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Kago-Eye2 software for semi-automated segmentation of subfoveal choroid of optical coherence tomographic images
摘要： Purpose To determine the capabilities of the “Kago-Eye2” software to semi-automatically segment the choroid in the optical coherence tomographic (OCT) images. Study design A cross-sectional, prospective study of 44 healthy volunteers. Methods The Kago-eye2 software was developed to detect the border between Choriocapillaris and Sattler’s layer (C–S) and between Sattler’s layer and Haller’s layer (S–H). The intra- and inter-grader agreements were determined for the segmentations made with semi-automated and manual analysis using the Kago-Eye2 software. The inter-method agreements were determined for two independent graders. Results Forty-four right eyes of 44 heathy volunteers (22 men) with a mean age of 35.0 ± 8.8 years were studied. The intra-grader agreement of the C–S border was 0.97 for grader 1 and 0.892 for grader 2 for the manual segmentation, and 0.908 for grader 1 and 0.842 for grader 2 for the Kago-Eye2 segmentation. For the S–H border, the intra-grader agreement was 0.96 for grader 1 and 0.981 for grader 2 for manual segmentation and 0.855 for grader 1 and 0.839 for grader 2 with the Kago-Eye2. For the C–S and S–H border, the inter-grader agreement was 0.548 and 0.902 for manual segmentation and 0.947 and 0.833 for the Kago-Eye2. The inter-method agreement was 0.565 for the C–S border and 0.759 for the S–H border. Conclusion The Kago-Eye2 software can segment the layers of the subfoveal choroid with good reproducibility and repeatability. We conclude that the Kago-Eye2 software can be used for semi-automatic segmentation of the choroidal layers.
关键词： Choroid,Kago-Eye2,Image binarization,EDI-OCT
更新于2025-09-10 09:29:36
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Trou maculaire post traumatique chez un enfant de six ans: documentation par OCT
摘要： Les trous maculaires post-traumatiques sont, chez l'enfant, la première cause de trou maculaire, contrairement à celles de l'adulte. La tomographie en cohérence optique permet désormais un suivi plus objectif de ces déchirures rétiniennes. Nous rapportons le cas d'un enfant de 6 ans victime d'un traumatisme contusif de l'oeil droit avec cataracte post traumatique, l'examen du fond d'oeil a montré un trou fovéolaire d'environ un tiers du diamètre papillaire avec des plis rétiniens de part et d'autre de la lésion. L'OCT montrait un trou fovéolaire de pleine épaisseur. L'acuité visuelle était limitée à compte les doigts de près. Une surveillance régulière durant 6 mois et appuyée par l'OCT à objectiver la persistance du trou maculaire. Les trous maculaire secondaires sont majoritairement causés par des traumatismes du globe oculaire de cinétique violente. Dans ce cas, l'origine du trou maculaire post-contusif est liée à la déformation brutale du globe oculaire, lors de la compression antéro-postérieure avec étirement de la rétine. Ces forces de traction rétiniennes transversales entra?nent la rupture de la macula (zone de fragilité du p?le postérieur rétinien). Il existe une proportion des trous maculaires post traumatiques qui cicatrisent spontanément, la petite taille du trou (200 μm) favorise ces fermetures spontanées, ce qui n'est pas le cas de notre patient.
关键词： Trou maculaire,rétinographie,OCT
更新于2025-09-10 09:29:36
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Visualization of the pulp chamber roof and residual dentin thickness by spectral-domain optical coherence tomography in vitro
摘要： The aim of this study was to evaluate the ability of spectral-domain optical coherence tomography (SD-OCT) to display the roof of the pulp chamber and to estimate the residual dentin thickness (RDT) of the pulp complex. The roots of 20 extracted human molars were embedded in epoxy resin, and crowns were longitudinally sectioned in the mesial-distal direction, exposing the pulp chamber. The coronal part of the crown was removed up to an RDT to the pulp chamber roof of 2 mm. Samples were imaged by SD-OCT from coronal view and by light microscopy (LM) in the sagittal plane. Using a microtome, dentin was subsequently removed in four levels from the occlusal aspect in steps of 250 μm. At each level, RDT was documented and measured by both methods. The data were compared (Spearman’s rho correlation coefficient, Wilcoxon signed-rank test). Using OCT, the roof of the pulp chamber was first displayed at a maximum RDT of 1.94 mm. The minimal RDT that could be imaged by OCT was 0.06 mm. Values from both methods were strongly correlated (r, 0.83–0.95; pi ≤ 0.05) and differed significantly for large RDTs (dentin levels 1, 2; pi < 0.05) but not for small RDTs (levels 3, 4; pi ≥ 0.226). The roof of the dental pulp chamber could be already visualized by SD-OCT with a RDT of 1.94 mm. Therefore, the method could be a useful diagnostic tool during the preparation of deep dentin cavities and might help to preserve the integrity of the pulp chamber.
关键词： Pulp protection,Residual dentin thickness,OCT,Dental pulp,Deep dentin cavities,Diagnosis
更新于2025-09-10 09:29:36
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New Interpretation of Multimodality Fundus Imaging for Retinal Cavernous Hemangioma
摘要： Objective: The aim of this study was to investigate the multimodality imaging features of retinal cavernous hemangiomas (RCHs). Materials and Methods: The clinical data of three patients with RCH were reviewed and the imaging findings were analyzed. Results: The color photographs of the fundus showed bead-like vesicles in the retina. Some vesicles showed plasma erythrocyte separation—with plasma on the top and erythrocytes at the bottom—which was consistently detected as high spontaneous fluorescence on fundus fluorescence angiography. Other vesicles were surrounded by thick walls and fibrous tissue, showing high spontaneous fluorescence, although they did not show any changes on fluorescence angiography. Optical coherence tomography (OCT) could not discriminate the different characteristics of the vesicles, but could clearly discriminate the appearance of the vesicles and their location on the retina, as well as other structural features. Conclusions: Fundus color photography, fundus fluorescein angiography, and OCT can aid in acquiring a better understanding of the structural features of cavernous hemangioma and its relationship with retinal vessels.
关键词： fluorescein angiography,fundus color photography,Fundus autofluorescence,Retinal cavernous hemangioma,OCT
更新于2025-09-10 09:29:36
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Optical coherence tomography angiography (OCTA) flow speed mapping technology for retinal diseases
摘要： Introduction: Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality for depth-resolved visualization of retinal vasculature. Angiographic data couples with structural data to generate a cube scan, from which en-face images of vasculature can be obtained at various axial positions. OCTA has expanded understanding of retinal vascular disorders and has primarily been used for qualitative analysis. Areas covered: Recent studies have explored the quantitative properties of OCTA, which would allow for objective assessment and follow-up of retinal pathologies. Various quantitative metrics have been developed, such as foveal avascular zone area and vessel density. However, quantitative assessment of the characteristics of retinal blood flow remains limited, as OCTA provides an image depicting either the presence or absence of flow at a particular region without information of relative velocities. The development of variable interscan time analysis (VISTA) overcomes this limitation. The VISTA algorithm generates a color-coded map of relative blood flow speeds. VISTA has already demonstrated utility in furthering our understanding of various retinal pathologies, such as geographic atrophy, choroidal neovascularization, aneurysmal type 1 neovascularization, and diabetic retinopathy. Expert commentary: VISTA, an OCTA flow speed mapping technique, may have a role in developing the utility of OCTA as a screening tool.
关键词： flow speed mapping,diabetic retinopathy,age-related macular degeneration,VISTA,quantitative OCTA,OCTA,Optical coherence tomography angiography,variable interscan time analysis,OCT
更新于2025-09-10 09:29:36
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Enhanced-Depth Imaging Optical Coherence Tomography of the Human Choroid In Vivo Compared With Histology After Enucleation
摘要： PURPOSE. This study compared in vivo enhanced-depth imaging optical coherence tomography (EDI-OCT) with ex vivo histology of the choroid in human eyes. METHODS. Three eyes in three patients with advanced iris melanoma without posterior segment involvement underwent EDI-OCT less than 24 hours prior to enucleation and, in one eye, immediately after enucleation. Following fixation in 4% buffered formaldehyde and paraffin embedding, serial sections of the whole eye were cut horizontally, mounted, stained with hematoxylin-eosin and digitized. Alignment between histology and EDI-OCT was made on landmarks such as retinal vessel, the foveal depression, ciliary arteries, drusen, and nevi. RESULTS. Intra- and interindividual variations in relative choroidal thickness were comparable between the two modalities. After histologic fixation of the three melanoma eyes, the fullness of the choroidal vessels was reduced and subfoveal choroid thickness reduced to 56%, 45%, and 56%, respectively, of its in vivo thickness on EDI-OCT. CONCLUSIONS. There were no identifiable discrepancies in choroidal structural patterns between clinical EDI-OCT and histologic sections except that after enucleation and histologic fixation choroidal thickness was reduced to roughly half of its in vivo value, a phenomenon that may reflect the high content of blood vessels in the choroid.
关键词： histology,choroid,EDI-OCT
更新于2025-09-10 09:29:36
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The Pattern of Visual Fixation Eccentricity and Instability in Optic Neuropathy and Its Spatial Relationship to Retinal Ganglion Cell Layer Thickness
摘要： The purpose of this study was to assess whether clinically useful measures of fixation instability and eccentricity can be derived from retinal tracking data obtained during optical coherence tomography (OCT) in patients with optic neuropathy (ON) and to develop a method for relating fixation to the retinal ganglion cell complex (GCC) thickness. Twenty-nine patients with ON underwent macular volume OCT with 30 seconds of confocal scanning laser ophthalmoscope (cSLO)-based eye tracking during fixation. Kernel density estimation quantified fixation instability and fixation eccentricity from the distribution of fixation points on the retina. Preferred ganglion cell layer loci (PGCL) and their relationship to the GCC thickness map were derived, accounting for radial displacement of retinal ganglion cell soma from their corresponding cones. Fixation instability was increased in ON eyes (0.21 deg2) compared with normal eyes (0.06982 deg2; P < 0.001), and fixation eccentricity was increased in ON eyes (0.488) compared with normal eyes (0.248; P ? 0.03). Fixation instability and eccentricity each correlated moderately with logMAR acuity and were highly predictive of central visual field loss. Twenty-six of 35 ON eyes had PGCL skewed toward local maxima of the GCC thickness map. Patients with bilateral dense central scotomas had PGCL in homonymous retinal locations with respect to the fovea. Fixation instability and eccentricity measures obtained during cSLO-OCT assess the function of perifoveal retinal elements and predict central visual field loss in patients with ON. A model relating fixation to the GCC thickness map offers a method to assess the structure–function relationship between fixation and areas of preserved GCC in patients with ON.
关键词： optic neuropathy,fixation,ganglion cell,OCT
更新于2025-09-10 09:29:36
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[IEEE 2018 International CET Conference on Control, Communication, and Computing (IC4) - Thiruvananthapuram, India (2018.7.5-2018.7.7)] 2018 International CET Conference on Control, Communication, and Computing (IC4) - Computerized Detection of Macular Edema Using OCT Images Based on Fractal Texture Analysis
摘要： Macular edema (ME) is a significant cause that results in blindness among majority. It happens due to the anomalous leakage and builds up of fluids within macular region. Anything that relates with the performance of eyes can drive the chances to become a ME patient. ME can occur as a downstream of eye related surgeries, degradation due to aging or any eye disorders causing inflammation. The main fact about ME that if the disease is not identified and diagnosed at the earlier stages, the chance of recovery is minimal and can ultimately affect the ability to see. One of the main causes of ME is the disease which can injure in the retina. Laser photocoagulation and blood vessels vitrectomy are the common method available now for diagnosing the disease. Optical Coherence Tomography alias OCT, an advanced imaging technique to capture retinal layer region. Different algorithms were implemented to detect ME from OCT images, but early detection of ME is not possible. This paper utilizes segmentation based fractal texture analysis (SFTA) to derive the feature vector. Graph based segmentation employs in the detection of layers and QDA classifies the ME images. This algorithm will help the ophthalmologist to treat the patient at early stages. The algorithm is deployed successfully on a macular edema dataset, with 97.5% accuracy rate.
关键词： layer detection,Graph shortest path,SFTA,thickness profile,OCT,Macular Edema,QDA
更新于2025-09-10 09:29:36
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Sequential phases of RGC axonal and somatic injury in EAE mice examined using DTI and OCT
摘要： Background: Clinical imaging modalities including optical coherence tomography (OCT) and di?usion tensor imaging (DTI) are vital in Multiple Sclerosis (MS), but their relationships during the di?erent phases of Retinal ganglion cell (RGC) degeneration are not clear. We hypothesize that initial injury in optic nerve causes axonal degeneration leading to RGC loss in retina, which can be characterized by a combination of DTI and OCT. Our objective was to examine the correlation between noninvasive and histological data to chronicle the degeneration pro?le of RGCs in the retina and optic nerve in a mouse model of MS. Materials and methods: Experimental Autoimmune Encephalomyelitis (EAE) was induced in 11 C57Bl/6 mice, with 8 mice reserved as controls. OCT and DTI was conducted 2–8 weeks after induction of EAE. The thickness of the retinal ganglion cell complex (GCC) was measured using OCT and compared to DTI indices measured in optic nerves. End-stage histology was used to quantify axon/myelin loss in the optic nerve and retinal thinning/RGC loss in the retina. Results: Signi?cant changes in DTI-derived Axial Di?usivity (AD, ?17.2%) and Trace Di?usivity (TR, ?18.3%) began after 2 weeks of EAE. Later signi?cant reductions in Fractional Anisotropy (FA) and AD, with increases in Radial Di?usion (RD) were apparent after 4 and 8 weeks. OCT-derived measures of GCC thickness were reduced after 4 weeks, and reached signi?cant reduction after 8 weeks. Among EAE mice, DTI (FA, AD and RD measures) and OCT measures were all signi?cantly correlated after 4 and 8 weeks. Among histology measures, RGC density (?23%), RGC size (?27%), and the number of SMI31+ axons (?54%) were reduced signi?cantly. DTI measures of FA and AD along with GCC thinning were the best independent predictors of axon loss. Conclusions: DTI and OCT measures are tightly correlated during the chronic phase of axonal degeneration (4–8 weeks) in EAE mice. After 8 weeks of EAE, both OCT and DTI measures are strong predictors of axon loss in the Optic Nerve.
关键词： longitudinal study,Optical coherence tomography (OCT),Retinal ganglion cell (RGC),Experimental Autoimmune Encephalomyelitis (EAE),Di?usion tensor imaging (DTI)
更新于2025-09-10 09:29:36
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In Vivo Three-Dimensional Characterization of the Healthy Human Lamina Cribrosa With Adaptive Optics Spectral-Domain Optical Coherence Tomography
摘要： To characterize the in vivo three-dimensional (3D) lamina cribrosa (LC) microarchitecture of healthy eyes using adaptive optics spectral-domain optical coherence tomography (AO-SDOCT). A multimodal retinal imaging system with a light source centered at 1050 nm and AO confocal scanning laser ophthalmoscopy was used in this study. One randomly selected eye from 18 healthy subjects was scanned in a 68 3 68 window centered on the LC. Subjects also underwent scanning with Cirrus HD-OCT. Lamina cribrosa microarchitecture was semiautomatically segmented and quanti?ed for connective tissue volume fraction (CTVF), beam thickness, pore diameter, pore area, and pore aspect ratio. The LC was assessed in central and peripheral regions of equal areas and quadrants and with depth. A linear mixed effects model weighted by the fraction of visible LC was used to compare LC structure between regions. The nasal quadrant was excluded due to poor visualization. The central sector showed greater CTVF and thicker beams as compared to the periphery (P < 0.01). Both superior and inferior quadrants showed greater CTVF, pore diameter, and pore mean area than the temporal quadrant (P < 0.05). Depth analysis showed that the anterior and posterior aspects of the LC contained smaller pores with greater density and thinner beams as compared to the middle third (P < 0.05). The anterior third also showed a greater CTVF than the middle third (P < 0.05). In vivo analysis of healthy eyes using AO-SDOCT showed signi?cant, albeit small, regional variation in LC microarchitecture by quadrant, radially, and with depth, which should be considered in further studies of the LC.
关键词： structure,in vivo,OCT
更新于2025-09-10 09:29:36