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    1. Optical Coherence Tomography Findings in Patients with Bipolar Disorder

      Optical Coherence Tomography Findings in Patients with Bipolar Disorder

      Background Research in bipolar disorder suggests the presence of structural brain abnormalities. It is not clear whether these findings are trait markers or operate with the onset and progress with disease severity and duration. Optical coherence tomography (OCT) is a non-invasive technique that detects degenerative changes in the retina reflecting brain degeneration. This study aimed at detecting these changes and relating them to disease severity and clinical characteristics. Methods A case-control study conducted in Psychiatry and Addiction Medicine hospital, Faculty of Medicine at Cairo University. Forty inpatients with bipolar disorder -according to the 4 th edition of the Diagnostic and ...

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    2. Assessment of enamel cracks at adhesive cavosurface margin using three-dimensional swept-source optical coherence tomography

      Assessment of enamel cracks at adhesive cavosurface margin using three-dimensional swept-source optical coherence tomography

      Objectives Swept-source optical coherence tomography (SS-OCT) can construct cross-sectional images of internal biological structures. The aim of this study was to evaluate enamel cracks at the cavosurface margin of composite restorations using SS-OCT. Methods Bowl-shaped cavities were prepared at two locations (mid-coronal and cervical regions) on the enamel surface of 60 bovine teeth. Half of the cavities (30) were treated with phosphoric acid gel. A two-step self-etch adhesive (Clearfil SE Bond) was applied to all cavities and a flowable composite was placed in bulk. After 7 days in water at 37 °C, three-dimensional (3D) images of the specimens were obtained ...

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    3. Discriminating hidden bruises in loquat by attenuation coefficients estimated from optical coherence tomography images

      Discriminating hidden bruises in loquat by attenuation coefficients estimated from optical coherence tomography images

      Hidden bruising is considered as one of the difficulties during loquat quality control, which has made an impact on postharvest quality and storability. Optical coherence tomography (OCT) is used as a non-destructive method that acquires 2D images of the sub-surface structure of the loquat. After OCT image processing, the attenuation coefficients ( μ t ) of the regions of interests are fitted to quantitatively analyze the characteristics of loquat tissue through using a confocal signal scattering model from OCT A-scan signals. In this experiment, a total of 60 loquat samples are investigated, with the non-bruised tissue having a large μ t with a mean ...

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    4. Emerging Applications of Optical Coherence Tomography in Pediatric Optic Neuropathies

      Emerging Applications of Optical Coherence Tomography in Pediatric Optic Neuropathies

      Limited cooperation and attention span often lead to poorly reliable assessments of visual acuity and visual fields in children, making diagnosis and monitoring of pediatric optic neuropathies challenging. As a noninvasive imaging modality, optical coherence tomography (OCT) could offer particular utility in this patient population. OCT provides high-resolution characterization of the optic nerve head, peripapillary retinal nerve fiber layer, and cellular layers of the macula, all of which can be used to assess the severity of optic nerve disease qualitatively and quantitatively. Application of OCT to pediatric patients has been limited by technical factors and lack of pediatric normative databases ...

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      Mentions: Duke University
    5. Agreement between OCT Leakage and Fluorescein Angiography to Identify Sites of Alteration of the Blood–Retinal Barrier in Diabetes

      Agreement between OCT Leakage and Fluorescein Angiography to Identify Sites of Alteration of the Blood–Retinal Barrier in Diabetes

      Purpose To compare the location of the sites of lower reflectivity, as determined by OCT leakage using spectral domain (SD)-OCT, with sites of fluorescein leakage identified by fluorescein angiography (FA) in eyes with diabetic retinopathy. Design Prospective consecutive case series. Participants Fifty-two eyes from 28 patients with type 2 diabetes and presence of nonproliferative diabetic retinopathy. Methods All patients were imaged with FA and SD-OCT (Angioplex, Carl Zeiss Meditec, Inc). All FA images were analyzed by 2 experienced graders, and the area surrounding well-defined sites of leakage was outlined by the graders. The SD-OCT scans were processed using OCT ...

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    6. Change in vault during scleral lens trials assessed with anterior segment optical coherence tomography

      Change in vault during scleral lens trials assessed with anterior segment optical coherence tomography

      Purpose To assess the change in vault during scleral lens fitting with anterior segment optical coherence tomography (AS-OCT). Methods This study comprised of patients who had AS-OCT performed after 1 h and 4 h of scleral lens wear (PROSE, prosthetic replacement of the ocular surface ecosystem, Boston Foundation for Sight, Needham Heights, MA, USA). Vault was measured on AS-OCT as the distance between the front surface of the cornea in the center and the back surface of the scleral lens. Results Fifty eyes of 41 patients were analyzed. The main indications for scleral lens trial were ectasia (keratoconus, post surgery ...

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    7. Optical coherence tomography angiography of the retina and choroid; current applications and future directions

      Optical coherence tomography angiography of the retina and choroid; current applications and future directions

      Dye-based angiography has been the standard of care for the diagnosis of retinal, choroidal and optic nerve vascular disorders for a long period of time. Since its introduction in 1961, angiography techniques and instrumentation have remarkably improved. 1 These advancements include, but are not limited to, the development of confocal scanning laser ophthalmoscopy, digital angiography, and wide-field imaging techniques. However, dye-based angiography remains a time-consuming, invasive procedure that requires skilled photographers. In addition, the images have limited depth resolution. Recently, a novel imaging strategy, optical coherence tomography angiography (OCTA) has been introduced. OCTA is a noninvasive modality for vascular mapping ...

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      Mentions: UCLA
    8. Massively parallel data processing for quantitative total flow imaging with optical coherence microscopy and tomography

      Massively parallel data processing for quantitative total flow imaging with optical coherence microscopy and tomography

      We present an application of massively parallel processing of quantitative flow measurements data acquired using spectral optical coherence microscopy (SOCM). The need for massive signal processing of these particular datasets have been a major hurdle for many applications based on SOCM. In view of this difficulty, we implemented and adapted quantitative total flow estimation algorithms on graphics processing units (GPU) and achieved a 150 fold reduction in processing time when compared to a former CPU implementation. As SOCM constitutes the microscopy counterpart to spectral optical coherence tomography (SOCT), the developed processing procedure can be applied to both imaging modalities. We ...

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    9. 3-D surface profile measurement using spectral interferometry based on continuous wavelet transform

      3-D surface profile measurement using spectral interferometry based on continuous wavelet transform

      This study proposes a signal analysis technique that uses continuous wavelet transform for signal processing in a spectral domain optical coherence tomography system. Our method enables us to calculate the optical path difference simply by taking advantage of the fact that the product of the phase and wavelength becomes constant. Experimental results obtained using a pair of gauge blocks with a thickness difference of 40 µm confirm that the repetitive measurement accuracy was 65.1 nm. A demonstration of the three-dimensional surface profile measurement indicates that the rms measurement error is 0.17 µm.

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      Mentions: Osami Sasaki
    10. Role of high resolution optical coherence tomography in diagnosing ocular surface squamous neoplasia with coexisting ocular surface diseases

      Role of high resolution optical coherence tomography in diagnosing ocular surface squamous neoplasia with coexisting ocular surface diseases

      Purpose Coexistence of an ocular surface disease can mask the typical features of ocular surface squamous neoplasia (OSSN). The purpose of this study was to evaluate high resolution optical coherence tomography (HR-OCT) as an adjunct in the detection and differentiation of OSSN within coexisting ocular surface pathologies. Methods Retrospective study of 16 patients with ocular surface disease and lesions suspicious for OSSN that were evaluated with HR-OCT. HR-OCT images of the lesions were taken to look for evidence of OSSN. Biopsies were performed in all cases, and the HR-OCT findings were compared to the histological results. Results Of the 16 ...

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    11. Combined spectral-domain optical coherence tomography and hyperspectral imaging applied for tissue analysis: preliminary results

      Combined spectral-domain optical coherence tomography and hyperspectral imaging applied for tissue analysis: preliminary results

      In recent years many optoelectronic techniques have been developed for improvement and the development of devices for tissue analysis. Spectral-Domain Optical Coherence Tomography (SD-OCT) is a new medical interferometric imaging modality that provides depth resolved tissue structure information with resolution in the μm range. However, SD-OCT has its own limitations and cannot offer the biochemical information of the tissue. These data can be obtained with hyperspectral imaging, a non-invasive, sensitive and real time technique. In the present study we have combined Spectral-Domain Optical Coherence Tomography (SD-OCT) with Hyperspectral imaging (HSI) for tissue analysis. The Spectral-Domain Optical Coherence Tomography (SD-OCT) and ...

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    12. One-year follow-up optical coherence tomography after endovascular treatment with a new-generation zotarolimus-eluting stent for chronic mesenteric ischemia

      One-year follow-up optical coherence tomography after endovascular treatment with a new-generation zotarolimus-eluting stent for chronic mesenteric ischemia

      A 62-year-old man experienced lower abdominal pain triggered by a hypotensive episode during hemodialysis for end-stage renal failure. Computed tomography scan and subsequent angiography revealed a significant calcified stenosis at the proximal part of inferior mesenteric artery (IMA) ( Fig. 1 A-C). Abdominal angina was diagnosed and his symptoms were reproduced during intentional hypotension induced by intravenous administration of calcium channel blocker with drop in the Pd/Pa within the IMA lesion from 0.90 to 0.80. In addition, the balloon occlusion during endovascular treatment as described below also reproduced his symptoms. Pre-procedural optical coherence tomography (OCT) showed a lipid-rich ...

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      Mentions: Yusuke Fujino
    13. Optical coherence tomography angiography of the peripapillary retina and optic nerve head in dominant optic atrophy

      Optical coherence tomography angiography of the peripapillary retina and optic nerve head in dominant optic atrophy

      Peripapillar and nerve head vessel density (VD) was measured in 10 patients affected by Dominant optic atrophy (DOA) using optical coherence tomography angiography (OCT-A) and compared to the measurements of 15 age- and gender-matched controls. DOA patients showed VD reduction, mostly in the temporal and inferotemporal peripapillary sectors, according to the preferential involvement of the papillomacular bundle. Despite poor best-corrected visual acuity (BCVA), OCT-A revealed good repeatability. VD correlated with functional (mean deviation of visual field and BCVA) and structural (retinal nerve fiber layer thickness) parameters and could be a non-invasive, quantitative tool for the monitoring of the disease and ...

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    14. The REMEDEE-OCT Study : An Evaluation of the Bioengineered COMBO Dual-Therapy CD34 Antibody–Covered Sirolimus-Eluting Coronary Stent Compared With a Cobalt-Chromium Everolimus-Eluting Stent in Patients With Acute Coronary Syndromes: Insights From Optical

      The REMEDEE-OCT Study : An Evaluation of the Bioengineered COMBO Dual-Therapy CD34 Antibody–Covered Sirolimus-Eluting Coronary Stent Compared With a Cobalt-Chromium Everolimus-Eluting Stent in Patients With Acute Coronary Syndromes: Insights From Optical

      Objectives The aim of the present study was to evaluate vascular healing of the bioengineered COMBO Dual Therapy Stent compared with a cobalt-chromium (CoCr) everolimus-eluting stent (EES) as assessed by optical coherence tomography in patients with acute coronary syndromes. Background CD34+ cells promote endothelial repair after vascular injury. The bioengineered COMBO Dual Therapy Stent combines CD34+ cell–capturing technology with abluminal sirolimus release, but more data from clinical studies evaluating the vascular response are needed. Methods In a prospective randomized multicenter clinical trial, 60 patients with acute coronary syndromes were randomized 1:1 to COMBO or CoCr EES implantation. The ...

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    15. Imaging Resin Infiltration into Non-Cavitated Carious Lesions by Optical Coherence Tomography

      Imaging Resin Infiltration into Non-Cavitated Carious Lesions by Optical Coherence Tomography

      Objectives Visualisation of the etching process and resin penetration at white spot carious lesions by spectral domain optical coherence tomography (SD-OCT). Materials and methods The non-cavitated carious lesions (ICDAS code 2) of four visually preselected extracted human molars and premolars were verified as enamel lesions by micro computed tomography (μCT). One region of interest (ROI) per tooth was marked by two drill-holes in occlusal-cervical direction. The lesions were imaged by SD-OCT. Lesions were infiltrated (Icon, DMG) according to the manufacturer’s instructions. During each treatment step and after light curing of the infiltrant, the ROIs were imaged again by SD-OCT ...

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    16. Deep Learning Is Effective for Classifying Normal versus Age-Related Macular Degeneration Optical Coherence Tomography Images

      Deep Learning Is Effective for Classifying Normal versus Age-Related Macular Degeneration Optical Coherence Tomography Images

      Purpose The advent of electronic medical records (EMRs) with large electronic imaging databases along with advances in deep neural networks with machine learning has provided a unique opportunity to achieve milestones in automated image analysis. Optical coherence tomography (OCT) is the most common imaging modality in ophthalmology and represents a dense and rich data set when combined with labels derived from the EMR. We sought to determine whether deep learning could be utilized to distinguish normal OCT images from images from patients with age-related macular degeneration (AMD). Design EMR and OCT database study. Subjects Normal and AMD patients who underwent ...

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    17. Accuracy of computed tomography angiography to identify thin-cap fibroatheroma detected by optical coherence tomography

      Accuracy of computed tomography angiography to identify thin-cap fibroatheroma detected by optical coherence tomography

      Background Thin-cap fibroatheroma (TCFA) is assumed to cause acute coronary syndromes. Objective To compare the accuracy of different models for diagnosing TCFA using parameters derived by CT, validated against optical coherence tomography (OCT). Methods One hundred twenty-nine plaques in 106 patients were analyzed using data acquired by 64-row CT with a reconstruction thickness of 0.67 mm and an increment of 0.33 mm. TCFA was defined by OCT as a plaque with lipid content in ≥2 quadrants and the thinnest part of the fibrous cap measuring ≤65 μm. The following parameters were obtained from CT: remodeling index (RI), proportion ...

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    18. Spectral Domain Optical Coherence Tomography Angiography in Stargardt's Macular Dystrophy

      Spectral Domain Optical Coherence Tomography Angiography in Stargardt's Macular Dystrophy

      Stargardt's macular dystrophy (SMD) is the most common form of hereditary recessive macular dystrophy, seen in approximately 1 in 10 000 people, and accounts for 7% of all retinal degenerations. 1 The pathophysiology is a well-described mutation in the ABCA4 gene, resulting in the accumulation of lipofuscin (modified residues of incompletely digested photoreceptor outer segments), retinal pigment epithelium (RPE) cell death, and irreversible progressive atrophy in the macula. 2 Optical coherence tomography angiography (OCTA) is a unique imaging technique that provides high-resolution imaging of capillary networks and allows for segmentation of different layers of retinal and choroidal vasculature. 3 ...

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    19. Involuntary Eye Motion Correction in Retinal Optical Coherence Tomography: Hardware or Software Solution?

      Involuntary Eye Motion Correction in Retinal Optical Coherence Tomography: Hardware or Software Solution?

      In this paper, we review state-of-the-art techniques to correct eye motion artifacts in Optical Coherence Tomography (OCT) imaging. The methods for eye motion artifact reduction can be categorized into two major classes: 1) hardware-based techniques and 2) software-based techniques. In the first class, additional hardware is mounted onto the OCT scanner to gather information about the eye motion patterns during OCT data acquisition. This information is later processed and applied to the OCT data for creating an anatomically correct representation of the retina, either in an offline or online manner. In software based techniques, the motion patterns are approximated either ...

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