1. Articles from peter a. calabresi

    1-24 of 50 1 2 »
    1. Optimal intereye difference thresholds by optical coherence tomography in multiple sclerosis: An international study

      Optimal intereye difference thresholds by optical coherence tomography in multiple sclerosis: An international study

      Objective To determine the optimal thresholds for intereye differences in retinal nerve fiber and ganglion cell + inner plexiform layer thicknesses for identifying unilateral optic nerve lesions in multiple sclerosis. Current international diagnostic criteria for multiple sclerosis do not include the optic nerve as a lesion site despite frequent involvement. Optical coherence tomography detects retinal thinning associated with optic nerve lesions. Methods In this multicenter international study at 11 sites, optical coherence tomography was measured for patients and healthy controls as part of the International Multiple Sclerosis Visual System Consortium. High‐ and low‐contrast acuity were also collected in a subset ...

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    2. Optimal Inter‐Eye Difference Thresholds by OCT in MS: An International Study

      Optimal Inter‐Eye Difference Thresholds by OCT in MS: An International Study

      Objective To determine the optimal thresholds for inter‐eye differences in retinal nerve fiber and ganglion cell+inner plexiform layer thicknesses for identifying unilateral optic nerve lesions in multiple sclerosis. Background Current international diagnostic criteria for multiple sclerosis do not include the optic nerve as a lesion site despite frequent involvement. Optical coherence tomography detects retinal thinning associated with optic nerve lesions. Methods In this multi‐center international study at 11 sites, optical coherence tomography was measured for patients and healthy controls as part of the International Multiple Sclerosis Visual System Consortium. High‐ and low‐contrast acuity were also collected ...

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    3. Image Artifacts In Optical Coherence Tomography Angiography Among Patients With Multiple Sclerosis

      Image Artifacts In Optical Coherence Tomography Angiography Among Patients With Multiple Sclerosis

      Purpose : To evaluate artifacts in OCT-A images of multiple sclerosis (MS) patients and healthy controls. Materials and Methods : This was a prospective cross-sectional study conducted at the Department of Neurology and the Wilmer Eye Institute at Johns Hopkins Hospital. Subjects included patients with an established diagnosis of MS and healthy volunteers. OCT-A was performed using Spectralis® OCT-A prototype, OCT2 (Heidelberg, Germany). The type and frequency of artifacts, the clinical factors associated with them, and their impact on vessel density measurements were assessed. Results : Overall, 385 images from 102 participants were analyzed. The majority of images (97.1%) had some degree ...

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    4. Retinal layer parcellation of optical coherence tomography images: Data resource for Multiple Sclerosis and Healthy Controls

      Retinal layer parcellation of optical coherence tomography images: Data resource for Multiple Sclerosis and Healthy Controls

      This paper presents optical coherence tomography (OCT) images of the human retina and manual delineations of eight retinal layers. The data includes 35 human retina scans acquired on a Spectralis OCT system (Heidelberg Engineering, Heidelberg, Germany), 14 of which are healthy controls (HC) and 21 have a diagnosis of multiple sclerosis (MS). The provided data includes manually delineation of eight retina layers, which were independently reviewed and edited. The data presented in this article was used to validate automatic segmentation algorithms [1].

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    5. Spinal cord and infratentorial lesions in radiologically isolated syndrome are associated with decreased retinal ganglion cell/inner plexiform layer thickness

      Spinal cord and infratentorial lesions in radiologically isolated syndrome are associated with decreased retinal ganglion cell/inner plexiform layer thickness

      Background: The role of retinal imaging with optical coherence tomography (OCT) in assessing individuals with radiologically isolated syndrome (RIS) remains largely unexplored. Objective: To assess retinal layer thicknesses in RIS and examine their associations with clinical features suggestive of increased risk for conversion to multiple sclerosis (MS). Methods: A total of 30 RIS subjects and 60 age- and sex-matched healthy controls (HC) underwent retinal imaging with spectral-domain OCT, followed by automated segmentation of retinal layers. Results: Overall, retinal layer thicknesses did not differ between RIS and HC. However, RIS subjects with spinal cord (SC) lesions had lower ganglion cell + inner ...

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    6. The International Multiple Sclerosis Visual System Consortium: Advancing Visual System Research in Multiple Sclerosis

      The International Multiple Sclerosis Visual System Consortium: Advancing Visual System Research in Multiple Sclerosis

      Background: The International Multiple Sclerosis Visual System Consortium (IMSVISUAL) was formed in November 2014 with the primary goal of improving research, care, and education regarding the role of the visual system in multiple sclerosis (MS) and related disorders. Methods: In this review, we describe the formation, goals, activities, and structure of IMSVISUAL, as well as the relationship of IMSVISUAL with the Americas Committee for Treatment and Research in MS (ACTRIMS). Finally, we provide an overview of the work IMSVISUAL has completed to date, as well as an outline of research projects ongoing under the auspices of IMSVISUAL. Results: IMSVISUAL has ...

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    7. Emerging Applications of Optical Coherence Tomography Angiography (OCTA) in neurological research

      Emerging Applications of Optical Coherence Tomography Angiography (OCTA) in neurological research

      Purpose To review the clinical and research value of optical coherence tomography angiography (OCTA) in the field of neurology. Methods Current literature involving OCTA were reviewed through PubMed using the search terms “optical coherence tomography angiography”, with “multiple sclerosis”, “Alzheimer’s disease”, “optic neuropathy”, or other closely-related terms. Results OCTA has been applied in research to advance our understanding of the pathobiology of neurological disorders. OCTA-derived blood flow and vessel density measures are altered in multiple sclerosis (MS), Alzheimer’s disease (AD), and various optic neuropathies (ON) in varying regions of the posterior segment vasculature of the eye. These emerging ...

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    8. Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study

      Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study

      Background Most patients with multiple sclerosis without previous optic neuritis have thinner retinal layers than healthy controls. We assessed the role of peripapillary retinal nerve fibre layer (pRNFL) thickness and macular volume in eyes with no history of optic neuritis as a biomarker of disability worsening in a cohort of patients with multiple sclerosis who had at least one eye without optic neuritis available. Methods In this multicentre, cohort study, we collected data about patients (age ≥16 years old) with clinically isolated syndrome, relapsing-remitting multiple sclerosis, and progressive multiple sclerosis. Patients were recruited from centres in Spain, Italy, France, Germany ...

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    9. Optical coherence tomography: A quantitative tool to measure neurodegeneration and facilitate testing of novel treatments for tissue protection in multiple sclerosis

      Optical coherence tomography: A quantitative tool to measure neurodegeneration and facilitate testing of novel treatments for tissue protection in multiple sclerosis

      Optical coherence tomography (OCT) is a relatively new imaging technology that has been introduced as a powerful biomarker in neurological disease, including multiple sclerosis. In this review, OCT as an imaging technique, its reproducibility and validation in multiple sclerosis, application to other neurodegenerative diseases and future technological directions are discussed.

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    10. Voxel based morphometry in optical coherence tomography: validation and core findings

      Voxel based morphometry in optical coherence tomography: validation and core findings

      Optical coherence tomography (OCT) of the human retina is now becoming established as an important modality for the detection and tracking of various ocular diseases. Voxel based morphometry (VBM) is a long standing neuroimaging analysis technique that allows for the exploration of the regional differences in the brain. There has been limited work done in developing registration based methods for OCT, which has hampered the advancement of VBM analyses in OCT based population studies. Following on from our recent development of an OCT registration method, we explore the potential benefits of VBM analysis in cohorts of healthy controls (HCs) and ...

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    11. Simultaneous segmentation of retinal surfaces and microcystic macular edema in SDOCT volumes

      Simultaneous segmentation of retinal surfaces and microcystic macular edema in SDOCT volumes

      Optical coherence tomography (OCT) is a noninvasive imaging modality that has begun to find widespread use in retinal imaging for the detection of a variety of ocular diseases. In addition to structural changes in the form of altered retinal layer thicknesses, pathological conditions may also cause the formation of edema within the retina. In multiple sclerosis, for instance, the nerve fiber and ganglion cell layers are known to thin. Additionally, the formation of pseudocysts called microcystic macular edema (MME) have also been observed in the eyes of about 5% of MS patients, and its presence has been shown to be ...

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    12. Combined registration and motion correction of longitudinal retinal OCT data

      Combined registration and motion correction of longitudinal retinal OCT data

      Optical coherence tomography (OCT) has become an important modality for examination of the eye. To measure layer thicknesses in the retina, automated segmentation algorithms are often used, producing accurate and reliable measurements. However, subtle changes over time are difficult to detect since the magnitude of the change can be very small. Thus, tracking disease progression over short periods of time is difficult. Additionally, unstable eye position and motion alter the consistency of these measurements, even in healthy eyes. Thus, both registration and motion correction are important for processing longitudinal data of a specific patient. In this work, we propose a ...

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    13. Optical Coherence Tomography in Neurologic Disease (Textbook)

      Optical Coherence Tomography in Neurologic Disease (Textbook)

      Shortly after the invention of the first two-dimensional optical coherence tomography (OCT) scans by James Fujimoto and colleagues at the Massachusetts Institute of Technology in 1991, ophthalmologists recognized the extraordinary potential for OCT to facilitate quantitative assessment of the neuroretina. OCT rapidly became a commonplace tool in ophthalmologic practice to identify both inflammatory and degenerative conditions affecting the optic nerve and retina. The utility of OCT to detect and quantify sequelae of optic neuropathies, including glaucoma and those associated with primary neurological diseases , was soon brought to the forefront. Rapid advances in the technology have followed and have included faster ...

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    14. Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study

      Retinal thickness measured with optical coherence tomography and risk of disability worsening in multiple sclerosis: a cohort study

      Background Most patients with multiple sclerosis without previous optic neuritis have thinner retinal layers than healthy controls. We assessed the role of peripapillary retinal nerve fibre layer (pRNFL) thickness and macular volume in eyes with no history of optic neuritis as a biomarker of disability worsening in a cohort of patients with multiple sclerosis who had at least one eye without optic neuritis available. Methods In this multicentre, cohort study, we collected data about patients (age ≥16 years old) with clinically isolated syndrome, relapsing-remitting multiple sclerosis, and progressive multiple sclerosis. Patients were recruited from centres in Spain, Italy, France, Germany ...

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    15. Optical coherence tomography reflects brain atrophy in multiple sclerosis: A four-year study

      Optical coherence tomography reflects brain atrophy in multiple sclerosis: A four-year study

      Objective The aim of this work was to determine whether atrophy of specific retinal layers and brain substructures are associated over time, in order to further validate the utility of optical coherence tomography (OCT) as an indicator of neuronal tissue damage in patients with multiple sclerosis (MS). Methods Cirrus high-definition OCT (including automated macular segmentation) was performed in 107 MS patients biannually (median follow-up: 46 months). Three-Tesla magnetic resonance imaging brain scans (including brain-substructure volumetrics) were performed annually. Individual-specific rates of change in retinal and brain measures (estimated with linear regression) were correlated, adjusting for age, sex, disease duration, and ...

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    16. Optical coherence tomography reflects brain atrophy in MS: A four year study

      Optical coherence tomography reflects brain atrophy in MS: A four year study

      Objective : To determine whether atrophy of specific retinal layers and brain substructures are associated over time, in order to further validate the utility of optical coherence tomography (OCT) as an indicator of neuronal tissue damage in patients with multiple sclerosis (MS). Methods : Cirrus high definition OCT (including automated macular segmentation) was performed in 107 MS patients biannually (median follow-up: 46-months). Three-tesla magnetic resonance imaging brain scans (including brain-substructure volumetrics) were performed annually. Individual-specific rates of change in retinal and brain measures (estimated with linear regression) were correlated, adjusting for age, sex, disease duration, and optic neuritis (ON) history. Results : Rates ...

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    17. Segmentation of microcystic macular edema in Cirrus OCT scans with an exploratory longitudinal study

      Segmentation of microcystic macular edema in Cirrus OCT scans with an exploratory longitudinal study

      Microcystic macular edema (MME) is a term used to describe pseudocystic spaces in the inner nuclear layer (INL) of the human retina. It has been noted in multiple sclerosis (MS) as well as a variety of other diseases. The processes that lead to MME formation and their change over time have yet to be explained sufficiently. The low rate at which MME occurs within such diverse patient groups makes the identification and consistent quantification of this pathology important for developing patient-specific prognoses. MME is observed in optical coherence tomography (OCT) scans of the retina as changes in light reflectivity in ...

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    18. Applying an Open-Source Segmentation Algorithm to Different OCT Devices in Multiple Sclerosis Patients and Healthy Controls: Implications for Clinical Trials

      Applying an Open-Source Segmentation Algorithm to Different OCT Devices in Multiple Sclerosis Patients and Healthy Controls: Implications for Clinical Trials

      Background . The lack of segmentation algorithms operative across optical coherence tomography (OCT) platforms hinders utility of retinal layer measures in MS trials. Objective . To determine cross-sectional and longitudinal agreement of retinal layer thicknesses derived from an open-source, fully-automated, segmentation algorithm, applied to two spectral-domain OCT devices. Methods . Cirrus HD-OCT and Spectralis OCT macular scans from 68 MS patients and 22 healthy controls were segmented. A longitudinal cohort comprising 51 subjects (mean follow-up: 1.4 ± 0.9 years) was also examined. Bland-Altman analyses and interscanner agreement indices were utilized to assess agreement between scanners. Results . Low mean differences (−2.16 to ...

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    19. Optical Coherence Tomography in Neurologic Diseases (Textbook)

      Optical Coherence Tomography in Neurologic Diseases (Textbook)

      Optical coherence tomography [OCT] provides tissue morphology imagery at much higher resolution than other imaging modalities such as MRI or ultrasound, and the machines are comparatively cheaper. It is an easy technique to perform; is non-ionizing, and therefore safe. These benefits are driving a rapid transformation of OCT, from its principal application as a research tool, into an extension of the 'neurological examination' in routine office practice. Originally used in assessing the severity of tissue damage and prognosis of multiple sclerosis and various neuro-ophthalmic conditions, OCT is increasingly used in other neurological disorders such as Parkinson's disease, ALS, and ...

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    20. Longitudinal graph-based segmentation of macular OCT using fundus alignment

      Longitudinal graph-based segmentation of macular OCT using fundus alignment

      Segmentation of retinal layers in optical coherence tomography (OCT) has become an important diagnostic tool for a variety of ocular and neurological diseases. Currently all OCT segmentation algorithms analyze data independently, ignoring previous scans, which can lead to spurious measurements due to algorithm variability and failure to identify subtle changes in retinal layers. In this paper, we present a graph-based segmentation framework to provide consistent longitudinal segmentation results. Regularization over time is accomplished by adding weighted edges between corresponding voxels at each visit. We align the scans to a common subject space before connecting the graphs by registering the data ...

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    21. Automatic segmentation of microcystic macular edema in OCT

      Automatic segmentation of microcystic macular edema in OCT

      Microcystic macular edema (MME) manifests as small, hyporeflective cystic areas within the retina. For reasons that are still largely unknown, a small proportion of patients with multiple sclerosis (MS) develop MME—predominantly in the inner nuclear layer. These cystoid spaces, denoted pseudocysts, can be imaged using optical coherence tomography (OCT) where they appear as small, discrete, low intensity areas with high contrast to the surrounding tissue. The ability to automatically segment these pseudocysts would enable a more detailed study of MME than has been previously possible. Although larger pseudocysts often appear quite clearly in the OCT images, the multi-frame averaging ...

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    22. Optical coherence tomography should be part of the routine monitoring of patients with multiple sclerosis: Yes

      Optical coherence tomography should be part of the routine monitoring of patients with multiple sclerosis: Yes

      Magnetic resonance imaging (MRI) of the brain is the most widely established imaging modality for monitoring multiple sclerosis (MS). Although conventional MRI parameters such as the development of new T2 lesions and/or contrast-enhancing lesions are sensitive to inflammatory disease activity, the association between MRI markers of inflammation and disability progression in MS is modest. 1 Conversely, MRI measures of neurodegeneration, such as whole-brain atrophy, correlate well with disability progression, 2 with neurodegeneration considered the principal pathological substrate underlying disability in MS. MRI segmentation techniques also enable the measurement of brain substructure volumes. Gray matter (GM) atrophy is now recognized ...

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    23. Analysis of macular OCT images using deformable registration

      Analysis of macular OCT images using deformable registration

      Optical coherence tomography (OCT) of the macula has become increasingly important in the investigation of retinal pathology. However, deformable image registration, which is used for aligning subjects for pairwise comparisons, population averaging, and atlas label transfer, has not been well–developed and demonstrated on OCT images. In this paper, we present a deformable image registration approach designed specifically for macular OCT images. The approach begins with an initial translation to align the fovea of each subject, followed by a linear rescaling to align the top and bottom retinal boundaries. Finally, the layers within the retina are aligned by a deformable ...

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    24. An adaptive grid for graph-based segmentation in retinal OCT

      An adaptive grid for graph-based segmentation in retinal OCT

      Graph-based methods for retinal layer segmentation have proven to be popular due to their efficiency and accuracy. These methods build a graph with nodes at each voxel location and use edges connecting nodes to encode the hard constraints of each layer's thickness and smoothness. In this work, we explore deforming the regular voxel grid to allow adjacent vertices in the graph to more closely follow the natural curvature of the retina. This deformed grid is constructed by fixing node locations based on a regression model of each layer's thickness relative to the overall retina thickness, thus we generate ...

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    1-24 of 50 1 2 »
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