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Optical coherence tomography angiography measured capillary density in the normal and glaucoma eyes
摘要： Purpose: To compare the diagnostic ability of optical coherence tomography angiography (OCT-A) derived radial peripapillary capillary (RPC) measured capillary density (CD) and inside the optic nerve head (ONH) CD measurements to differentiate between the normal and primary open angle glaucoma (POAG) eyes. Methods: AngioVue disc OCT-A images were obtained and assessed in 83 eyes of POAG patients and 74 age matched healthy eyes. RPC CD was quantitatively measured in the peripapillary area within 3.45 mm circle diameter around the ONH and inside the ONH in 8 equally divided sectors, using Bar – Selective Combination of Shifted Filter Responses method after the suppressing large vessels. Area under receiver operating characteristic (AUROC) curve was used to assess the diagnostic accuracy of the two scanning regions of CD to differentiate between the normal and POAG eyes. Results: The mean peripapillary RPC density (0.12 ± 0.03) and mean ONH CD (0.09 ± 0.03) were significantly lower in POAG eyes when compared to the normal eyes (RPC CD: 0.17 ± 0.05, p < 0.0001 and ONH CD 0.11 ± 0.02, p = 0.01 respectively). The POAG patients showed 29% reduction in the RPC CD and 19% reduction in the ONH CD when compared to the normal eyes. The AUROC for discriminating between healthy and glaucomatous eyes was 0.784 for mean RPC CD and 0.743 for the mean ONH CD. Conclusions: Diagnostic ability of OCT-A derived peripapillary CD and ONH CD was moderate for differentiating between the normal and glaucomatous eyes. Diagnostic ability of even the best peripapillary average and inferotemporal sector for RPC CD and average and superonasal sector for the ONH CD was moderate.
关键词： OCT-A,POAG,Peripapillary capillary density,ONH capillary density
更新于2025-09-23 15:23:52
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Deep structure tensor graph search framework for automated extraction and characterization of retinal layers and fluid pathology in retinal SD-OCT scans
摘要： Maculopathy is a group of retinal disorders that affect macula and cause severe visual impairment if not treated in time. Many computer-aided diagnostic methods have been proposed over the past that automatically detect macular diseases. However, to our best knowledge, no literature is available that provides an end-to-end solution for analyzing healthy and diseased macular pathology. This paper proposes a vendor-independent deep convolutional neural network and structure tensor graph search-based segmentation framework (CNN-STGS) for the extraction and characterization of retinal layers and fluid pathology, along with 3-D retinal profiling. CNN-STGS works by first extracting nine layers from an optical coherence tomography (OCT) scan. Afterward, the extracted layers, combined with a deep CNN model, are used to automatically segment cyst and serous pathology, followed by the autonomous 3-D retinal profiling. CNN-STGS has been validated on publicly available Duke datasets (containing a cumulative of 42,281 scans from 439 subjects) and Armed Forces Institute of Ophthalmology dataset (containing 4,260 OCT scans of 51 subjects), which are acquired through different OCT machinery. The performance of the CNN-STGS framework is validated through the marked annotations, and it significantly outperforms the existing solutions in various metrics. The proposed CNN-STGS framework achieved a mean Dice coefficient of 0.906 for segmenting retinal fluids, along with an accuracy of 98.75% for characterizing cyst and serous fluid from diseased retinal OCT scans.
关键词： convolutional neural network (CNN),Optical coherence tomography (OCT),maculopathy,ophthalmology,graph search
更新于2025-09-23 15:23:52
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OCT Angiography of the Choriocapillaris in Central Serous Chorioretinopathy: A Quantitative Subgroup Analysis
摘要： Introduction: To quantify optical coherence tomography angiography (OCTA) signal changes at the level of the choriocapillaris (CC) in patients with different stages of central serous chorioretinopathy (CSC) and to explore any correlation between subretinal fluid (SRF) and retinal pigment epithelium (RPE) alterations and the OCTA CC signal. Methods: One hundred one CSC eyes and 42 healthy control eyes were included in this retrospective study. CSC patients were allocated into four groups: acute, non-resolving, chronic atrophic and inactive CSC. CC OCTA images (AngioPlex?, Zeiss) were automatically quantified using an image-processing algorithm. Spatial correlation analysis of OCTA signals was performed by overlapping macular edema heatmaps and fundus autofluorescence images with corresponding OCTA images. Results: Active CSC subgroups demonstrated significantly more increased and decreased flow pixels in the CC compared with controls (p < 0.0001). No significant OCTA changes were seen within the active CSC groups or between the inactive and healthy subgroup. Spatial correlation analysis revealed a decreased OCTA signal in the SRF area and an increased signal outside the SRF area in acute CSC. Areas of RPE atrophy co-localized with areas of increased choriocapillaris OCTA signal, while areas with RPE alterations exhibited a normal signal compared with unaffected RPE. Conclusion: The decreased OCTA signal in the area of SRF in acute CSC could be evidence of localized CC hypoperfusion or due to shadowing artifacts. The missing CC OCTA changes in altered RPE adjacent to atrophy argues against CC injury. Studies with higher resolution and optimized image acquisition are warranted to further validate our findings.
关键词： Choriocapillaris,OCT angiography,Central serous chorioretinopathy
更新于2025-09-23 15:23:52
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Development of a new algorithm based on FDT Matrix perimetry and SD-OCT to improve early glaucoma detection in primary care
摘要： Purpose: The purpose of this study was to develop an objective algorithm to discriminate the earliest stages of glaucoma using frequency doubling technology (FDT) Matrix perimetry and spectral domain-optical coherence tomography (OCT) technology to improve primary care detection. Materials and methods: Three hundred six eyes (mean age 58.67±15.12) from 161 patients were included and classified in the following three groups: 101 nonglaucoma (GI-NG), 100 glaucoma suspect (GII-SG), and 105 open-angle glaucoma (GIII-OAG). All participants underwent a visual field exploration using the Humphrey Matrix visual field instrument and retinal nerve fiber layer evaluation using the Topcon 3D OCT-2000. Pattern deviation plot was divided into 19 areas and five aggrupation or quadrants and ranked with a value between 0 and 4 according to its likelihood of normality, and differences among three groups were analyzed. Principal component analysis (PCA) was also used to extract the most notable features of FDT and OCT, and a logistic regression analysis was applied to obtain the classification rules. Results: Only area numbers 7 and 12 and the central zone of FDT Matrix showed statistical differences (P<0.05) between GI-NG and GII-SG. The classification rules were estimated by the four PCA obtained from FDT Matrix and 3D OCT-2000 in a separate and combined use. Area under the receiver operating characteristic curve was 78.88% with FDT-PCA, 82.09% with OCT-PCA, and 94.27% with combined use of FDT and OCT-PCA to discriminate GI-NG and GII-SG. Conclusion: The predictive rules based on FDT-PCA or OCT-PCA provide a high sensitivity and specificity to detect the earliest stages of glaucoma and even better in combined use. These predictive rules may help the future development of software for FDT Matrix perimetry and 3D OCT-2000, which will greatly improve their diagnostic ability, making them useful in daily practice in a primary care setting.
关键词： 3D OCT-2000,PCA,glaucoma,primary care,FDT Matrix
更新于2025-09-23 15:23:52
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Scleral Thinning After Repeated Intravitreal Injections of Antivascular Endothelial Growth Factor Agents in the Same Quadrant
摘要： PURPOSE. We assessed the effects of intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy on scleral architecture using spectral domain anterior segment optical coherence tomography (OCT). METHODS. A total of 35 eyes of 35 patients treated with at least 30 intravitreal injections in one eye in the inferotemporal quadrant with ranibizumab or a?ibercept and 10 or less intravitreal injections in the fellow eye attending the intravitreal injection clinic were included. Enhanced depth imaging anterior segment OCT was used to measure scleral thickness. For each eye the sclera was measured in four quadrants at 3 mm from the limbus. In addition axial eye length was measured in all subjects using partial coherence interferometry. RESULTS. The mean number of intravitreal injections was 42 (range, 30–73) and 1.6 (range, 0–9) in the fellow eyes. In the study eyes with more than 30 injections the average scleral thickness in the inferotemporal quadrant was 568.4 lm (SD 6 66 lm) and 590.6 lm (SD 6 75 lm) in the fellow eyes with 10 or less injections (P ? 0.003). The mean average scleral thickness in the other three quadrants (inferonasal, superotemporal, and superonasal) was 536.6 lm in the study eyes (SD 6 100 lm) and 545.2 lm (SD 6 109 lm) in the fellow eyes (P ? 0.22). There was a borderline association of the total number of injections with scleral thickness change in the inferotemporal quadrant (r ? 0.3, P ? 0.052). CONCLUSIONS. Intravitreal injections may lead to scleral changes when applied repeatedly in the same quadrant. Thus, alternating the injection site should be considered in patients requiring multiple intravitreal injections.
关键词： retina,anterior segment OCT,anti-VEGF,intravitreal injections,sclera
更新于2025-09-23 15:23:52
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[Lecture Notes in Computer Science] Euro-Par 2018: Parallel Processing Workshops Volume 11339 (Euro-Par 2018 International Workshops, Turin, Italy, August 27-28, 2018, Revised Selected Papers) || Modeling and Optimizing Data Transfer in GPU-Accelerated Optical Coherence Tomography
摘要： Signal processing of optical coherence tomography (OCT) has become a bottleneck for using OCT in medical and industrial applications. Recently, GPUs gained more importance as compute device to achieve video frame rate of 25 frames/s. Therefore, we develop a CUDA implementation of an OCT signal processing chain: We focus on reformulating the signal processing algorithms in terms of high-performance libraries like CUBLAS and CUFFT. Additionally, we use NVIDIA’s stream concept to overlap computations and data transfers. Performance results are presented for two Pascal GPUs and validated with a derived performance model. The model gives an estimate for the overall execution time for the OCT signal processing chain, including compute and transfer times.
关键词： GPU,OCT,CUDA,Performance model
更新于2025-09-23 15:23:52
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Combined use of Doppler OCT and en Face OCT Functions for Discrimination of an Aneurysm in the Lamina Cribrosa from a Disc Hemorrhage
摘要： purpose: In addition to retinal nerve fiber layer thickness measurements, the recently introduced AngioVue optical coherence tomography (OCT) offers corresponding layer-by-layer Doppler OCT and en face OCT functions, for simultaneous evaluation of perfusion and structure of the optic nerve head. We investigated the clinical usefulness of combined use of Doppler and en face Fourier-domain OCT functions of the AngioVue Fourier-domain OCT for discrimination of a disc hemorrhage and a disc hemorrhage–like atypical vessel structure located deep in the lamina cribrosa. Case report: We present our findings with AngioVue OCT on a disc hemorrhage and a spatially related retinal nerve fiber layer bundle defect in a glaucomatous eye (case 1). Both alterations were detected on en face OCT images without any Doppler OCT signal. We also report on an aneurysm suggestive for a disc hemorrhage on clinical examination and disc photography in a treated ocular hypertensive eye (case 2). The aneurysm was within the lamina cribrosa tissue at the border of the cup and the neuroretinal rim. This vascular structure produced strong Doppler signals but no structurally detectable signs on the en face OCT images. Conclusions: Combined evaluation of corresponding Doppler OCT and en face OCT images enables ophthalmologists to easily separate true disc hemorrhages from disc hemorrhage–like deep vascular structures. This is of clinical significance in preventing unnecessary intensification of pressure-lowering treatment in glaucoma.
关键词： Doppler optical coherence tomography,Aneurysm,AngioVue OCT,Optic disc hemorrhage,En face Fourier-domain OCT,Glaucoma progression
更新于2025-09-23 15:22:29
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Comparison of choroidal thickness measurements between spectral-domain OCT and swept-source OCT in normal and diseased eyes
摘要： Purpose: Sub-foveal choroidal thickness (SFCT) is affected in many ocular diseases. The aim of this study was to compare SFCT measurements between Topcon 3D 2000 spectral-domain optical coherence tomography (SD-OCT) and Topcon swept-source OCT (SS-OCT), with different laser wavelengths, in normal and diseased populations. Materials and methods: This was a prospective, cross-sectional, noninterventional study including 27 normal volunteers and 27 participants with retinal disease. OCT scans were performed sequentially and under standardized conditions using both SD-OCT and SS-OCT. The OCT scans were evaluated by two independent graders. Paired t-tests and intraclass correlation coefficients (ICCs) were used to assess the statistically significant difference between SFCT measurements as measured by the two devices. Results: Mean SFCT measurements for all 54 participants were 264.9±103.1 μm using SD-OCT (range: 47–470 μm) and 278.5±110.5 μm using SS-OCT (range: 56–502 μm), with an inter-device ICC of 0.850. Greater variability was noted in the diseased eyes. Inter-device ICCs were 0.870 (95% CI; 0.760–0.924) and 0.840 (95% CI; 0.654–0.930) for normal and diseased eyes, respectively. However, the difference was not statistically significant (P=0.132). Conclusion: Both machines reliably measure SFCT. Larger studies are needed to confirm these findings.
关键词： SD-OCT,normal,choroidal imaging,diseased,SS-OCT
更新于2025-09-23 15:22:29
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Repeatability and reproducibility of retinal nerve fibre layer thickness measurements with the iVue-100 optical coherence tomographer
摘要： Background: Accurate and repeatable measurements of the retinal nerve fibre layer (RNFL) thickness are important in the diagnosis and management of glaucoma and other disorders. Objective: To assess the repeatability and reproducibility of the iVue-100 optical coherence tomographer (OCT). Methods: The thickness of the RNFL was measured for 50 healthy participants using the iVue-100 OCT. Although both eyes per participant were measured, only right eyes were analysed here. Repeatability and reproducibility of the iVue-100 OCT were assessed using the intraclass correlation coefficient (ICC), coefficient of variation (CoV), paired t-tests and Bland-Altman analysis. Results: Good intra-observer repeatability was obtained as indicated by the ICC of observer 1 (range: 0.941 - 0.976) and observer 2 (range: 0.829 – 0.953) as well by the CoV of observer 1 (range: 0.098 – 0.137) and observer 2 (0.091 – 0.132). In terms of inter-observer reproducibility, significant differences (p< 0.05) in mean measurements between the observers were noted for the average RNFL readings and in the superior and inferior quadrants as assessed with paired t-tests. Even though significant inter-session differences were found for the average RNFL thickness and the superior quadrant (p = 0.003 and p = 0.013, respectively), excellent ICCs were obtained for inter-session reproducibility (range: 0.914 – 0.979). Conclusion: The iVue-100 OCT demonstrated good repeatability and reproducibility for RNFL thickness measurements.
关键词： Retinal nerve fibre layer thickness,optical coherence tomography,repeatability,iVue-100 OCT,reproducibility
更新于2025-09-23 15:22:29
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Reproducibility of Macular Vessel Density Calculations Via Imaging With Two Different Swept-Source Optical Coherence Tomography Angiography Systems
摘要： Purpose: To evaluate the reproducibility of vessel density calculations using different binarization methods obtained via two commercially available swept-source optical coherence tomography angiography (SS-OCTA) systems. Methods: Healthy volunteers were imaged using two swept-source optical coherence tomography angiography (SS-OCTA) devices, PLEXElite and Triton. SS-OCTA examinations were performed using a 3 3 3-mm volume scan pattern centered on the fovea. A total of six methods were used for binarization in ImageJ, two global thresholding and four local adaptive thresholding methods. Resultant vessel density values were compared between the instruments and binarization methods. Images for 60 eyes from 30 healthy subjects were assessed by two reviewers who were blinded to the scanning system used. Results: Twenty-two eyes were excluded due to poor image quality (17 eyes from Triton, 4 eyes from PLEXElite, and 1 eye from both instruments, P ? 0.003). A final 38 eyes from 23 subjects were eligible for analysis. Each binarization method and instrument led to different median values. The coefficients of variation for vessel density measurements ranged from 0.3% to 2.3% and 0.6% to 4.7% for the PLEXElite and Triton, respectively. Local adaptive thresholding methods revealed higher reproducibility than did global thresholding methods for both devices. Conclusions: Macular scans with both SS-OCTA instruments showed good reproducibility for vessel density measurements. PLEXElite recorded fewer poor images and had higher reproducibility than did Triton. These findings will inform the selection of proper binarization methods for the clinical detection of vascular diseases affecting the central retina.
关键词： superficial capillary plexus,vessel density,reproducibility,OCT angiography
更新于2025-09-23 15:22:29