1. Articles from Bianca S. Gerendas

    1-20 of 20
    1. Optical coherence tomography in multiple sclerosis: A 3-year prospective multicenter study

      Optical coherence tomography in multiple sclerosis: A 3-year prospective multicenter study

      Objective: To evaluate changes over 3 years in the thickness of inner retinal layers including the peripapillary retinal nerve fiber layer (pRNFL), and combined macular ganglion cell and inner plexiform layers (mGCIPL), in individuals with relapsing-remitting multiple sclerosis (RRMS) versus healthy controls; to determine whether optical coherence tomography (OCT) is sufficiently sensitive and reproducible to detect small degrees of neuroaxonal loss over time that correlate with changes in brain volume and disability progression as measured by the Expanded Disability Status Scale (EDSS). Methods: Individuals with RRMS from 28 centers (n = 333) were matched with 64 healthy participants. OCT scans were ...

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    2. Optical coherence tomography in multiple sclerosis: A 3-year prospective multicenter study

      Optical coherence tomography in multiple sclerosis: A 3-year prospective multicenter study

      Objective: To evaluate changes over 3 years in the thickness of inner retinal layers including the peripapillary retinal nerve fiber layer (pRNFL), and combined macular ganglion cell and inner plexiform layers (mGCIPL), in individuals with relapsing-remitting multiple sclerosis (RRMS) versus healthy controls; to determine whether optical coherence tomography (OCT) is sufficiently sensitive and reproducible to detect small degrees of neuroaxonal loss over time that correlate with changes in brain volume and disability progression as measured by the Expanded Disability Status Scale (EDSS). Methods: Individuals with RRMS from 28 centers (n = 333) were matched with 64 healthy participants. OCT scans were ...

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    3. Deep Learning–Based Automated Optical Coherence Tomography Segmentation in Clinical Routine: Getting Closer

      Deep Learning–Based Automated Optical Coherence Tomography Segmentation in Clinical Routine: Getting Closer

      Recently, many ophthalmologists have heard the keywords artificial intelligence , machine learning , deep learning , and automatization at every conference and keynote lecture and seen them in every ophthalmology journal. 1 Many studies 1 have evaluated the use of such algorithms on large retrospective data sets—primarily on color fundus photographs at first, then on optical coherence tomography (OCT) images as well. Most of these have been study data sets with standardized and well-structured imaging protocols and reading center image collections with a predefined protocol, and therefore of good quality. However, how functional will algorithms be in a busy clinical routine? Can ...

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    4. The impact of structural optical coherence tomography changes on visual function in retinal vein occlusion

      The impact of structural optical coherence tomography changes on visual function in retinal vein occlusion

      Purpose We aimed to determine the correlation between optical coherence tomography (OCT)‐ and demographic features and baseline best corrected visual acuity (BCVA) in treatment‐naïve patients with retinal vein occlusion (RVO). Methods This was a cross‐sectional posthoc analysis of OCT images that included RVO patients from two prospective, open‐label, multicentre studies. The morphological grading was done manually, in the standardized setting of a reading centre. Main outcome measure was the estimated difference in Early Treatment Diabetic Retinopathy Study letters associated with each individual biomarker. Results Included were 381/301 treatment‐naïve patients with BRVO/CRVO. For ...

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    5. Automated Quantification of Photoreceptor alteration in macular disease using Optical Coherence Tomography and Deep Learning

      Automated Quantification of Photoreceptor alteration in macular disease using Optical Coherence Tomography and Deep Learning

      Diabetic macular edema (DME) and retina vein occlusion (RVO) are macular diseases in which central photoreceptors are affected due to pathological accumulation of fluid. Optical coherence tomography allows to visually assess and evaluate photoreceptor integrity, whose alteration has been observed as an important biomarker of both diseases. However, the manual quantification of this layered structure is challenging, tedious and time-consuming. In this paper we introduce a deep learning approach for automatically segmenting and characterising photoreceptor alteration. The photoreceptor layer is segmented using an ensemble of four different convolutional neural networks. En-face representations of the layer thickness are produced to characterize ...

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    6. An amplified-target loss approach for photoreceptor layer segmentation in pathological OCT scans

      An amplified-target loss approach for photoreceptor layer segmentation in pathological OCT scans

      Segmenting anatomical structures such as the photoreceptor layer in retinal optical coherence tomography (OCT) scans is challenging in pathological scenarios. Supervised deep learning models trained with standard loss functions are usually able to characterize only the most common disease appeareance from a training set, resulting in suboptimal performance and poor generalization when dealing with unseen lesions. In this paper we propose to overcome this limitation by means of an augmented target loss function framework. We introduce a novel amplified-target loss that explicitly penalizes errors within the central area of the input images, based on the observation that most of the ...

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    7. Correlation between morphological characteristics in spectral‐domain‐optical coherence tomography, different functional tests and a patient's subjective handicap in acute central serous chorioretinopathy

      Correlation between morphological characteristics in spectral‐domain‐optical coherence tomography, different functional tests and a patient's subjective handicap in acute central serous chorioretinopathy

      Purpose The purpose of this study was to identify quantitatively measurable morphologic optical coherence tomography (OCT) characteristics in patients with an acute episode of central serous chorioretinopathy (CSC) and evaluate their correlation to functional and psychological variables for their use in daily clinical practice. Methods Retinal thickness (RT), the height, area and volume of subretinal fluid (SRF)/pigment epithelium detachments were evaluated using the standardized procedures of the Vienna Reading Center. These morphologic characteristics were compared with functional variables [best‐corrected visual acuity (BCVA), contrast sensitivity (CS), retinal sensitivity/microperimetry, fixation stability], and patients’ subjective handicap from CSC using the ...

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    8. Predicting Macular Edema Recurrence from Spatio-Temporal Signatures in Optical Coherence Tomography Images

      Predicting Macular Edema Recurrence from Spatio-Temporal Signatures in Optical Coherence Tomography Images

      Prediction of treatment responses from available data is key to optimizing personalized treatment. Retinal diseases are treated over long periods and patients’ response patterns differ substantially, ranging from a complete response to a recurrence of the disease and need for re-treatment at different intervals. Linking observable variables in high-dimensional observations to outcome is challenging. In this paper, we present and evaluate two different data-driven machine learning approaches operating in a high-dimensional feature space: sparse logistic regression and random forests-based extra trees (ET). Both identify spatio-temporal signatures based on retinal thickness features measured in longitudinal spectral-domain optical coherence tomography (OCT) imaging ...

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    9. Predicting Macular Edema Recurrence from Spatio-Temporal Signatures in Optical Coherence Tomography Image

      Predicting Macular Edema Recurrence from Spatio-Temporal Signatures in Optical Coherence Tomography Image

      Abstract: Prediction of treatment responses from available data is key to optimizing personalized treatment. Retinal diseases are treated over long periods and patients’ response patterns differ substantially, ranging from a complete response to a recurrence of the disease and need for re-treatment at different intervals. Linking observable variables in high-dimensional observations to outcome is challenging. In this paper, we present and evaluate two different data-driven machine learning approaches operating in a high-dimensional feature space: sparse logistic regression and Random Forests based extra trees (ET). Both identify spatio-temporal signatures based on retinal thickness features measured in longitudinal spectral-domain optical coherence tomography ...

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    10. Reproducibility of Retinal Thickness Measurements across Spectral-Domain Optical Coherence Tomography Devices using Iowa Reference Algorithm

      Reproducibility of Retinal Thickness Measurements across Spectral-Domain Optical Coherence Tomography Devices using Iowa Reference Algorithm

      PURPOSE: Establishing and obtaining consistent quantitative indices of retinal thickness from a variety of clinically used Spectral-Domain Optical Coherence Tomography scanners. DESIGN: Retinal images from five Spectral-Domain Optical Coherence Tomography scanners were used to determine total retinal thickness with scanner-specific correction factors establishing consistency of thickness measurement across devices. PARTICIPANTS: 55 Fovea-centered Spectral-Domain Optical Coherence Tomography volumes from eleven subjects were analyzed, obtained from Cirrus HD-OCT, RS-3000, Heidelberg Spectralis, RTVue and Topcon2000, seven subjects with retinal diseases and four normal controls. METHOD: The Iowa Reference Algorithm measured total retinal thickness. Nonlinear model of total retinal thickness measurement comparisons was derived ...

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    11. Multivendor Spectral-Domain Optical Coherence Tomography Dataset, Observer Annotation Performance Evaluation, and Standardized Evaluation Framework for Intraretinal Cystoid Fluid Segmentation

      Multivendor Spectral-Domain Optical Coherence Tomography Dataset, Observer Annotation Performance Evaluation, and Standardized Evaluation Framework for Intraretinal Cystoid Fluid Segmentation

      Development of image analysis and machine learning methods for segmentation of clinically significant pathology in retinal spectral-domain optical coherence tomography (SD-OCT), used in disease detection and prediction, is limited due to the availability of expertly annotated reference data. Retinal segmentation methods use datasets that either are not publicly available, come from only one device, or use different evaluation methodologies making them difficult to compare. Thus we present and evaluate a multiple expert annotated reference dataset for the problem of intraretinal cystoid fluid (IRF) segmentation, a key indicator in exudative macular disease. In addition, a standardized framework for segmentation accuracy evaluation ...

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    12. Improve synthetic retinal OCT images with present of pathologies and textural information

      Improve synthetic retinal OCT images with present of pathologies and textural information

      The lack of noise free Optical Coherence Tomography (OCT) images makes it challenging to quantitatively evaluate performance of image processing methods such as denoising methods. The synthetic noise free OCT images are needed to evaluate performance of image processing methods. The current synthetic methods fail to generate synthetic images that represent real OCT images with present of pathologies. They cannot correctly imitate real OCT data due to a tendency to smooth the data, losing texture information and even, pathologies such as cysts are simply smoothed away by these methods. The first aim of this paper is to use mathematical models ...

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    13. Geodesic denoising for optical coherence tomography images

      Geodesic denoising for optical coherence tomography images

      Optical coherence tomography (OCT) is an optical signal acquisition method capturing micrometer resolution, cross-sectional three-dimensional images. OCT images are used widely in ophthalmology to diagnose and monitor retinal diseases such as age-related macular degeneration (AMD) and Glaucoma. While OCT allows the visualization of retinal structures such as vessels and retinal layers, image quality and contrast is reduced by speckle noise, obfuscating small, low intensity structures and structural boundaries. Existing denoising methods for OCT images may remove clinically significant image features such as texture and boundaries of anomalies. In this paper, we propose a novel patch based denoising method, Geodesic Denoising ...

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    14. Choroidal thickness maps from spectral domain and swept source optical coherence tomography: algorithmic versus ground truth annotation

      Choroidal thickness maps from spectral domain and swept source optical coherence tomography: algorithmic versus ground truth annotation

      Background/aims The purpose of the study was to create a standardised protocol for choroidal thickness measurements and to determine whether choroidal thickness measurements made on images obtained by spectral domain optical coherence tomography (SD-OCT) and swept source (SS-) OCT from patients with healthy retina are interchangeable when performed manually or with an automatic algorithm. Methods 36 grid cell measurements for choroidal thickness for each volumetric scan were obtained, which were measured for SD-OCT and SS-OCT with two methods on 18 eyes of healthy volunteers. Manual segmentation by experienced retinal graders from the Vienna Reading Center and automated segmentation on ...

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    15. Choroidal line scan measurements in swept-source optical coherence tomography as surrogates for volumetric thickness assessment - American Journal of Ophthalmology

      Choroidal line scan measurements in swept-source optical coherence tomography as surrogates for volumetric thickness assessment - American Journal of Ophthalmology

      Purpose To compare choroidal thickness of different areas on swept-source optical coherence tomography (SS-OCT) line and cube scans for their interchangeable use. Design Validity analysis. Methods SS-OCT line and cube scans were obtained from 21 patients with various choroidal thicknesses. Subfoveal centerpoint choroidal thickness, mean central millimeter choroidal thickness and mean 6-mm area choroidal thicknesses were obtained from both eyes by two independent graders in a reading center setting. Cross-correlations were performed using Passing and Bablok regression models. A 95% confidence interval of slope that included 1 was considered to indicate no significant difference. Average choroidal thickness of centerpoint, early ...

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    16. Automated retinal fovea type distinction in spectral-domain optical coherence tomography of retinal vein occlusion

      Automated retinal fovea type distinction in spectral-domain optical coherence tomography of retinal vein occlusion

      Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high- resolution, three-dimensional (3D) cross-sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD), glaucoma and retinal vein occlusion (RVO). Disease diagnosis, assessment, and treatment will require a patient to undergo multiple OCT scans, possibly using multiple scanners, to accurately and precisely gauge disease activity, progression and treatment success. However, cross-vendor imaging and patient movement may result in poor scan spatial correlation potentially leading to ...

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    17. Quantitative comparison of macular segmentation performance using identical retinal regions across multiple spectral-domain optical coherence tomography instruments

      Quantitative comparison of macular segmentation performance using identical retinal regions across multiple spectral-domain optical coherence tomography instruments

      Purpose Comparison of optical coherence tomography (OCT) segmentation performance regarding technical accuracy and clinical relevance. Methods 29 eyes were imaged prospectively with Spectralis (Sp), Cirrus (Ci), 3D-OCT 2000 (3D) and RS-3000 (RS) OCTs. Raw data were evaluated in validated custom software. A 1 mm diameter subfield, centred on the fovea, was investigated to compare identical regions for each case. Segmentation errors were corrected on each B-scan enclosed in this subfield. Proportions of wrongly segmented A-scans were noted for inner and outer retinal boundaries. Centre point thickness (CPT) and central macular thickness (CMT) were compared before and after correction. Results Segmentation ...

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    18. Stable Registration of Pathological 3D SD-OCT Scans using Retinal Vessels

      Stable Registration of Pathological 3D SD-OCT Scans using Retinal Vessels

      We propose a multiple scanner vendor registration method for pathological retinal 3D spectral domain optical coherence tomography volumes based on Myronenko’s Coherent Point Drift and our automated vessel shadow segmentation. Coherent point drift is applied to the segmented retinal vessel point sets used as landmarks to generate the registration parameters required. In contrast to other registration methods, our solution incorporates a landmark detection and extraction method that specifically limits the extraction of false positives and a registration method capable of handling any such noise in the landmark point sets. Our experiments show modified Hausdorff distance is reduced by a ...

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    19. Three-dimensional automated choroidal volume assessment on standard spectral-domain optical coherence tomography and correlation with the level of diabetic macular edema

      Three-dimensional automated choroidal volume assessment on standard spectral-domain optical coherence tomography and correlation with the level of diabetic macular edema

      Purpose To measure choroidal thickness on spectral-domain optical coherence tomography (SD-OCT) images using automated algorithms and to correlate choroidal pathology with retinal changes due to diabetic macular edema (DME). Design Post-hoc analysis of multicenter clinical trial baseline data. Methods SD-OCT raster scans/fluorescein angiograms were obtained from 284 treatment naïve eyes of 142 patients with clinically significant DME and from 20 controls. Three-dimensional (3D) SD-OCT images were evaluated by a certified independent reading center analyzing retinal changes associated with diabetic retinopathy. Choroidal thicknesses were analyzed using a fully automated algorithm. Angiograms were assessed manually. Multiple endpoint correction according to ...

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    20. Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

      Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

      Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high reso- lution, three-dimensional (3D) cross sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD) and glaucoma. 1 Disease diagnosis, assessment, and treatment requires a patient to undergo multiple OCT scans, possibly using different scanning devices, to accurately and precisely gauge disease activity, progression and treatment success. However, the use of OCT imaging devices from different vendors, combined with patient movement may result in ...

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    1-20 of 20
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    Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices Three-dimensional automated choroidal volume assessment on standard spectral-domain optical coherence tomography and correlation with the level of diabetic macular edema Stable Registration of Pathological 3D SD-OCT Scans using Retinal Vessels Quantitative comparison of macular segmentation performance using identical retinal regions across multiple spectral-domain optical coherence tomography instruments Automated retinal fovea type distinction in spectral-domain optical coherence tomography of retinal vein occlusion Choroidal line scan measurements in swept-source optical coherence tomography as surrogates for volumetric thickness assessment - American Journal of Ophthalmology Choroidal thickness maps from spectral domain and swept source optical coherence tomography: algorithmic versus ground truth annotation Improve synthetic retinal OCT images with present of pathologies and textural information Reproducibility of Retinal Thickness Measurements across Spectral-Domain Optical Coherence Tomography Devices using Iowa Reference Algorithm Predicting Macular Edema Recurrence from Spatio-Temporal Signatures in Optical Coherence Tomography Image Normative data and associations of Optical Coherence Tomography Angiography measurements of the macula: The Singapore Malay Eye Study Automatic Segmentation and Measurement of Choroid Layer in High Myopia for OCT Imaging Using Deep Learning