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    1. Diagnostic Concordance between Optical Coherence Tomography and Histological Investigations for Immune-Mediated Desquamative Gingivitis: Observational Study

      Diagnostic Concordance between Optical Coherence Tomography and Histological Investigations for Immune-Mediated Desquamative Gingivitis: Observational Study

      Desquamative gingivitis (DG) denotes a heterogeneous immune-mediated disease for which early diagnosis represents a great challenge. The main aim of this study is to validate diagnostic concordance between specific Optical Coherence Tomography (OTC) patterns for DG related to oral Lichen Planus (OLP), Pemphigus Vulgaris (PV), and Mucous Membrane Pemphigoid (MMP) and definitive histological diagnosis. Forty-three patients with suspected immune-mediated DGs, were progressively recruited. Before biopsy, an OCT preliminary evaluation was performed using specific pre-determined OCT diagnostic patterns (i.e., morphology and localization of blisters, status of the basal membrane, epithelial thickness, presence/absence of acantholytic cells into blister and/or ...

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    2. In Situ Detection of Interfacial Flow Instabilities in Polymer Co-Extrusion Using Optical Coherence Tomography and Ultrasonic Techniques

      In Situ Detection of Interfacial Flow Instabilities in Polymer Co-Extrusion Using Optical Coherence Tomography and Ultrasonic Techniques

      Co-extrusion is a widely used processing technique for combining various polymers with different properties into a tailored multilayer product. Individual melt streams are combined in a die to form the desired shape. Under certain conditions, interfacial flow instabilities are observed; however, fundamental knowledge about their onset and about critical conditions in science and industry is scarce. Since reliable identification of interfacial co-extrusion flow instabilities is essential for successful operation, this work presents in situ measurement approaches using a novel co-extrusion demonstrator die, which is fed by two separate melt streams that form a well-controlled two-layer co-extrusion polymer melt flow. An ...

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    3. Counterclockwise Drilling with Different Tapered Drills Condenses the Implant Bed—An Optical Coherence Tomography In Vitro Study

      Counterclockwise Drilling with Different Tapered Drills Condenses the Implant Bed—An Optical Coherence Tomography In Vitro Study

      Background and Objectives: To evaluate the condensation and the microarchitecture of implant bed walls of sites prepared with counterclockwise drilling with tapered implant drills using optical coherence tomography. Materials and Methods : Four drill designs with different wall and tip angles were used. Polyurethane laminas resembling type IV bone microarchitecture were superimposed and clamped with a vice to simulate the coronal, middle, and apical aspects of the implant site. Twenty implant beds were prepared at 1200 rpm in clockwise (control) and counterclockwise (test) directions (N = 160). Optical coherence tomography (OCT) was used to evaluate the condensation and microarchitecture characteristics of the ...

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    4. Retinal Vessel Density Changes on Optical Coherence Tomography Angiography and Predictive Factors in Normal-Tension Glaucoma Treated with Topical Beta-Blocker

      Retinal Vessel Density Changes on Optical Coherence Tomography Angiography and Predictive Factors in Normal-Tension Glaucoma Treated with Topical Beta-Blocker

      (1) Background: Topical antiglaucoma medications may alter the microcirculation in the optic nerve head. We aimed to evaluate the changes in retinal vessel density (VD) on optical coherence tomography angiography (OCTA) in patients with newly diagnosed normal-tension glaucoma (NTG) treated with a topical beta-blocker. (2) Methods: This study included 80 patients diagnosed with NTG not using systemic medication, who received topical carteolol treatment between December 2019 and November 2020. We studied the changes in the OCTA VD/signal strength index (SSI) after the 6-month treatment period and determined the predictive factors affecting the changes in VD/SSI. (3) Results: After ...

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    5. Methods of Non-Invasive In Vivo Optical Diagnostics in the Assessment of Structural Changes in the Skin Induced by Ultraviolet Exposure in an Experimental Model

      Methods of Non-Invasive In Vivo Optical Diagnostics in the Assessment of Structural Changes in the Skin Induced by Ultraviolet Exposure in an Experimental Model

      Background: This paper demonstrates the use of optical diagnostic methods to assess the dynamic skin changes observed in acute and chronic exposure to ultraviolet (UV) radiation in vivo. Methods: Firstly, in order to initiate photoaging (chronic UV exposure), animals ( n = 40) were divided into two groups: chronic UV exposure ( n = 30), and control ( n = 10; without irradiation). Photoaging in animals was induced by chronic repeated exposure to UVA radiation three times per week, for 12 weeks continuously, while the UV dose increased stepwise over the course of the experiment (55 minimal erythema doses (MED) in total). Laser fluorescence spectroscopy (LFS ...

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    6. An Automated CAD System for Accurate Grading of Uveitis Using Optical Coherence Tomography Images

      An Automated CAD System for Accurate Grading of Uveitis Using Optical Coherence Tomography Images

      Uveitis is one of the leading causes of severe vision loss that can lead to blindness worldwide. Clinical records show that early and accurate detection of vitreous inflammation can potentially reduce the blindness rate. In this paper, a novel framework is proposed for automatic quantification of the vitreous on optical coherence tomography (OCT) with particular application for use in the grading of vitreous inflammation. The proposed pipeline consists of two stages, vitreous region segmentation followed by a neural network classifier. In the first stage, the vitreous region is automatically segmented using a U-net convolutional neural network (U-CNN). For the input ...

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    7. Disease Progression in CNGA3 and CNGB3 Retinopathy; Characteristics of Slovenian Cohort and Proposed OCT Staging Based on Pooled Data from 126 Patients from 7 Studies

      Disease Progression in CNGA3 and CNGB3 Retinopathy; Characteristics of Slovenian Cohort and Proposed OCT Staging Based on Pooled Data from 126 Patients from 7 Studies

      Achromatopsia has been proposed to be a morphologically predominately stable retinopathy with rare reports of progression of structural changes in the macula. A five-grade system of optical coherence tomography (OCT) features has been used for the classification of structural macular changes. However, their association with age remains questionable. We characterized the Slovenian cohort of 12 patients with pathogenic variants in CNGA3 or CNGB3 who had been followed up with OCT for up to 9 years. Based on observed structural changes in association with age, the following four-stage classification of retinal morphological changes was proposed: (I) preserved inner segment ellipsoid band ...

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    8. Unveiling the Invisible in Uffizi Gallery’s Drawing 8P by Leonardo with Non-Invasive Optical Techniques

      Unveiling the Invisible in Uffizi Gallery’s Drawing 8P by Leonardo with Non-Invasive Optical Techniques

      Until recently, the study of drawings by old masters has been confined to the art history conservation field. More specifically, scientific investigations of Leonardo’s drawings are still very few, possibly due to the latter’s extreme fragility and artistic value. However, analytical data are crucial to develop a solid knowledge base of the drawing materials and techniques used by artists in the past. In this work, we report on the application of non-invasive optical techniques on a double-sided drawing by Leonardo belonging to the Uffizi Gallery (8P). We used multispectral reflectography in the visible (Vis) and near-infrared (NIR) regions ...

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    9. Current Developments in Corneal Topography and Tomography

      Current Developments in Corneal Topography and Tomography

      Introduction: Accurate assessment of the corneal shape is important in cataract and refractive surgery, both in screening of candidates as well as for analyzing postoperative outcomes. Although corneal topography and tomography are widely used, it is common that these technologies are confused. The aim of this study was to present the current developments of these technologies and particularly distinguish between corneal topography and tomography. Methods: The PubMed, Web of Science and Embase databases were the main resources used to investigate the medical literature. The following keywords were used in various combinations: cornea, corneal, topography, tomography, Scheimpflug, Pentacam, optical coherence tomography ...

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    10. Computer-Aided Detection (CADe) System with Optical Coherent Tomography for Melanin Morphology Quantification in Melasma Patients

      Computer-Aided Detection (CADe) System with Optical Coherent Tomography for Melanin Morphology Quantification in Melasma Patients

      Dark skin-type individuals have a greater tendency to have pigmentary disorders, among which melasma is especially refractory to treat and often recurs. Objective measurement of melanin amount helps evaluate the treatment response of pigmentary disorders. However, naked-eye evaluation is subjective to weariness and bias. We used a cellular resolution full-field optical coherence tomography (FF-OCT) to assess melanin features of melasma lesions and perilesional skin on the cheeks of eight Asian patients. A computer-aided detection (CADe) system is proposed to mark and quantify melanin. This system combines spatial compounding-based denoising convolutional neural networks (SC-DnCNN), and through image processing techniques, various types ...

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    11. Stability of OCT and OCTA in the Intensive Therapy Unit Setting

      Stability of OCT and OCTA in the Intensive Therapy Unit Setting

      To assess the stability of retinal structure and blood flow measures over time and in different clinical settings using portable optical coherence tomography angiography (OCTA) as a potential biomarker of central perfusion in critical illness, 18 oesophagectomy patients completed retinal structure and blood flow measurements by portable OCT and OCTA in the eye clinic and intensive therapy unit (ITU) across three timepoints: (1) pre-operation in a clinic setting; (2) 24-48 h post-operation during ITU admission; and (3) seven days post-operation, if the patient was still admitted. Blood flow and macular structural measures were stable between the examination settings, with no ...

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    12. Automatic Diagnosis of Bipolar Disorder Using Optical Coherence Tomography Data and Artificial Intelligence

      Automatic Diagnosis of Bipolar Disorder Using Optical Coherence Tomography Data and Artificial Intelligence

      Background: The aim of this study is to explore an objective approach that aids the diagnosis of bipolar disorder (BD), based on optical coherence tomography (OCT) data which are analyzed using artificial intelligence. Methods: Structural analyses of nine layers of the retina were analyzed in 17 type I BD patients and 42 controls, according to the areas defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The most discriminating variables made up the feature vector of several automatic classifiers: Gaussian Naive Bayes, K-nearest neighbors and support vector machines. Results: BD patients presented retinal thinning affecting most layers, compared to ...

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    13. Insights into the Development of Phototrophic Biofilms in a Bioreactor by a Combination of X-ray Microtomography and Optical Coherence Tomography

      Insights into the Development of Phototrophic Biofilms in a Bioreactor by a Combination of X-ray Microtomography and Optical Coherence Tomography

      As productive biofilms are increasingly gaining interest in research, the quantitative monitoring of biofilm formation on- or offline for the process remains a challenge. Optical coherence tomography (OCT) is a fast and often used method for scanning biofilms, but it has difficulty scanning through more dense optical materials. X-ray microtomography (μCT) can measure biofilms in most geometries but is very time-consuming. By combining both methods for the first time, the weaknesses of both methods could be compensated. The phototrophic cyanobacterium Tolypothrix distorta was cultured in a moving bed photobioreactor inside a biocarrier with a semi-enclosed geometry. An automated workflow was ...

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    14. Optical Coherence Tomography Angiography in Type 1 Diabetes Mellitus. Report 4: Glycated Haemoglobin

      Optical Coherence Tomography Angiography in Type 1 Diabetes Mellitus. Report 4: Glycated Haemoglobin

      The purpose of this study was to evaluate specifically the relationship between glycated haemoglobin (HbA1c) levels and retinal optical coherence tomography (OCT) and OCT angiography (OCTA) parameters in type 1 Diabetes Mellitus (DM). A total of 478 type 1 DM patients and 115 controls were included in a prospective OCTA trial (ClinicalTrials.gov NCT03422965). Subgroup analysis was performed for controls, no diabetic retinopathy (DM-no DR) and DR patients (DM-DR), and HbA1c levels. OCT and OCTA measurements were compared with HbA1c levels (current and previous 5 years). DM-no DR patients with HbA1c levels >7.5% showed lower VD than DM-DR and ...

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    15. Quantitative Trait Locus Analysis of Microscopic Phenotypic Characteristic Data Obtained Using Optical Coherence Tomography Imaging of Rice Bacterial Leaf Blight Infection in the Field

      Quantitative Trait Locus Analysis of Microscopic Phenotypic Characteristic Data Obtained Using Optical Coherence Tomography Imaging of Rice Bacterial Leaf Blight Infection in the Field

      Rapid climate change has increased the incidence of various pests and diseases, and these threaten global food security. In particular, BLB (bacterial leaf blight) is caused by Xoo ( Xanthomonas oryzae pv. oryzae ) and its main characteristic is that the rice suddenly dries and withers. Recently, omics have been effectively used in agriculture. In particular, it is a key technology that can accurately diagnose diseases in the field. Until now, QTL (quantitative trait loci) mapping has been analyzed using only subjective phenotypic data by experts. However, in this study, diseases were accurately diagnosed using OCT (optical coherence tomography), and QTL mapping ...

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    16. Immune-Mediated Desquamative Gingivitis and Optical Coherence Tomography Diagnostic Patterns: Clinical Implication from a Systematic Review

      Immune-Mediated Desquamative Gingivitis and Optical Coherence Tomography Diagnostic Patterns: Clinical Implication from a Systematic Review

      Desquamative Gingivitis (DG) comprises heterogeneous clinical manifestations of numerous immune-mediated muco-cutaneous diseases. Optical Coherence Tomography (OCT) has been proposed as a valuable diagnostic support even if, to date, there are no standardized OCT-diagnostic patterns applicable to DGs. A systematic review was performed to detect existing data on in vivo OCT diagnostic patterns of the most common immune-mediated DGs (i.e., pemphigus vulgaris, mucous membrane pemphigoid and oral lichen planus). It has been found that OCT exhibits specific patterns that address the diagnosis of DG by pemphigus vulgaris (i.e., intraepithelial unilocular blister, reduced epithelial thickness, presence of acantholytic cells in ...

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    17. Automatic Quantification of Anterior Lamina Cribrosa Structures in Optical Coherence Tomography Using a Two-Stage CNN Framework

      Automatic Quantification of Anterior Lamina Cribrosa Structures in Optical Coherence Tomography Using a Two-Stage CNN Framework

      In this study, we propose a new intelligent system to automatically quantify the morphological parameters of the lamina cribrosa (LC) of the optical coherence tomography (OCT), including depth, curve depth, and curve index from OCT images. The proposed system consisted of a two-stage deep learning (DL) model, which was composed of the detection and the segmentation models as well as a quantification process with a post-processing scheme. The models were used to solve the class imbalance problem and obtain Bruch’s membrane opening (BMO) as well as anterior LC information. The detection model was implemented by using YOLOv3 to acquire ...

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    18. Retinal OCT Findings in Patients after COVID Infection

      Retinal OCT Findings in Patients after COVID Infection

      Purpose: The aim of this study was to assess and compare the optic nerve, retina, and retinal vessel parameters in recovered COVID-19 patients and healthy patients by using optical coherence tomography angiography (OCT-a). Methods: In all, 156 eyes of post-COVID-19 patients and 98 eyes of subjects from a control group were enrolled in our study. BCVA, intra ocular pressure (IOP) measurement, fundus examination, and OCT images, including macular cube, OCT-RNFL, and angio-OCT 6 × 6 mm examinations, were performed for both groups. The measurements were acquired using Swept Source OCT DRI OCT Triton. In the post-COVID-19 group, 762 OCT protocols were ...

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    19. Interobserver and Intertest Agreement in Telemedicine Glaucoma Screening with Optic Disk Photos and Optical Coherence Tomography

      Interobserver and Intertest Agreement in Telemedicine Glaucoma Screening with Optic Disk Photos and Optical Coherence Tomography

      Purpose : To evaluate interobserver and intertest agreement between optical coherence tomography (OCT) and retinography in the detection of glaucoma through a telemedicine program. Methods : A stratified sample of 4113 individuals was randomly selected, and those who accepted underwent examination including visual acuity, intraocular pressure (IOP), non-mydriatic retinography, and imaging using a portable OCT device. Participants' data and images were uploaded and assessed by 16 ophthalmologists on a deferred basis. Two independent evaluations were performed for all participants. Agreement between methods was assessed using the kappa coefficient and the prevalence-adjusted bias-adjusted kappa (PABAK). We analyzed potential factors possibly influencing the level ...

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    20. Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

      Non-Destructive Subsurface Inspection of Marine and Protective Coatings Using Near- and Mid-Infrared Optical Coherence Tomography

      Near- and mid-infrared optical coherence tomography (OCT) is evaluated as a non-destructive and non-contact reflection imaging modality for inspection of industrial and marine coatings. Near-infrared OCT was used to obtain high-resolution images (~6/2 µm lateral/axial) of hidden subsurface cracks and defects in a resin base coating, which had been exposed to high pressure and high temperature to study coating degradation in hostile environments. Mid-infrared OCT was employed for high-resolution (~15/8.5 µm lateral/axial) subsurface inspection of highly scattering marine coatings, demonstrating monitoring of wet film thickness and particle dispersion during curing of a 210 µm layer ...

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    21. Lesion Geometry as Assessed by Optical Coherence Tomography Is Related to Myocardial Ischemia as Determined by Cardiac Magnetic Resonance Imaging

      Lesion Geometry as Assessed by Optical Coherence Tomography Is Related to Myocardial Ischemia as Determined by Cardiac Magnetic Resonance Imaging

      Introduction: Although the relationship between the geometry of coronary stenosis and the presence of myocardial ischemia is well known, the association between stenosis geometry and severity and/or extent of ischemia is still unexplored. Thus, we investigated this relationship using optical coherence tomography (OCT) to assess stenosis parameters and cardiac magnetic resonance imaging (CMR) to determine both extent and severity of ischemia. Methods: We analyzed 55 lesions from 51 patients with stable angina. Pre-interventionally, all patients underwent OCT-analysis of stenosis morphology as well as CMR to determine both the extent and severity of myocardial ischemia. Results: Percent area stenosis (%AS ...

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    22. Validation of a Point-of-Care Optical Coherence Tomography Device with Machine Learning Algorithm for Detection of Oral Potentially Malignant and Malignant Lesions

      Validation of a Point-of-Care Optical Coherence Tomography Device with Machine Learning Algorithm for Detection of Oral Potentially Malignant and Malignant Lesions

      Non-invasive strategies that can identify oral malignant and dysplastic oral potentially-malignant lesions (OPML) are necessary in cancer screening and long-term surveillance. Optical coherence tomography (OCT) can be a rapid, real time and non-invasive imaging method for frequent patient surveillance. Here, we report the validation of a portable, robust OCT device in 232 patients (lesions: 347) in different clinical settings. The device deployed with algorithm-based automated diagnosis, showed efficacy in delineation of oral benign and normal ( n = 151), OPML ( n = 121), and malignant lesions ( n = 75) in community and tertiary care settings. This study showed that OCT images analyzed by automated ...

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    23. Non-Invasive Optical Coherence Tomography Data-Based Quantitative Algorithm for the Assessment of Residual Adhesive on Bracket-Removed Dental Surface

      Non-Invasive Optical Coherence Tomography Data-Based Quantitative Algorithm for the Assessment of Residual Adhesive on Bracket-Removed Dental Surface

      The aim of this study was to quantitatively assess the residual adhesive on orthodontic ceramic bracket-removed dental surface. In orthodontic process, ceramic bracket was repeated debonding physically, then the adhesive remained on the dental surface. The residual adhesive caused a lack of adhesive strength between dental and ceramic bracket. Since commonly used adhesive in orthodontics is translucent, residual adhesive is hard to be detected with conventional microscopes. Therefore, 1310 nm center wavelength swept-source OCT system based on laboratory customized image processing algorithm was used for the precise detection of residual adhesive on tooth surface. The algorithm separates residual adhesive from ...

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    24. Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

      Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

      The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution ...

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