements provided by two commonly used algorithms, the Iowa Reference Algorithm and Heidelberg Spectralis, with manual correction of significant segmentation errors. We demonstrate small differences of most retinal layer thickness measurements between these algorithms. Outer sectors of the Early Treatment Diabetic Retinopathy Study grid require a ...

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    12. En‐face optical coherence tomography for the detection of cancer in prostatectomy specimens: quantitative analysis in 20 patients

      En‐face optical coherence tomography for the detection of cancer in prostatectomy specimens: quantitative analysis in 20 patients

      The increase histopathological evaluation of prostatectomy specimens rises the workload on pathologists. Automated histopathology systems, preferably directly on unstained specimens, would accelerate the pathology workflow. In this study, we investigate the potential of quantitative analysis of Optical Coherence Tomography (OCT) to separate benign from malignant prostate tissue automatically. Twenty fixated prostates were cut, from which 54 slices were scanned by OCT. Quantitative OCT metrics (attenuation coefficient, residue, goodness‐of‐fit) were compared for different tissue types, annotated on the histology slides. To avoid misclassification, the poor‐quality slides, and edges of annotations were excluded. Accurate registration of OCT data with ...

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    13. Optical coherence tomography as a noninvasive 3D real time imaging tool for the rapid evaluation of phenotypic variations in insect embryonic development

      Optical coherence tomography as a noninvasive 3D real time imaging tool for the rapid evaluation of phenotypic variations in insect embryonic development

      Noninvasive visualization of embryos at different development stages is crucial for the understanding of the basic developmental biology. It is therefore desirable to have an imaging tool capable of rapidly evaluating the effects of gene manipulation or genome editing in developing embryos for the studies of gene functions and genetic engineering. Here, we propose and demonstrate a novel use of optical coherence tomography (OCT) to noninvasively exam the embryonic development of the migratory locusts in real time with 3‐dimensional (3D) view capability. In particular, we obtain the sufficiently high spatial resolution tomographic 2D and 3D images of live locust ...

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    14. Applicability of optical coherence tomography in blue‐fronted parrots (Amazona aestiva)

      Applicability of optical coherence tomography in blue‐fronted parrots (Amazona aestiva)

      Objective Optical coherence tomography (OCT) measurement of adult blue‐fronted parrots ( Amazona aestiva ), free from infectious, inflammatory or neoplastic systemic diseases and from any ophthalmological illness, aim at its characterization, as well as to standardize the examination technique for the species. Procedure Pupillary dilation was achieved with rocuronium bromide (5 mg/mL) at 0, 2, 15, 17, 30, and 32 minutes. The animals were sedated with midazolam maleate (0.5 mg/kg/IM) and anesthetized with propofol (5.0 mg/kg/IV). Measurements were made to evaluate the thickness of the total retina (TR), sensorineural retinal (SR), and ganglion cell ...

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    15. Novel, vessel anatomy adjusting drug‐coated balloon—Preclinical evaluation in peripheral porcine arteries

      Novel, vessel anatomy adjusting drug‐coated balloon—Preclinical evaluation in peripheral porcine arteries

      Background The diameter of balloons or stents is selected according to the estimated reference vessel diameter and do not adapt to the vessel anatomy. The aim of the present preclinical studies was to investigate a novel, vessel anatomy adjusting hypercompliant drug‐coated balloon catheter (HCDCB). Methods Hypercompliant balloon membranes were coated in a constricted state with high drug density. Drug adherence was investigated in vitro, transfer to the porcine peripheral arteries and longitudinal distribution in vivo. In young domestic swine, neointimal proliferation was induced by vessel overstretch and continuous irritation by permanent stents. Uncoated hypercompliant balloons (HCB), and standard uncoated ...

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    16. Fundus autofluorescence, spectral‐domain optical coherence tomography, and histology correlations in a Stargardt disease mouse model

      Fundus autofluorescence, spectral‐domain optical coherence tomography, and histology correlations in a Stargardt disease mouse model

      Stargardt disease (STGD1), known as inherited retinal dystrophy, is caused by ABCA4 mutations. The pigmented Abca4 −/− mouse strain only reflects the early stage of STGD1 since it is devoid of retinal degeneration. This blue light‐illuminated pigmented Abca4 −/− mouse model presented retinal pigment epithelium (RPE) and photoreceptor degeneration which was similar to the advanced STGD1 phenotype. In contrast, wild‐type mice showed no RPE degeneration after blue light illumination. In Abca4 −/− mice, the acute blue light diminished the mean autofluorescence (AF) intensity in both fundus short‐wavelength autofluorescence (SW‐AF) and near‐infrared autofluorescence (NIR‐AF) modalities correlating with reduced ...

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    17. Optical coherence tomography‐defined plaque vulnerability in relation to functional stenosis severity stratified by fractional flow reserve and quantitative flow ratio

      Optical coherence tomography‐defined plaque vulnerability in relation to functional stenosis severity stratified by fractional flow reserve and quantitative flow ratio

      Objectives We sought to investigate that the quantitative flow ratio (QFR) might be associated with optical coherence tomography (OCT)‐defined plaque vulnerability. Background Both functional stenosis severity and plaque instability are related to adverse clinical outcomes in patients with coronary artery disease. Recent studies have shown an association between physiological stenosis severity and the presence of thin‐cap fibroatheroma (TCFA). Measurement of QFR is a novel method for rapid computational estimation of fractional flow reserve (FFR). Methods We investigated 327 de novo intermediate‐to‐severe coronary lesions in 295 stable patients who underwent OCT, FFR, and QFR computation. The lesions ...

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    18. Multimodal imaging characteristics of congenital grouped hyper‐ and hypo‐pigmented fundus lesions

      Multimodal imaging characteristics of congenital grouped hyper‐ and hypo‐pigmented fundus lesions

      Background The imaging characteristics of congenital grouped pigmentation of the retinal pigment epithelium (CGP‐RPE) and its non‐pigmented variant – grouped congenital albinotic retinal pigment epithelial spots (GCARPES) are poorly defined in the literature. Our case series reports their multimodal imaging characteristics across a spectrum of presentations. Methods A retrospective review of patient records was conducted on patients seen at the Centre for Eye Health between January and December 2016. The multimodal imaging findings across four cases is described using optical coherence tomography (OCT), infrared imaging, ultra‐widefield imaging, fundus photography and fundus autofluorescence (FAF). Results Case 1 is a ...

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    19. Plasmonic Copper Sulfide Nanoparticles Enable Dark Contrast in Optical Coherence Tomography

      Plasmonic Copper Sulfide Nanoparticles Enable Dark Contrast in Optical Coherence Tomography

      Optical coherence tomography (OCT) is an imaging technique affording noninvasive optical biopsies. Like for other imaging techniques, the use of dedicated contrast agents helps better discerning biological features of interest during the clinical practice. Although bright OCT contrast agents have been developed, no dark counterpart has been proposed yet. Herein, plasmonic copper sulfide nanoparticles as the first OCT dark contrast agents working in the second optical transparency window are reported. These nanoparticles virtually possess no light scattering capabilities at the OCT working wavelength (≈1300 nm); thus, they exclusively absorb the probing light, which in turn results in dark contrast. The ...

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      Mentions: Fernando Alfonso
    20. Use of Optical Coherence Tomography (OCT) in Aesthetic Skin Assessment—A Short Review

      Use of Optical Coherence Tomography (OCT) in Aesthetic Skin Assessment—A Short Review

      Assessments of non‐surgical office‐based aesthetic treatments' efficacy including lasers are mostly based on subjective evaluation of clinical photography. Accumulating evidence suggest that non‐invasive skin imaging such as optical coherence tomography (OCT) can be effectively used to assess not only the skin surface but also the underlying epidermis and dermis, providing objective and clinically relevant data. In this review, we highlight the potential of OCT imaging for the aesthetic medicine field along with OCT measurement parameters and their clinical relevance to healthy and pathological skin conditions.

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    21. Intravascular lithotripsy to treat an underexpanded coronary stent: 4‐Month angiographic and OCT follow‐up

      Intravascular lithotripsy to treat an underexpanded coronary stent: 4‐Month angiographic and OCT follow‐up

      We report the case of a 79‐year‐old man with stable angina who underwent percutaneous coronary intervention to a severe and calcified left circumflex lesion. Despite extensive preparation of the lesion with high‐pressure balloon predilatation and rotablation, the implanted stent was grossly underexpanded and failed to respond to high‐pressure balloon postdilatation. The patient was readmitted 6 weeks later for intravascular lithotripsy that resulted in excellent stent expansion. Coronary angiography with optical coherence tomography 4 months later revealed sustained acute lumen gain with no evidence of stent recoil or in‐stent restenosis.

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    22. Correlation between new OCT parameters and metamorphopsia in advanced stages of epiretinal membranes

      Correlation between new OCT parameters and metamorphopsia in advanced stages of epiretinal membranes

      Purpose To correlate metamorphopsia provided by M‐CHARTS and ectopic inner foveal layers (EIFL) or ‘central bouquet’ abnormality (CBA) in patients with advanced stages of epiretinal membrane (ERM) following the novel Optical Coherence Tomography (OCT)‐based grading scheme. Methods In 60 eyes of 57 patients affected by ERM (stages 3 and 4), the degree of metamorphopsia using the M‐CHARTS was evaluated (M‐SCORE) and correlated with EIFL, CBA and central foveal thickness (CFT) as measured on OCT scans. Results A total of 37 and 23 eyes were diagnosed having ERM stages 3 and 4, respectively. Mean vertical and horizontal ...

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    23. Absorb bioresorbable vascular scaffold outcomes following implantation with routine intravascular imaging guidance

      Absorb bioresorbable vascular scaffold outcomes following implantation with routine intravascular imaging guidance

      Objectives We sought to describe the outcomes of BVS use from a single‐center experience in which scaffold implantation was guided by intravascular imaging (ultrasound and/or optical coherence tomography) to identify and treat mechanical factors potentially related to BVS failure. Background The Absorb bioresorbable vascular scaffold (BVS) has been associated with an unexpectedly high incidence of thrombosis. Methods Between 11/2014 and 10/2016, 100 patients were treated with BVS. Intravascular imaging assessment before and after BVS implantation was performed in all cases. Results Mean age was 58.1 years; 88% were male, 31% had diabetes, and 28% presented ...

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