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[IEEE 2018 3rd International Conference on Pattern Analysis and Intelligent Systems (PAIS) - Tebessa, Algeria (2018.10.24-2018.10.25)] 2018 3rd International Conference on Pattern Analysis and Intelligent Systems (PAIS) - A system for the automatic detection of glaucoma using retinal images
摘要： Glaucoma is an optic neuropathy and it principal cause of blindness in the world. In this paper, a system able to treat and analyze the Visual Field (VF) images and Optical Coherence Tomography of the Ganglion Cell Layer (OCT-GCL) images is proposed, in order to help early detection of glaucoma in its early stages. The proposed approach is based on calculating the percentage of healthy, sick and dead regions of VF and OCT-GCL images. In order to carry out this calculation, we combined the thresholding methods with morphological operators and median filter to extract all regions. These algorithms developed were tested on a set of images of a local database composed of 58 OCT-GCL images and 21 VF images. The results obtained are satisfactory and confirmed by experts in ophthalmology.
关键词： Optical coherence tomography of ganglion cell layer,Segmentation,Visual field,Glaucoma,Characterization
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - Guangzhou, China (2018.10.8-2018.10.12)] 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - Automated Segmentation of Esophagus Layers from OCT Images Using Fast Marching Method
摘要： Thickness of the esophagus is an important diagnostic marker for many esophagus diseases. While labeling boundaries by manual to compute each layer’s average thickness is time-consuming and subjective. In this paper, we present a new fully automatic algorithm which includes Fast Marching Method (FMM) and Fourth-Order Runge-Kutta method (RK4) to identify five esophagus layers on optical coherence tomography (OCT) images. FMM is used to calculate the weighted geodesic distance. In particular, the velocity function involved in this method combines vertical gradient, horizontal gradient and curvature so that it not only can divide flat borders but also irregular borders. RK4 is used to find the shortest path which is the boundary to be segmented. The experimental comparison between automatic and manual is performed on 400 healthy guinea pig esophagus OCT images and the mean absolute error thickness difference between them is less than 6 pixels while the value can reach to 9.41 pixels at most between two observers.
关键词： Runge-Kutta method,Optical Coherence Tomography,Fast Marching Method,Image processing,Esophagus Layer Segmentation
更新于2025-09-23 15:22:29
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Anterior segment optical coherence tomography (AS-OCT) as a new method of detecting copper deposits forming the Kayser-Fleischer ring in patients with Wilson disease
摘要： Purpose: Kayser–Fleischer ring pathognomonic for Wilson disease (WD) is formed of corneal copper deposits present predominantly within the anterior chamber angle at the Schwalbe’s line. The slit-lamp assessment commonly used as a standard of care cannot detect them early enough, as the angle view is obscured by the corneal limbus. The aim of the research was to evaluate the anterior segment optical coherence tomography (AS-OCT), as objective diagnostic assessment of copper deposits forming KF ring in patients with WD. Methods: Twenty-nine subjects (17 women) and twenty-nine controls (14 women) were enrolled and underwent slit lamp and AS-OCT assessment. Results: Kayser–Fleischer ring was not detected – either with a slit lamp or with AS-OCT – in any of the controls. Fifteen subjects presenting without KF ring at a slit-lamp examination were found to have a KF ring when examined with AS-OCT (p < 0.001), which confirms improved accuracy of AS-OCT, as compared to the slit-lamp examination. Conclusion: Our results support AS-OCT as a diagnostic procedure to offer better objectivity and accuracy as compared to a slit-lamp examination, both at the diagnostic stage and when monitoring changes in KF ring during medical therapy to assess its efficacy and patient compliance.
关键词： anterior segment optical coherence tomography,Kayser–Fleischer ring,Wilson disease,copper deposit
更新于2025-09-23 15:22:29
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Is Spectral-Domain Optical Coherence Tomography Always Able to Detect the Anti-Vascular Endothelial Growth Factor Action on Neovascular Membrane
摘要： Purpose: To show the presence of an active neovascular membrane in age-related macular degeneration even if optical coherence tomography (OCT) does not detect intra- or sub-retinal edema. Methods: This is a retrospective case report. During the follow-up after the intravitreal injection, 3 patients showed no intraretinal or subretinal edema by OCT; however, there was a progressive reduction in their visual acuity; thus, a fluorangiography (FA) examination was performed. Results: In these 3 cases, FA showed an active neovascular network. Conclusion: OCT could show a real reduction in the edema, but it is not always able to detect neovessel presence. Intravitreal injection could improve the vessel permeability without care and delete the neovascular network.
关键词： Intravitreal injection,Spectral-domain optical coherence tomography,Age-related macular degeneration
更新于2025-09-23 15:22:29
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Long-term Characterization of Retinal Degeneration in Royal College of Surgeons Rats Using Spectral-Domain Optical Coherence Tomography
摘要： PURPOSE. Prospective treatments for age-related macular degeneration and inherited retinal degenerations are commonly evaluated in the Royal College of Surgeons (RCS) rat before translation into clinical application. Historically, retinal thickness obtained through postmortem anatomic assessments has been a key outcome measure; however, utility of this measurement is limited because it precludes the ability to perform longitudinal studies. To overcome this limitation, the present study was designed to provide a baseline longitudinal quantification of retinal thickness in the RCS rat by using spectral-domain optical coherence tomography (SD-OCT). METHODS. Horizontal and vertical linear SD-OCT scans centered on the optic nerve were captured from Long-Evans control rats at P30, P60, P90 and from RCS rats between P17 and P90. Total retina (TR), outer nuclear layer+ (ONL+), inner nuclear layer (INL), and retinal pigment epithelium (RPE) thicknesses were quantified. Histologic sections of RCS retina obtained from P21 to P60 were compared to SD-OCT images. RESULTS. In RCS rats, TR and ONL+ thickness decreased significantly as compared to Long-Evans controls. Changes in INL and RPE thickness were not significantly different between control and RCS retinas. From P30 to P90 a subretinal hyperreflective layer (HRL) was observed and quantified in RCS rats. After correlation with histology, the HRL was identified as disorganized outer segments and the location of accumulated debris. CONCLUSIONS. Retinal layer thickness can be quantified longitudinally throughout the course of retinal degeneration in the RCS rat by using SD-OCT. Thickness measurements obtained with SD-OCT were consistent with previous anatomic thickness assessments. This study provides baseline data for future longitudinal assessment of therapeutic agents in the RCS rat.
关键词： MERTK,spectral-domain optical coherence tomography,inherited retinal degeneration,animal models,Royal College of Surgeons Rat
更新于2025-09-23 15:22:29
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The Evolution of the Plateau, an Optical Coherence Tomography Signature Seen in Geographic Atrophy
摘要： PURPOSE. Histologic details of progression routes to geographic atrophy (GA) in AMD are becoming available through optical coherence tomography (OCT). We studied the origins and evolution of an OCT signature called plateau in eyes with GA and suggested a histologic correlate. METHODS. Serial eye-tracked OCT scans and multimodal imaging were acquired from eight eyes of seven patients with GA and plateau signatures over a mean follow-up of 7.7 years (range, 3.7–11.6). The histology of unrelated donor eyes with AMD was reviewed. RESULTS. Drusenoid pigment epithelial detachment (PED) on OCT imaging progressed into wide-based mound-like signatures with flattened apices characterized by a hyporeflective yet heterogeneous interior and an overlying hyperreflective exterior, similar to outer retinal corrugations previously ascribed to persistent basal laminar deposit (BLamD) but larger. These new signatures are described as "plateaus." An initial increase of the PED volume and hyporeflectivity of its contents was followed by a decrease in PED volume and thinning of an overlying hyperreflective band attributable to the loss of the overlying RPE leaving persistent BLamD. Both imaging and histology revealed persistent BLamD with defects through which gliotic Müller cell processes pass. CONCLUSIONS. Plateaus can be traced back to drusenoid PEDs on OCT imaging. We hypothesize that during progressive RPE atrophy, Müller cell extension through focal defects in the residual persistent BLamD may contribute to the heterogeneous internal reflectivity of these entities. The role of Müller cell activation and extension in the pathogenesis of AMD should be explored in future studies.
关键词： geographic atrophy,multimodal imaging,optical coherence tomography,histology,drusenoid pigment epithelial detachment
更新于2025-09-23 15:22:29
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The Relationship Between High-Order Aberration and Anterior Ocular Biometry During Accommodation in Young Healthy Adults
摘要： PURPOSE. This study investigated the anterior ocular anatomic origin of high-order aberration (HOA) components using optical coherence tomography and a Shack-Hartmann wavefront sensor. METHODS. A customized system was built to simultaneously capture images of ocular wavefront aberrations and anterior ocular biometry. Relaxed, 2-diopter (D) and 4-D accommodative states were repeatedly measured in 30 young subjects. Custom software was used to correct optical distortions and measure biometric parameters from the images. RESULTS. The anterior ocular biometry changed during 2-D accommodation, in which central lens thickness, ciliary muscle thicknesses at 1 mm posterior to the scleral spur (CMT1), and the maximum value of ciliary muscle thickness increased significantly, whereas anterior chamber depth, CMT3, radius of anterior lens surface curvature (RAL), and radius of posterior lens surface curvature (RPL) decreased significantly. The changes in the anterior ocular parameters during 4-D accommodation were similar to those for the 2-D accommodation. Z0 4 decreased significantly during 2-D accommodation, and Z(cid:2)1 6 shifted to negative values during 4-D accommodation. The change in Z0 4 negatively correlated with those in CMT1, and the negative change in Z1 3 correlated with changes in RAL and CMT1. CONCLUSIONS. HOA components altered during step-controlled accommodative stimuli. Ciliary muscle first contracted during stepwise accommodation, which may directly contribute to the reduction of spherical aberration (SA). The lens morphology was then altered, and the change in anterior lens surface curvature was related to the variation of coma.
关键词： anterior ocular biometry,ciliary muscle,wavefront aberration,optical coherence tomography
更新于2025-09-23 15:22:29
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Comparison of Widefield and Circumpapillary Circle Scans for Detecting Glaucomatous Neuroretinal Thinning on Optical Coherence Tomography
摘要： Purpose: Our purpose was to compare the effectiveness of detecting progressive retinal nerve fiber layer (RNFL) thickness changes using widefield scans compared to circumpapillary circle scans derived from optic disc volume scans when using a manual region-of-interest (ROI) approach. Methods: In a prospective observational study, a total of 125 eyes diagnosed clinically with glaucoma or suspected glaucoma that had both widefield (12 3 9 mm) and optic disc (6 3 6 mm) scans obtained at least one year apart were included. Changes in the RNFL thickness between the two visits were evaluated within region(s) of observed or suspected glaucomatous damage, which were manually outlined after reviewing key features from each scan on the second visit (described as a manual ROI approach). Within ROI(s), changes in the widefield and circumpapillary RNFL thickness (wfRNFLROI and cpRNFLROI), as well as in the global circumpapillary RNFL thickness (cpRNFLG), were determined. The performance of these three methods for detecting progressive changes was compared using longitudinal signal-to-noise ratios (SNRs), whereby the rate of change determined by each method was normalized by individualized estimates of measurement variability and age-related change. Results: On average, the longitudinal SNRs for the wfRNFLROI, cpRNFLROI, and cpRNFLG methods were (cid:2)0.57, (cid:2)0.38, and (cid:2)0.23 y(cid:2)1, respectively, being significantly more negative for the wfRNFLROI than the latter two methods (P (cid:3) 0.009). Conclusions: Progressive RNFL thickness changes were more effectively detected on widefield optical coherence tomography (OCT) scans using a manual ROI approach compared to conventional derived circumpapillary circle scans.
关键词： glaucoma,widefield,optical coherence tomography,progression
更新于2025-09-23 15:22:29
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Effectiveness of a Qualitative Approach Toward Evaluating OCT Imaging for Detecting Glaucomatous Damage
摘要： Purpose: The purpose of this study was to determine whether a qualitative approach toward evaluating optical coherence tomography (OCT) imaging improves the ability to detect glaucomatous damage compared to a conventional metric of global circumpapillary retinal nerve fiber layer (cpRNFL) thickness. Methods: A total of 394 healthy eyes and 272 glaucoma eyes were evaluated. Glaucoma eyes were categorized as perimetric (156 eyes) based on a history of three or more consecutive abnormal 24-2 visual field tests or suspected glaucoma if they did not (116 eyes). Customized one-page reports derived using OCT volume scans of the optic disc and macula from these eyes were qualitatively graded for the probability of optic neuropathy affecting the eye. Results: The sensitivity of detecting perimetric glaucoma eyes with the global circumpapillary RNFL thickness metric and qualitative evaluation of the OCT imaging results were 86.5% and 95.5% at a specificity of 95%, being significantly higher for the latter (P < 0.001). There were seven eyes with perimetric glaucoma missed by the qualitative evaluation. Based upon examination of all available visual fields, at least four of these seven eyes had visual fields that either improved or had abnormalities that were inconsistent over time or with patterns of glaucomatous damage. Conclusions: Qualitative evaluation of OCT imaging results allows glaucoma eyes with repeatable visual field abnormalities to be detected with a high level of accuracy, performing better than a conventional summary metric of global cpRNFL thickness.
关键词： diagnosis,glaucoma,qualitative,optical coherence tomography
更新于2025-09-23 15:22:29
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Deep Learning-Based Automated Classification of Multi-Categorical Abnormalities From Optical Coherence Tomography Images
摘要： Purpose: To develop a new intelligent system based on deep learning for automatically optical coherence tomography (OCT) images categorization. Methods: A total of 60,407 OCT images were labeled by 17 licensed retinal experts and 25,134 images were included. One hundred one-layer convolutional neural networks (ResNet) were trained for the categorization. We applied 10-fold cross-validation method to train and optimize our algorithms. The area under the receiver operating characteristic curve (AUC), accuracy and kappa value were calculated to evaluate the performance of the intelligent system in categorizing OCT images. We also compared the performance of the system with results obtained by two experts. Results: The intelligent system achieved an AUC of 0.984 with an accuracy of 0.959 in detecting macular hole, cystoid macular edema, epiretinal membrane, and serous macular detachment. Specifically, the accuracies in discriminating normal images, cystoid macular edema, serous macular detachment, epiretinal membrane, and macular hole were 0.973, 0.848, 0.947, 0.957, and 0.978, respectively. The system had a kappa value of 0.929, while the two physicians’ kappa values were 0.882 and 0.889 independently. Conclusions: This deep learning-based system is able to automatically detect and differentiate various OCT images with excellent accuracy. Moreover, the performance of the system is at a level comparable to or better than that of human experts. This study is a promising step in revolutionizing current disease diagnostic pattern and has the potential to generate a significant clinical impact.
关键词： artificial intelligence,deep learning,optical coherence tomography,ResNet
更新于2025-09-23 15:22:29