1. Articles from Haoyu Chen

    1-22 of 22
    1. Effect of optic disc–fovea distance on the normative classifications of macular inner retinal layers as assessed with OCT in healthy subjects

      Effect of optic disc–fovea distance on the normative classifications of macular inner retinal layers as assessed with OCT in healthy subjects

      Purpose To determine the influence of the optic disc–fovea distance (DFD) on the normative classifications based on thickness measurements of macular inner retinal layers with spectral-domain optical coherence tomography (OCT) in healthy subjects. Methods A total of 182 eyes from 182 healthy subjects were included (mean (SD) spherical equivalent −0.8 (1.9) dioptres). We performed macula and optic disc imaging with the Topcon 3D OCT 2000. The thickness of the macular inner retinal layers (macular retinal nerve fibre layer (mRNFL), ganglion cell-inner plexiform layer (GCIPL) and both combined (ganglion cell complex; GCC)) and the corresponding classifications based on ...

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    2. Relationship between Optical Intensity on Optical Coherence Tomography and Retinal Ischemia in Branch Retinal Vein Occlusion

      Relationship between Optical Intensity on Optical Coherence Tomography and Retinal Ischemia in Branch Retinal Vein Occlusion

      Branch retinal vein occlusion (BRVO) may be complicated with retinal ischemia in some cases. The purpose of the current study is to investigate the relationship between optical intensity on optical coherence tomography (OCT) and retinal ischemia in BRVO. Twenty-seven eyes diagnosed with BRVO without macular edema were classified into two groups based on the presence or absence of retinal ischemia. The optical intensity of inner retinal layers and photoreceptor inner segment ellipsoid zone/retinal pigment epithelium layer (ISe/RPE) in the affected and unaffected regions were measured on OCT. Their ratio (Optical intensity ratio, OIR) was calculated and compared between ...

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    3. Repeatability, interocular correlation and agreement of quantitative swept-source optical coherence tomography angiography macular metrics in healthy subjects

      Repeatability, interocular correlation and agreement of quantitative swept-source optical coherence tomography angiography macular metrics in healthy subjects

      Purpose To investigate the repeatability, interocular correlation and agreement of quantitative swept-source optical coherence tomography angiography (SS-OCTA) metrics in healthy subjects. Methods Thirty-three healthy normal subjects were enrolled. The macula was scanned four times by an SS-OCTA system using the 3 mm×3 mm mode. The superficial capillary map images were analysed using a MATLAB program. A series of parameters were measured: foveal avascular zone (FAZ) area, FAZ perimeter, FAZ circularity, parafoveal vessel density, fractal dimension and vessel diameter index (VDI). The repeatability of four scans was determined by intraclass correlation coefficient (ICC). Then the averaged results were analysed for ...

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    4. Shared-hole graph search with adaptive constraints for 3D optic nerve head optical coherence tomography image segmentation

      Shared-hole graph search with adaptive constraints for 3D optic nerve head optical coherence tomography image segmentation

      Optic nerve head (ONH) is a crucial region for glaucoma detection and tracking based on spectral domain optical coherence tomography (SD-OCT) images. In this region, the existence of a “hole” structure makes retinal layer segmentation and analysis very challenging. To improve retinal layer segmentation, we propose a 3D method for ONH centered SD-OCT image segmentation, which is based on a modified graph search algorithm with a shared-hole and locally adaptive constraints. With the proposed method, both the optic disc boundary and nine retinal surfaces can be accurately segmented in SD-OCT images. An overall mean unsigned border positioning error of 7 ...

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    5. Automated segmentation of choroidal neovascularization in optical coherence tomography images using multi-scale convolutional neural networks with structure prior

      Automated segmentation of choroidal neovascularization in optical coherence tomography images using multi-scale convolutional neural networks with structure prior

      Automated segmentation of choroidal neovascularization (CNV) in optical coherence tomography (OCT) images plays an important role for the treatment of CNV disease. This paper proposes multi-scale convolutional neural networks with structure prior to segment CNV from OCT data. The proposed framework consists of two stages. In the first stage, the structure prior learning method based on sparse representation-based classification and the local potential function is developed to capture the global spatial structure and local similarity structure prior. The obtained prior can be used to improve the distinctiveness between CNV and background patches. In the second stage, multi-scale CNN model with ...

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    6. Automated framework for intraretinal cystoid macular edema segmentation in three-dimensional optical coherence tomography images with macular hole

      Automated framework for intraretinal cystoid macular edema segmentation in three-dimensional optical coherence tomography images with macular hole

      Cystoid macular edema (CME) and macular hole (MH) are the leading causes for visual loss in retinal diseases. The volume of the CMEs can be an accurate predictor for visual prognosis. This paper presents an automatic method to segment the CMEs from the abnormal retina with coexistence of MH in three-dimensional-optical coherence tomography images. The proposed framework consists of preprocessing and CMEs segmentation. The preprocessing part includes denoising, intraretinal layers segmentation and flattening, and MH and vessel silhouettes exclusion. In the CMEs segmentation, a three-step strategy is applied. First, an AdaBoost classifier trained with 57 features is employed to generate ...

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    7. Nonrigid registration of 3D longitudinal optical coherence tomography volumes with choroidal neovascularization

      Nonrigid registration of 3D longitudinal optical coherence tomography volumes with choroidal neovascularization

      In this paper, we propose a 3D registration method for retinal optical coherence tomography (OCT) volumes. The proposed method consists of five main steps: First, a projection image of the 3D OCT scan is created. Second, the vessel enhancement filter is applied on the projection image to detect vessel shadow. Third, landmark points are extracted based on both vessel positions and layer information. Fourth, the coherent point drift method is used to align retinal OCT volumes. Finally, a nonrigid B-spline-based registration method is applied to find the optimal transform to match the data. We applied this registration method on 15 ...

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    8. Graph search: active appearance model based automated segmentation of retinal layers for optic nerve head centered OCT images

      Graph search: active appearance model based automated segmentation of retinal layers for optic nerve head centered OCT images

      In this paper, a novel approach combining the active appearance model (AAM) and graph search is proposed to segment retinal layers for optic nerve head(ONH) centered optical coherence tomography(OCT) images. The method includes two parts: preprocessing and layer segmentation. During the preprocessing phase, images is first filtered for denoising, then the B-scans are flattened. During layer segmentation, the AAM is first used to obtain the coarse segmentation results. Then a multi-resolution GS–AAM algorithm is applied to further refine the results, in which AAM is efficiently integrated into the graph search segmentation process. The proposed method was tested ...

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    9. Change of Optical Intensity during Healing Process of Corneal Wound on Anterior Segment Optical Coherence Tomography

      Change of Optical Intensity during Healing Process of Corneal Wound on Anterior Segment Optical Coherence Tomography

      The purpose of this study is to investigate the process of corneal wound healing after penetrating injury with the change in optical intensity on anterior segment optical coherence tomography (AS-OCT) and to investigate factors associated with severity of corneal scar. Forty-seven eyes from 47 patients with repaired corneal laceration were included. AS-OCT was performed on 1day, 1week, 1, 3 and 6 months after primary repair. Internal aberrations of wound edges were observed on AS-OCT images. Parameters including height of steps, width of gaps, maximal corneal thickness, area and optical intensity of corneal wound/scar were measured. The relationship between the ...

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      Mentions: Haoyu Chen
    10. A framework for classification and segmentation of branch retinal artery occlusion in SD-OCT

      A framework for classification and segmentation of branch retinal artery occlusion in SD-OCT

      Branch retinal artery occlusion (BRAO) is an ocular emergency which could lead to blindness. Quantitative analysis of BRAO region in the retina is very needed to assessment of the severity of retinal ischemia. In this paper, a fully automatic framework was proposed to classify and segment BRAO based on 3D spectral-domain optical coherence tomography (SD-OCT) images. To the best of our knowledge, this is the first automatic 3D BRAO segmentation framework. First, a support vector machine (SVM) based classifier is designed to differentiate BRAO into acute phase and chronic phase, and the two types are segmented separately. To segment BRAO ...

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      Mentions: Haoyu Chen
    11. CORRELATION OF OPTICAL INTENSITY ON OPTICAL COHERENCE TOMOGRAPHY AND VISUAL OUTCOME IN CENTRAL RETINAL ARTERY OCCLUSION

      CORRELATION OF OPTICAL INTENSITY ON OPTICAL COHERENCE TOMOGRAPHY AND VISUAL OUTCOME IN CENTRAL RETINAL ARTERY OCCLUSION

      Purpose: To investigate the relationship between optical coherence tomography (OCT) characteristics at baseline and visual outcome in central retinal artery occlusion (CRAO). Methods: The medical charts and OCT images of patients with central retinal artery occlusion with follow-up for more than 90 days were reviewed. Optical intensities of inner retinal layers, outer nuclear layers, and photoreceptor/retinal pigment epithelium were measured using Image J software. Optical intensity ratio was calculated as the optical intensity of inner retinal layers divided by that of photoreceptor/retinal pigment epithelium. Retinal thickness over the nine early treatment diabetic retinopathy study regions was automatically calculated ...

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      Mentions: Haoyu Chen
    12. Profile and Determinants of Retinal Optical Intensity in Normal Eyes with Spectral Domain Optical ...

      Profile and Determinants of Retinal Optical Intensity in Normal Eyes with Spectral Domain Optical ...

      Purpose To investigate the profile and determinants of retinal optical intensity in normal subjects using 3D spectral domain optical coherence tomography (SD OCT). Methods A total of 231 eyes from 231 healthy subjects ranging in age from 18 to 80 years were included and underwent a 3D OCT scan. Forty-four eyes were randomly chosen to be scanned by two operators for reproducibility analysis. Distribution of optical intensity of each layer and regions specified by the Early Treatment of Diabetic Retinopathy Study (ETDRS) were investigated by analyzing the OCT raw data with our automatic graph-based algorithm. Univariate and multivariate analyses were ...

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    13. Prediction of spontaneous closure of traumatic macular hole with spectral domain optical coherence tomography

      Prediction of spontaneous closure of traumatic macular hole with spectral domain optical coherence tomography

      It has been known that some traumatic macular holes can close spontaneously. However, knowledge about the types of macular hole that can close spontaneously is limited. In this retrospective study, we investigated patients with traumatic macular hole who were followed-up for at least 6 months without any surgical intervention. Clinical data and spectral domain optical coherence tomography (SD-OCT) images were compared between groups with and without macular hole closure. Overall, 27 eyes were included. Spontaneous closure of macular hole was observed in 10 (37.0%) eyes. The holes with spontaneous closure had smaller minimum diameter (244.9 ± 114.4 vs ...

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    14. Automated segmentation of serous pigment epithelium detachment in SD-OCT images

      Automated segmentation of serous pigment epithelium detachment in SD-OCT images

      Pigment epithelium detachment (PED) is an important clinical manifestation of multiple chorio-retinal disease processes, which can cause the loss of central vision. A 3-D method is proposed to automatically segment serous PED in SD-OCT images. The proposed method consists of five steps: first, a curvature anisotropic diffusion filter is applied to remove speckle noise. Second, the graph search method is applied for abnormal retinal layer segmentation associated with retinal pigment epithelium (RPE) deformation. During this process, Bruch’s membrane, which doesn’t show in the SD-OCT images, is estimated with the convex hull algorithm. Third, the foreground and background seeds ...

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    15. Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography for central retinal artery occlusion

      Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography for central retinal artery occlusion

      Optical coherence tomography (OCT) provides not only morphological information but also information about layer-specific optical intensities, which may represent the underlying tissue properties. The purpose of this study is to quantitatively investigate the optical intensity of each retinal layers in central retinal artery occlusion (CRAO). Twenty-nine CRAO cases at acute phase and 33 normal controls were included. Macula-centered 3D OCT images were segmented with a fully-automated Iowa Reference Algorithm into 10 layers. Layer-specific mean intensities were determined and compared between the patient and control groups using multiple regression analysis while adjusting for age and optical intensity of the entire region ...

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    16. Automated 3-D Retinal Layer Segmentation of Macular Optical Coherence Tomography Images with Serous Pigment Epithelial Detachments

      Automated 3-D Retinal Layer Segmentation of Macular Optical Coherence Tomography Images with Serous Pigment Epithelial Detachments

      Automated retinal layer segmentation of optical coherence tomography (OCT) images has been successful for normal eyes but becomes challenging for eyes with retinal diseases if the retinal morphology experiences critical changes. We pro-pose a method to automatically segment the retinal layers in 3 - D OCT data with serous retinal pigment epithelial detachments (PED), which is a prominent feature of many chorioretinal disease processes. The proposed framework consists of the following steps: fast denoising and B-scan alignment, multi-resolution graph search based surface detection, PED region detection and surface correction above the PED region. The proposed technique was evaluated on a dataset ...

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    17. Comparison of Retinal Thickness Measurements of Normal Eyes between Topcon Algorithm and a Graph Based Algorithm

      Comparison of Retinal Thickness Measurements of  Normal Eyes between Topcon Algorithm and a Graph  Based Algorithm

      To assess the agreement between Topcon built-in algorithm and our developed graph based algorithm, the retinal thickness of 9-sectors on an Early Treatment of Diabetic Retinopathy Study(ETDRS) chart measurements for normal subjects was compared. A total of fifty eyes were enrolled in this study. The overall and sectoral thickness on ETDRS chart were calculated using Topcon built-in algorithm and our developed three-dimensional graph based algorithm. Correlation analysis and agreement analysis were performed between the commercial algorithm and our algorithm. A high degree of correlation was found between the results obtained from the two methods was from 0.856 to ...

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    18. Comparison of the optical coherence tomographic characters between acute Vogt-Koyanagi-Harada disease and acute central serous chorioretinopathy

      Comparison of the optical coherence tomographic characters between acute Vogt-Koyanagi-Harada disease and acute central serous chorioretinopathy

      Background Acute Vogt-Koyanagi-Harada (VKH) disease and acute central serous chorioretinopathy (CSCR) are two common disorders with serous retinal detachment caused by dysfunction of choroid. The purpose of this study is to compare the morphological changes of these two diseases with spectral domain optical coherence tomography (SD-OCT). Methods In this retrospective comparative study, the SD-OCT images of 65 eyes with acute VKH and 52 eyes with acute CSCR were reviewed for the presence of subretinal fluid, folds of retinal pigment epithelial (RPE), fluctuation of internal limiting membrane (ILM), subretinal septa, retinal pigment epithelium detachment (PED) and bulge of RPE. The foveal ...

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    19. Support vector machine based IS/OS disruption detection from SD-OCT images

      Support vector machine based IS/OS disruption detection from SD-OCT images

      In this paper, we sought to find a method to detect the Inner Segment /Outer Segment (IS/OS)disruption region automatically. A novel support vector machine (SVM) based method was proposed for IS/OS disruption detection. The method includes two parts: training and testing. During the training phase, 7 features from the region around the fovea are calculated. Support vector machine (SVM) is utilized as the classification method. In the testing phase, the training model derived is utilized to classify the disruption and non-disruption region of the IS/OS, and calculate the accuracy separately. The proposed method was tested on ...

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      Mentions: Haoyu Chen
    20. Quantitative Analysis of Retinal Layer Optical Intensities on Three-Dimensional Optical Coherence Tomography

      Quantitative Analysis of Retinal Layer Optical Intensities on Three-Dimensional Optical Coherence Tomography

      Purpose. To investigate the optical intensities of all retinal layers on three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) in normal subjects using an automatic measurement. Methods. Forty normal subjects underwent Topcon 3D OCT-1000 macula-centered scan. The raw data were automatically segmented into 10 layers using the 3D graph search approach. Then the mean and standard deviation of intensities of each layer were calculated. The image quality index was given by the OCT software. Correlation analysis was performed between the optical intensities in each layer and image quality and subject's age. Results. The correlation of optical intensities was strong from ...

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    21. Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography

      Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography

      Purpose: To investigate the optical intensities of all retinal layers on 3D spectral domain optical coherence tomography (SD-OCT) in normal subjects using an automatic measurement. Methods: Forty normal subjects underwent Topcon 3D-OCT 1000 macula-centered scan. The raw data was automatically segmented into 10 layers using the 3D graph search approach. Then the mean and standard deviation of intensities of each layer were calculated. The image quality index was given by the OCT software. Correlation analysis was performed between the optical intensities in each layer with the image quality and subject's age. Results: The correlation of optical intensities was strong ...

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    22. Prediction of Visual Prognosis With Spectral-Domain Optical Coherence Tomography in Outer Retinal Atrophy Secondary to Closed Globe Trauma

      Prediction of Visual Prognosis With Spectral-Domain Optical Coherence Tomography in Outer Retinal Atrophy Secondary to Closed Globe Trauma

      Purpose: To investigate the structural features of outer retinal atrophy secondary to closed globe trauma and their correlation with visual prognosis, using spectral-domain optical coherence tomography (OCT). Methods: In this retrospective study, patients with outer retinal atrophy secondary to closed globe trauma were examined with Topcon 3D OCT-1000. The foveal thickness was measured. The severity of outer retinal atrophy was graded into three levels: disruption of inner/outer segment layer, reduced thickness of outer nuclear layer, and disappearance of outer nuclear layer. Cases with >180 days of follow-up were included. The correlations between OCT features and best-corrected visual acuity at ...

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    1-22 of 22
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    1. (22 articles) Haoyu Chen
    2. (12 articles) The Chinese University of Hong Kong
    3. (11 articles) Soochow University
    4. (6 articles) Topcon Medical Systems
    5. (4 articles) University of Iowa
    6. (4 articles) Milan Sonka
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    Prediction of Visual Prognosis With Spectral-Domain Optical Coherence Tomography in Outer Retinal Atrophy Secondary to Closed Globe Trauma Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography Quantitative Analysis of Retinal Layer Optical Intensities on Three-Dimensional Optical Coherence Tomography Support vector machine based IS/OS disruption detection from SD-OCT images Comparison of the optical coherence tomographic characters between acute Vogt-Koyanagi-Harada disease and acute central serous chorioretinopathy Comparison of Retinal Thickness Measurements of  Normal Eyes between Topcon Algorithm and a Graph  Based Algorithm Automated 3-D Retinal Layer Segmentation of Macular Optical Coherence Tomography Images with Serous Pigment Epithelial Detachments Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography for central retinal artery occlusion Prediction of spontaneous closure of traumatic macular hole with spectral domain optical coherence tomography Profile and Determinants of Retinal Optical Intensity in Normal Eyes with Spectral Domain Optical ... Repeatability, reproducibility and agreement of foveal avascular zone measurements using three different optical coherence tomography angiography devices Subclinical hypothyroidism is associated with lipid-rich plaques in patients with coronary artery disease as assessed by optical coherence tomography