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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Automatic Detection of Preferred Retinal Locus (PRL) for Low Vision Rehabilitation using Oculometrics Analysis*
摘要： Low vision rehabilitation is an important step towards individuals with Age-related macular degeneration (AMD) regaining useful functional vision and quality of life. One of the key steps in low vision rehabilitation is the determination of the preferred retinal locus (PRL). Currently, localization of PRL is performed manually though the guidance of a low vision therapist and the process is highly time-consuming, labour-intensive and subjective. In this paper, we present an automated system to objectively and accurately locate an individual’s PRL with the aid of gaze tracking technology. We also propose a graph-based method for false fixation detection to improve the system robustness. We validated the reliability of the system by using eye tracking technology to simulate central vision loss on people with normal vision. Experimental results show the potential use of eye tracking in detecting PRL for low vision rehabilitation.
关键词： Preferred retinal locus,Eye tracking technology,Low vision rehabilitation,False fixation detection,Age-related macular degeneration
更新于2025-09-10 09:29:36
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Initial Utilization of Aflibercept in Exudative Age-related Macular Degeneration
摘要： Purpose: Intravitreal aflibercept, a fusion protein with high affinity for vascular endothelial growth factor, offers an alternative treatment for exudative age-related macular degeneration. Preclinical studies and early and late phase clinical trials suggest that aflibercept’s high binding affinity may impart greater durability of activity and increased efficacy compared to ranibizumab or bevacizumab. Methods: A total of 266 eyes of 249 patients with exudative age-related macular degeneration who received aflibercept after treatment with bevacizumab and/or ranibizumab were included in a retrospective review. Mean central subfoveal thickness on spectral-domain optical coherence tomography and mean logarithm of the minimal angle of resolution (logMAR) visual acuity were calculated at 1, 3, 6, and 12 months after the first aflibercept injection. Subgroup analyses were performed in eyes receiving at least 5 bevacizumab and/or ranibizumab injections in the 6 months prior to aflibercept and in eyes receiving at least 10 injections in the 12 months prior to aflibercept. Results: Eyes received an average of 14.7 (range 1-43) ranibizumab and/or bevacizumab treatments prior to initiation of aflibercept therapy. The mean central subfoveal thickness decreased from 300 to 275 μm at 1 month (p<0.001) and was maintained at 6 months. Mean logMAR visual acuity improved from 0.60 (Snellen equivalent 20/80) to 0.54 (20/70, p = 0.01) at 1 month and was stable at 0.55 at 6 months (Snellen equivalent 20/70, p = 0.11, n = 251). In 82 eyes receiving at least 5 injections in the 6 months prior to aflibercept treatment (average of 18.1 injections total), the central subfoveal thickness improved from 296 to 279 μm at 1 month (p<0.0001) and was maintained at 6 months (p<0.0001). Visual acuity did not change (0.48 [20/61] at 1 month compared to baseline, 0.49 [20/62], p = 0.634, and at 6 months 0.51 [20/65], p = 0.601). In 50 eyes receiving at least 10 injections in the 12 months prior to aflibercept treatment (average of 21.8 injections total), the mean central subfoveal thickness decreased by 17 μm at 1 month (p = 0.0007) and was maintained at 6 months (p = 0.013). Again, visual acuity did not change (0.46 [20/56] at 1 month, baseline 0.44 [20/56], p = 0.547, and 0.50 [20/63] at 6 months, p = 0.2445). Conclusions: Aflibercept is a valuable treatment alternative in patients previously treated with bevacizumab and/or ranibizumab injections. Stability of visual acuity and anatomic improvement on spectral-domain optical coherence tomography were observed after initiation of aflibercept treatment in those previously treated with ranibizumab and/or bevacizumab injections every 4-6 weeks.
关键词： Ranibizumab,Age-related macular degeneration,Choroidal neovascularization,Aflibercept,Bevacizumab
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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Optical coherence tomography angiography in exudative age-related macular degeneration: a predictive model for treatment decisions
摘要： Aims To evaluate on optical coherence tomography angiography (OCT-A), the predictive role of different qualitative findings of choroidal neovascularisations (CNV) in assessing the status of exudative age-related macular degeneration (eAMD) and to develop a potential model to predict the CNV activity. Methods Retrospective review of the multimodal imaging records of patients with eAMD obtained during treatment for type 1 or type 2 CNV. The qualitative analysis of CNVs on OCT angiograms assessed the presence or absence of tiny branching vessels, loops, peripheral anastomotic arcades and choriocapillaris hypointense halo. These findings were then correlated with those of structural OCT scans. A score forecast was built and validated. results One hundred and twenty-six eAMD eyes were enrolled in the study. Exudation was observed in 90 eyes (71%) on structural OCT. The qualitative OCT-A analysis revealed: tiny branching vessels in 82.5% of the cases, vascular loops in 81.7%, peripheral anastomotic arcades in 66.7% and choriocapillaris hypointense halo in 54.8%. In the univariate analysis, each OCT-A parameter showed a statistically significant correlation with exudation on structural OCT (p<0.001). The overall analysis demonstrated a sensitivity of 96.7% and a positive predictive value of 87.9%. In the multivariate analysis, a model with four criteria predicted an exudative lesion in 97.6% of cases and one with two criteria (tiny branching vessels and peripheral anastomotic arcades) in 71.2%. Conclusions The presence of tiny branching vessels and a peripheral anastomotic arcade appears to predict the lesion activity with a good accuracy and the model based on four criteria enables optimal decisions regarding retreatment in eAMD.
关键词： exudative age-related macular degeneration,optical coherence tomography angiography,treatment decisions,choroidal neovascularisations,predictive model
更新于2025-09-10 09:29:36
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Macular Atrophy Development and Subretinal Drusenoid Deposits in Anti-Vascular Endothelial Growth Factor Treated Age-Related Macular Degeneration
摘要： PURPOSE. To explore the association between presence of subretinal drusenoid deposits (SDD) at baseline in eyes with neovascular age-related macular degeneration (nAMD) with the development of macular atrophy (MA) during anti-vascular endothelial growth factor (VEGF) therapy. METHODS. There were 74 eyes without pre-existing MA receiving anti-VEGF therapy for nAMD for 2 years or longer analyzed. At least two image modalities that included spectral-domain optical coherence tomography, near-infrared re?ectance, ?uorescein angiography, and color fundus photos were used to assess for SDD presence, phenotype (dot and ribbon), and location, neovascularization type, and MA. Logistic regression models using generalized estimating equations assessed the association between SDD and the development of MA adjusting for age, neovascularization type, and choroidal thickness. RESULTS. SDD were present in 46 eyes (63%) at baseline. MA developed in 38 eyes (51%) during the mean of 4.7 6 1.2 years of follow-up. Compared with eyes without SDD, those with SDD at baseline were 3.0 times (95% con?dence interval [CI] 1.1–8.5, P ? 0.0343) more likely to develop MA. Eyes with SDD present in the inferior macula and inferior extramacular ?elds at baseline were 3.0 times and 6.5 times more likely to develop MA at follow-up than eyes without SDD in these locations (95% CI 1.0–8.9, P ? 0.0461 and 95% CI 1.3–32.4, P ? 0.0218, respectively). MA development was not associated with a speci?c SDD phenotype. CONCLUSIONS. MA frequently developed in eyes during anti-VEGF treatment. SDD were independently associated with MA development. The extension of SDD into the inferior fundus, particularly in the inferior extramacular ?eld, conferred higher odds of subsequent MA development.
关键词： reticular pseudodrusen,anti-VEGF,neovascular age-related macular degeneration,geographic atrophy,subretinal drusenoid deposits
更新于2025-09-10 09:29:36
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Spatial Correspondence Between Intraretinal Fluid, Subretinal Fluid, and Pigment Epithelial Detachment in Neovascular Age-Related Macular Degeneration
摘要： PURPOSE. To identify the spatial distribution of exudative features of choroidal neovascularization in neovascular age-related macular degeneration (nAMD) based on the localization of intraretinal cystoid fluid (IRC), subretinal fluid (SRF), and pigment-epithelial detachment (PED). METHODS. This retrospective cross-sectional study included spectral-domain optical coherence tomography volume scans (6 3 6 mm) of 1341 patients with treatment-na¨?ve nAMD. IRC, SRF, and PED were detected on a per-voxel basis using fully automated segmentation algorithms. Two subsets of 37 volumes each were manually segmented to validate the automated results. The spatial correspondence of components was quantified by computing proportions of IRC-, SRF-, or PED-presenting A-scans simultaneously affected by the respective other pathomorphologic components on a per-patient basis. The median across the population is reported. Odds ratios between pairs of lesions were calculated and tested for significance pixel wise. RESULTS. Automated image segmentation was successful in 1182 optical coherence tomography volumes, yielding more than 61 million A-scans for analysis. Overall, 81% of eyes showed IRC, 95% showed SRF, and 92% showed PED. IRC-presenting A-scans also showed SRF in a median 2.5%, PED in 32.9%. Of the SRF-presenting A-scans, 0.3% demonstrated IRC, 1.4% PED. Of the PED-presenting A-scans, 5.2% contained IRC, 2.0% SRF. Similar patterns were observed in the manually segmented subsets and via pixel-wise odds ratio analysis. CONCLUSIONS. Automated analyses of large-scale datasets in a cross-sectional study of 1182 patients with active treatment-na¨?ve nAMD demonstrated low spatial correlation of SRF with IRC and PED in contrast to increased colocalization of IRC and PED. These morphological associations may contribute to our understanding of functional deficits in nAMD.
关键词： subretinal fluid,age-related macular degeneration,intraretinal cystoid fluid,optical coherence tomography,automated image analysis
更新于2025-09-10 09:29:36
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Changes in Fixation Stability with Time during Binocular and Monocular Viewing in Maculopathy
摘要： The purpose of this study was to examine changes in ?xation stability over time during binocular and monocular viewing in patients with age-related macular degeneration (AMD). Seventeen patients with AMD and 17 controls were enrolled. Using an EyeLink eyetracker (SR Research Ltd., Mississauga, Ontario, Canada), ?xation stability was recorded binocularly and monocularly with each eye for a duration of 15 s while the fellow eye was covered. Fixation stability was analyzed over 3 s intervals for each condition using a 68% bivariate contour ellipse area. Fixation stability did not change with time during binocular viewing for both groups, both monocular conditions for the control group, and monocular viewing with the better eye for the AMD group. However, during monocular viewing with the worse eye, the test of within-subject contrasts showed linear improvement in ?xation stability with time (p = 0.016). In conclusion, in patients with AMD, monocular ?xational control with the worse eye is poor, but improves with time.
关键词： ?xation duration,worse eye,age-related macular degeneration,?xation stability,preferred retinal locus,central vision loss
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE 20th International Conference on e-Health Networking, Applications and Services (Healthcom) - Ostrava, Czech Republic (2018.9.17-2018.9.20)] 2018 IEEE 20th International Conference on e-Health Networking, Applications and Services (Healthcom) - Extraction and Analysis of RPE layer from OCT Images for Detection of Age Related Macular Degeneration
摘要： Age-related Macular Degeneration (AMD) is an eye disease which affects elderly people. Cholesterol deposits in central part of retina, known as macula, damages the photoreceptors present in a particular area of eye. AMD usually effects only central vision of patient. In medical field various imaging techniques are used for diagnosis of eye diseases. Optical Coherence Tomography (OCT) is a relatively newer technique that is found to be very useful in analyzing eyes. In this research, we used OCT images to automatically detect and classify AMD. First we extract the retinal layer known as Retinal Pigment Epithelium by utilizing Graph Theory Dynamic Programming technique, after successfully enhancing the quality of OCT image by using Wiener filter. We used a unique feature set consisting of features extracted from difference signal of RPE and Inner Segment Outer Segment layer of RPE. Feature set includes approximation coefficient, entropy and spectrum energy of the resulting difference signal. Support Vector Machine classifier was used to classify AMD affected and normal image. The developed system gives an accuracy of 95% for AMD detection.
关键词： Optical Coherence Tomography,Age-Related Macular Degeneration,Computer Aided Diagnostic
更新于2025-09-10 09:29:36
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Assessing the Anatomical and Functional Efficacy of Aflibercept on Wet ARMD: An OCT and Mferg Recording
摘要： Objective: To investigate the therapeutic efficacy of aflibercept on sub-foveal choroidal neovascularization due to Age-Related Macular Degeneration (ARMD). Methods: Fifteen patients (15 eyes) with sub-foveal choroidal neovascularization due to ARMD were treated with intravitreal aflibercept. The doses were monthly for the first three months, being repeated every three months after for one year, using 2 mg of intravitreal aflibercept. A total of six aflibercept injections were, finally, performed during the 12-month study. All patients underwent a complete ophthalmic examination, including the measurement of best-corrected visual acuity, fundus examination, intraocular pressure measurement, fluorescein angiography, optical coherence tomography (OCT) scan and multifocal electroretinography (mfERG) recording, at the baseline and at the first, second, third, sixth, ninth and 12th month after the first injection of aflibercept. Two masked examiners evaluated the visual acuity based on standard Snellen charts. Results: Fifteen patients (15 eyes), of mean age 69.2 ± 4.9 years old, with sub-foveal choroidal neovascularization due to ARMD were participated in this study. The mean BCVA was 0.12 ± 0.08, 0.20 ± 0.10, 0.25 ± 0.1, 0.28 ± 0.1, 0.34 ± 0.14, 0.36 ± 0.14 and 0.40 ± 0.14 decimal, at presentation, 1st, 2nd, 3rd, 6th, 9th and 12th month, respectively. Significant differences in amplitudes but not in latencies of three rings were observed over time. Significant reductions were noted among the central retinal thickness measurements before intravitreal aflibercept and at 1st, 2nd, 3rd, 6th, 9th and 12th month (465.0 ± 161.4, 374.9 ± 139.5, 323.3 ± 113.8, 290.3 ± 85, 263.3 ± 69, 243.0 ± 60.6 and 226.9 ± 63.5, respectively). Conclusion: This is the first time that anatomical and functional improvement of the macula in patients with sub-foveal choroidal neovascularization due to ARMD was shown objectively, based on OCT and mfERG recordings. In addition, the improvement of visual acuity was noted over time. Our study supports the fact that intravitreal use of aflibercept is safe and effective in treating sub-foveal choroidal neovascularization observed in patients with ARMD.
关键词： findings,electroretinography,Macular,Aflibercept,Anatomical,Sub-foveal,Multifocal,Optical coherence tomography,choroidal neovascularization,Function,Age-related macular degeneration
更新于2025-09-09 09:28:46
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The potent small molecule integrin antagonist THR-687 is a promising next-generation therapy for retinal vascular disorders
摘要： Integrins are associated with various eye diseases such as diabetic retinopathy (DR) and wet age-related macular degeneration (AMD) and implicated in main pathologic disease hallmarks like neovascularization, inflammation, fibrosis and vascular leakage. Targeting integrins has the potential to attenuate these vision-threatening processes, independent of anti-vascular endothelial growth factor (VEGF) responsiveness. The current investigation characterized THR-687 as a novel pan RGD (arginylglycylaspartic acid) integrin receptor antagonist able to compete for binding with the natural ligand with nanomolar potency (e.g. αvβ3 (IC50 of 4.4±2.7 nM), αvβ5 (IC50 of 1.3±0.5 nM) and α5β1 (IC50 of 6.8±3.2 nM). THR-687 prevented the migration of human umbilical vein endothelial cells (HUVECs) into a cell-free area (IC50 of 258±113 nM) as well as vessel sprouting in an ex vivo mouse choroidal explant model (IC50 of 236±173 nM), and was able to induce the regression of pre-existing vascular sprouts. Moreover, combined intravitreal and intraperitoneal administration of THR-687 potently inhibited VEGF-induced leakage in the mouse retina. In addition, THR-687 injected intravitreally at 3 different dose levels (0.45 mg, 2.25 mg or 4.5 mg/eye) potently inhibited neovascularization-induced leakage in the cynomolgus laser-induced choroidal neovascularization (CNV) model. These data suggest that THR-687 is a promising drug candidate for the treatment of vision-threatening retinal vascular eye diseases such as DR and wet AMD.
关键词： diabetic retinopathy,retinal vascular disorders,angiogenesis,THR-687,Integrin antagonist,wet age-related macular degeneration,vascular leakage
更新于2025-09-09 09:28:46