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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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A Review: Tomography Systems in Medical and Industrial Processes
摘要： Conventional methods previously guided reading meter to monitor the process and steps must be taken to interpret the readings and what need to adjustment be implemented. With the use of the method tomography, imaging process that displays the contents of the flow in the pipe or vessel during the process of giving analysts in real time quickly. By so corrective action can be done at a fast rate. The image will be formed from the trajectory of the object or sensor plane passing through the tomographic system. Use tomography method can be adapted to the process or the materials to be monitored. This paper examines the use of tomography in medical and industrial sectors. For use in the medical field such as looking at the structure of tissue in the body, can be used to detect cancerous elements tomography method comprising the X-ray, optical coherence tomography (OCT), Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI), and ultrasound. The industrial sector consists of Optical Coherence Tomography (OCT), Electrical Impedance Tomography (EIT), Electrical Resistance Tomography (ERT), optical Capacitance Tomography (ECT), and Tomography Ultrasonic (UT). This paper discusses the role, the use of concepts, basic design and development impact of the results of research conducted by previous researchers.
关键词： Tomography concept,application medical and industrial sector,operation
更新于2025-09-23 15:22:29
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Ultraviolet exposure of Gafchromic XR-RV3 and XR-SP2 films
摘要： Gafchromic film has been used for X-ray dose measurement in diagnostic examinations. Their use has been initiated for three-dimensional X-ray dose measurement by using the high-resolution characteristics of Gafchromic films in computed tomography. However, it is necessary to solve the problem of nonuniform thickness in the active layers of Gafchromic films. A double exposure technique using X-rays is performed in therapeutic radiology; it is difficult to use in a diagnostic examination because of the heel effect. Therefore, it is suggested that ultraviolet (UV) rays be substituted for X-rays. However, the appropriate UV wavelength is unknown. In this study, we aimed to determine which UV wavelengths are effective to expose Gafchromic XR-RV3 and XR-SP2. UV lamps with peak wavelengths of 245 nm, 310 nm, and 365 nm were used. The three UV wavelengths were used to irradiate Gafchromic XR-RV3 and XR-SP2 films for 60 min, and irradiation was repeated every 60 min for 600 min thereafter. Films were scanned after each irradiation period on a flatbed scanner. The images were split into their red-green-blue components, and red images were stored using ImageJ version 1.44o image analysis software. Regions of interest (ROI), 0.5 inches in diameter, were placed at the centers of the subtracted Gafchromic film images, and graphs of UV irradiation duration and mean pixel values were plotted. There were reactions to UV-A on both Gafchromic XR-RV3 and XR-SP2; those to UV-B were moderate. However, UV-C demonstrated few reactions with Gafchromic XR-RV3 and XR-SP2. From these results, irradiation with UV-A may be able to correct nonuniformity errors. Uniform UV-A irradiation of Gafchromic films with large areas is possible, and UV rays can be used as a substitute for X-rays in the double exposure technique.
关键词： Gafchromic film,nonuniformity,high-resolution measurement,ultraviolet rays,computed tomography
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