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    1. Retinal imaging with optical coherence tomography and low‐loss adaptive optics using a 2.8‐mm beam size

      Retinal imaging with optical coherence tomography and low‐loss adaptive optics using a 2.8‐mm beam size

      As data acquisition for retinal imaging with optical coherence tomography (OCT) becomes faster, efficient collection of photons becomes more important to maintain image quality. One approach is to use a larger aperture at the eye’s pupil to collect more photons that have been reflected from the retina. A 2.8‐mm beam diameter system with only 7 reflecting surfaces was developed for low‐loss retinal imaging. The larger beam size requires defocus and astigmatism correction, which was done in a closed loop adaptive optics method using a Shack‐Hartmann wavefront sensor and a deformable mirror with 140 actuators and ...

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    2. Automated assessment of breast cancer margin in optical coherence tomography images via pre‐trained convolutional neural network

      Automated assessment of breast cancer margin in optical coherence tomography images via pre‐trained convolutional neural network

      The benchmark method for the evaluation of breast cancers involves microscopic testing of a hematoxylin and eosin (H&E) stained tissue biopsy. Resurgery is required in 20‐30% of cases because of incomplete excision of malignant tissues. Therefore, a more accurate method is required to detect the cancer margin to avoid the risk of recurrence. In the recent years, convolutional neural networks (CNNs) has achieved excellent performance in the field of medical images diagnosis. It automatically extracts the features from the images and classifies them. In the proposed study, we apply a pre‐trained Inception‐v3 CNN with reverse active ...

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      Mentions: UCLA
    3. Dexamethasone for unresponsive diabetic macular oedema: optical coherence tomography biomarkers

      Dexamethasone for unresponsive diabetic macular oedema: optical coherence tomography biomarkers

      Purpose To analyse the effects of intravitreal dexamethasone implant (DEX) in patients with diabetic macular oedema (DME) unresponsive to ranibizumab treatment, in relation to the inflammatory optical coherence tomography (OCT) retinal features, subfoveal neuroretinal detachment (SND) and hyperreflective retinal spots (HRS). Methods Patients with DME poorly responsive to three injections of ranibizumab were treated with DEX. Best‐corrected visual acuity (BCVA) and central macula thickness (CMT, measured by Spectralis SD‐OCT) were assessed at baseline and at 1, 3, and 6 months. Results Overall, 44 eyes were included in the study. In the whole group, mean BCVA (baseline 51.5 ...

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    4. Super‐achromatic Optical Coherence Tomography Capsule for Ultrahigh‐resolution Imaging of Esophagus

      Super‐achromatic Optical Coherence Tomography Capsule for Ultrahigh‐resolution Imaging of Esophagus

      Endoscopic optical coherence tomography (OCT) is a noninvasive technology allowing for imaging of tissue microanatomies of luminal organs in real time. Conventional endoscopic OCT operates at 1,300 nm wavelength region with a sub‐optimal axial resolution limited to 8‐20 μm. In this paper we present the first ultrahigh‐resolution tethered OCT capsule operating at 800 nm and offering about 3‐4 fold improvement of axial resolution (plus enhanced imaging contrast). The capsule uses diffractive optics to manage chromatic aberration over a full ~200 nm spectral bandwidth centering around 830 nm, enabling to achieve super‐achromaticity and an axial ...

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    5. Evaluation of tear meniscus by optical coherence tomography after different sodium hyaluronate eyedrops instillation

      Evaluation of tear meniscus by optical coherence tomography after different sodium hyaluronate eyedrops instillation

      Purpose To evaluate changes in tear meniscus dynamics using optical coherence tomography (OCT) after the instillation of different concentrations of sodium hyaluronate (SH) ophthalmic solutions. Methods An experimental, double‐masked, randomized study was performed. Twenty‐three healthy subjects (16 women and seven men; mean age 23.57 ± 2.56 years) participated in this study. About 35 μ l of 0.1%, 0.2%, 0.3% SH ophthalmic solutions and saline solution was instilled in a randomly assigned eye. Tear meniscus measurements (height, depth and turbidity) were taken with OCT at 30 seconds and 1, 3, 5, 10 and 20 min after ...

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    6. Predicting the outcome of laser peripheral iridotomy for primary angle closure suspect eyes using anterior segment optical coherence tomography

      Predicting the outcome of laser peripheral iridotomy for primary angle closure suspect eyes using anterior segment optical coherence tomography

      Purpose Develop an algorithm to predict the success of laser peripheral iridotomy (LPI) in primary angle closure suspect (PACS), using pretreatment anterior segment optical coherence tomography (ASOCT) scans. Methods A total of 69 eyes with PACS underwent LPI and time‐domain ASOCT scans (temporal and nasal cuts) were performed before and after LPI. After LPI, success is defined as one or more angles changed from closed to open. All the pretreatment ASOCT scans were analysed using the Anterior Segment Analysis Program to derive anterior chamber angle (ACA) measurements. The measurements for each angle were ordered along with angle‐independent measurements ...

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    7. In vivo microscopic and optical coherence tomography classification of neurotrophic keratopathy

      In vivo microscopic and optical coherence tomography classification of neurotrophic keratopathy

      Neurotrophic keratopathy (NK) is a rare degenerative corneal disorder characterized by instability of epithelial integrity with consequent epithelial defects that can worsen up to persistent epithelial defects with stromal melting and ulceration. The pathogenesis of NK springs from a variable degree of damage to the trigeminal nerve plexus, leading to a reduction or total loss of corneal sensitivity. Mackie classification (1995) distinguishes three stages of NK, based on the severity of clinical presentation. The technological innovations in corneal diagnostic imaging allow clinicians to accurately study the morphometry and morphology of corneal structure with microscopic resolution. In this study, 45 patients ...

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    8. Optical coherence tomography and magnetic resonance imaging visual pathway evaluation in Wolfram syndrome

      Optical coherence tomography and magnetic resonance imaging visual pathway evaluation in Wolfram syndrome

      Aim The aim of this study was to assess parameters of retinal morphology by using high‐definition optical coherence tomography (OCT) in patients with Wolfram syndrome (WFS) and their relation to optic tract atrophy in magnetic resonance imaging (MRI). Method High‐definition OCT and MRI parameters were evaluated in 12 patients with WFS (three males, nine females; median age at examination 12y 8mo, range 10y 2mo–15y 11mo) and referred to 30 individuals with type 1 diabetes (T1D) (12 males, 18 females; median age at examination 20y 5mo, range 16y 8mo–21y 4mo) and 33 typically developing comparison participants (10 ...

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    9. Anterior segment optical coherence tomography: its application in clinical practice and experimental models of disease

      Anterior segment optical coherence tomography: its application in clinical practice and experimental models of disease

      Optical coherence tomography (OCT) provides non‐invasive, high‐resolution in vivo imaging of the ocular surface and anterior segment. Over the years, it has become an essential tool for evaluating the anterior segment of the eye to monitor ocular development and ocular pathologies in both the clinical and research fields of ophthalmology and optometry. In this review, the clinical applications relating to the use of anterior segment OCT for imaging and quantifying normal and pathological features of the ocular surface, cornea, anterior chamber, and aqueous outflow system are summarised in a range of human ocular diseases. Applications of anterior segment ...

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    10. Optical coherence tomography follow‐up of patients treated from periodontal disease

      Optical coherence tomography follow‐up of patients treated from periodontal disease

      Optical coherence tomography (OCT) is one of the most important imaging modalities for biophotonics applications. In this work, an important step towards the clinical use of OCT in dental practice is reported, by following‐up patients treated from periodontal disease (PD). 147 vestibular dental sites from 14 patients diagnosed with PD were evaluated prior and after treatment, using a swept‐source OCT and two periodontal probes (Florida probe and North Carolina) for comparison. The evaluation was performed at four stages: day 0, day 30, day 60 and day 90. Exceptionally one patient was evaluated 1‐year after treatment. It was ...

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    11. Correlation between pre‐procedural plaque morphology and patterns of in‐stent neointimal hyperplasia at 1‐year follow‐up in patients treated with new‐generation drug‐eluting stents: An optical coherence tomography based analysis

      Instruction Several factors affect the in‐stent intimal healing process after drug‐eluting stents (DESs) implantation. We hope to investigate the influence of plaque characteristics on subsequent heterogeneous neointimal hyperplasia (NIH) using optical coherence tomography (OCT). Methods The study population consisted 217 patients with single‐vessel de novo lesions who underwent both pre‐procedural OCT scan and 12‐month follow‐up OCT examination. NIH is defined as at least five consecutive cross‐sectional images with no less than 100µm neointimal thickness. According to OCT follow‐up, patients were divided into three groups: neointima‐covered group, homogeneous, and heterogeneous NIH ...

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    12. Early restenosis of resorbable magnesium scaffolds: Optical coherence tomography findings

      Early restenosis of resorbable magnesium scaffolds: Optical coherence tomography findings

      Resorbable Magnesium Scaffolds (RMS) represent an interesting alternative to current drug‐eluting stents. Current data from clinical trials seems to confirm good performance of these new devices with low rates of late device failure. Little is known about mechanisms leading to RMS failure. Herein, we present the first description of an early RMS in‐scaffold restenosis. Optical coherence tomography (OCT) analysis at implantation detected acute non‐severe malapposition and underexpansion as main promoters of RMS failure. OCT during in‐scaffold restenosis intervention confirmed early severe neointimal proliferation and RMS late recoil and dismantling as the main mechanisms of device failure ...

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      Mentions: Fernando Alfonso
    13. Intraoperative imaging of surgical margins of canine soft tissue sarcoma using optical coherence tomography

      Intraoperative imaging of surgical margins of canine soft tissue sarcoma using optical coherence tomography

      Optical coherence tomography (OCT) is a rapid non‐invasive imaging technique that has shown high sensitivity for intraoperative surgical margin assessment in human breast cancer clinical trials. This promising technology has not been evaluated in veterinary medicine. The objective of this study was to correlate normal and abnormal histological features with OCT images for surgical margins from excised canine soft tissue sarcoma (STS) and to establish image evaluation criteria for identifying positive surgical margins. Fourteen client‐owned dogs underwent surgical resection of a STS and OCT imaging of 2‐4 areas of interest on the resected specimen were performed. Following ...

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    14. The European Eye Epidemiology spectral‐domain optical coherence tomography classification of macular diseases for epidemiological studies

      The European Eye Epidemiology spectral‐domain optical coherence tomography classification of macular diseases for epidemiological studies

      The E3 consortium thanks Cécile Delcourt, Jean‐François Korobelnik, Marie‐Bénédicte Rougier and Marie‐Noëlle Delyfer for organizing the meetings in Bordeaux in 2011, 2012 and 2013, Stefano Piermarocchi for organizing the meeting in Rome in 2014, Chris Hammond, Paul Foster and Tunde Peto for organizing the meeting in London in 2015. These workshops have received financial support from Carl Zeiss Meditec AG, Laboratoires Théa, Novartis and OOgroup. The sponsors had no role in the design or conduct of this research.Pr. Schmitz‐Valckenberg reports grants and personal fees from Allergan, Bayer, Genentech/Roche ...

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    15. Optic nerve head morphology in primary open‐angle glaucoma and nonarteritic anterior ischaemic optic neuropathy measured with spectral domain optical coherence tomography

      Optic nerve head morphology in primary open‐angle glaucoma and nonarteritic anterior ischaemic optic neuropathy measured with spectral domain optical coherence tomography

      Purpose Optic nerve head (ONH) parameters as well as circumpapillary retinal nerve fibre layer (RNFL) thickness values measured with two different spectral domain optical coherence tomography (SD‐OCT) machines (Spectralis ® and Cirrus ® OCT) have been compared between two patient groups, primary open‐angle glaucoma (POAG), nonarteritic anterior ischaemic optic neuropathy (NAION) and healthy controls. A comparison of the performance of the two OCT machines was made. Methods Twenty healthy controls, 20 POAG and 20 NAION patients with comparable visual field defects were included. Comparison between groups was made using anova and post hoc t ‐tests. To evaluate the diagnostic power ...

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    16. Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air‐puff optical coherence tomography and corneal hysteresis

      Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air‐puff optical coherence tomography and corneal hysteresis

      Application of the air‐puff swept source OCT (SS‐OCT) instrument to determine the influence of viscoelasticity on the relation between overall the air‐puff force and corneal apex displacement of porcine corneas ex vivo is demonstrated. Simultaneous recording of time‐evolution of the tissue displacement and air pulse stimulus allows obtaining valuable information related in part to the mechanical properties of the cornea. A novel approach based on quantitative analysis of the corneal hysteresis of OCT data is presented. The corneal response to the air pulse is assessed for different well‐controlled IOP levels and for the progression of ...

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    17. The vascular morphology of melanoma is related to Breslow index: an in vivo study with dynamic optical coherence tomography

      The vascular morphology of melanoma is related to Breslow index: an in vivo study with dynamic optical coherence tomography

      Background Malignant melanoma is an aggressive skin cancer, which can lead to metastasis development. Vascularization enhancement is fundamental for tumor growth, worsening the prognosis. Dynamic Optical Coherence Tomography (D‐OCT) enables the in vivo evaluation of vascular patterns in skin lesions. Objective In vivo evaluation of the melanoma vessel morphology by means of D‐OCT and correlation with Breslow index. Methods Retrospective analysis of histologically proven melanomas, evaluated by D‐OCT at three different depths (150, 300 and 500 μm) was performed. Vessels were classified according to morphology (dots, blobs, coiled, line, curved, serpiginous), distribution (regular, irregular), and presence/type ...

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    18. Schlemm's canal measured by optical coherence tomography and correlation study in a healthy Caucasian child population

      Schlemm's canal measured by optical coherence tomography and correlation study in a healthy Caucasian child population

      Purpose To measure the Schlemm's canal (SC) in vivo by Fourier‐domain optical coherence tomography (FD‐OCT) in a Caucasian paediatric population. Methods Participants of this cross‐sectional study were 290 healthy children. In the right eye of each child, SC cross‐sectional diameter and area measurements were made with the FD‐OCT instrument RTVue ® (Optovue Inc, Fremont, CA, USA) in the nasal and temporal quadrants. These SC variables were then assessed for correlation with the factors age, gender, refractive error, anterior chamber angle and trabecular meshwork (TM) metrics. Finally, the reproducibility of the SC measurements was assessed in ...

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      Mentions: Optovue
    19. Optical coherence tomography angiography and microvascular changes in diabetic retinopathy: a systematic review

      Optical coherence tomography angiography and microvascular changes in diabetic retinopathy: a systematic review

      To use optical coherence tomography angiography (OCTA) to evaluate foveal microvascular changes in diabetes by comparing the area of foveal avascular zone (FAZ) in healthy controls and patients with diabetes with no diabetic retinopathy (NDR) as well as different stages of diabetic retinopathy (DR). A systematic literature search was performed based on the population, intervention, comparison and outcome (PICO) strategy by two independent reviewers. The search was performed in PubMed, Embase and Cochrane Library, including keywords ‘diabetes mellitus’, ‘DR’ and ‘OCTA’. Of 358 studies initially identified, 215 studies were screened after duplicate removal. Of these, we included 12 (nine cross ...

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    20. The utility of optical coherence tomography for diagnosis of basal cell carcinoma: A quantitative review

      The utility of optical coherence tomography for diagnosis of basal cell carcinoma: A quantitative review

      Background Optical coherence tomography (OCT) is a non‐invasive near‐infrared light imaging technology that can be utilized to diagnose basal cell carcinomas (BCCs) based on specific morphologic features. Objectives To conduct a quantitative review using tumor level data from published studies to assess i) in‐vivo diagnostic accuracy of different OCT systems; ii) correlation between OCT features and histopathological diagnosis; and iii) factors that impact accuracy of tumor depth estimation. Methods Primary tumor‐level data were extracted from published studies on use of time‐domain (TD‐OCT), frequency‐domain (FD‐OCT) or high‐definition (HD‐OCT) systems for diagnosis ...

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    1-24 of 890 1 2 3 4 ... 35 36 37 »
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