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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
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Shearlet-Based Feature Extraction for the Detection and Classification of Age-Related Macular Degeneration in Spectral Domain Optical Coherence Tomography Images
摘要： Age-related macular degeneration (AMD) is an eye disease that usually affects central vision in people older than 50 years owing to accumulation of fluid in the macular region of the retina. Optical coherence tomography (OCT) is an imaging modality that is being widely used nowadays for the detection of abnormalities in the eye. In this work, a shearlet transformYbased method is proposed for automated detection of AMD. The 2-dimensional horizontal slices of spectral domain OCT imaging data are used as input images. Images are first converted to gray scale and denoised using bilateral filter. Denoised images are decomposed by applying shearlet transform and 10 textural features are extracted from the cooccurrence matrices of high-frequency transform coefficients. Based on these features, the OCT images are classified as normal or AMD using support vector machine and k-nearest neighbor classifiers. Results obtained using shearlet-based features are compared with that of wavelet transformYbased features. Best results are obtained when shearlet-based features are classified using support vector machine.
关键词： Shearlet transform,Wavelet transform,Support vector machine,Optical coherence tomography,K-nearest neighbor,Age-related macular degeneration
更新于2025-09-09 09:28:46
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In Vivo Quantification of Retinal Changes Associated With Drusen in Age-Related Macular Degeneration
摘要： PURPOSE. Drusen alters retinal architecture in early age-related macular degeneration (AMD). However, abnormalities also may exist in drusen-free areas of the AMD retina. This study examines retinal thickness above drusen relative to drusen-free areas in the same patient and a normal population. METHODS. Patients with early to intermediate AMD (n ? 122) or no disease (n ? 30) were examined at the Center for Eye Health. Spectral domain optical coherence tomography (SD-OCT) scans through single, isolated druse (n ? 125) or con?uent drusen (n ? 54) were obtained. The thickness of individual retinal layers was measured above the druse and in a drusen-free area, 150 lm from the drusen edge. RESULTS. Intraeye comparisons found total retinal thickness above drusen was 16 6 0.6% less than drusen-free areas. Thinning was mostly in the retinal pigment epithelium/photoreceptor layer (32 6 1% reduction) and the outer nuclear layer (22 6 1% reduction). Con?uent drusen showed similar thinning of the outer retina as well as inner retina loss (5%). Thinning was strongly correlated with drusen height, but only modestly correlated with drusen width. When compared to the normal population, retinal thickness above drusen and drusen-free areas were signi?cantly reduced. CONCLUSIONS. We con?rm outer retina thinning above drusen in early/intermediate AMD compared to drusen-free areas in the same retina or a normal population. Interestingly, drusen-free areas in AMD patients were not the same as control patients suggesting ‘‘normal’’ areas of the AMD retina are abnormal. The strong correlation between retinal thinning and drusen height, rather than width, suggests current grading systems for AMD may need re?nement.
关键词： drusen,age-related macular degeneration,optical coherence tomography,retinal thickness
更新于2025-09-09 09:28:46
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Phenotype Characteristics of Fellow Eyes in Patients With Early Onset of Neovascular Age-Related Macular Degeneration
摘要： PURPOSE. To investigate phenotype characteristics of fellow eyes in patients with early onset of neovascular age-related macular degeneration (NVAMD). METHODS. Patients with new-onset unilateral NVAMD between 50 and 65 years (n ? 57, early-onset choroidal neovascularization [CNV] group) or >80 years (n ? 47, late-onset CNV group) or with nonneovascular AMD (n ? 98, no-CNV group) were included. Fellow eyes in both CNV groups and the eyes with the more severe AMD staging in the no-CNV group were used to evaluate number and size of macular drusen, extramacular drusen (EMD), pigmentary abnormalities, and retinal pigment epithelium (RPE) atrophy on color photographs and hyperre?ective dots (HRD) and reticular pseudodrusen (RPD) on spectral-domain optical coherence tomography (SDOCT) scans. Regression analysis was used to compare groups. RESULTS. Occurrence of >20 macular drusen was more frequent in the early-onset CNV group than the late-onset CNV group (odds ratio [OR] 2.93; P ? 0.01) or the no-CNV group (OR 2.17; P ? 0.02). Retinal pigment epithelium atrophy, RPD, and HRD appeared less frequently in the early-onset CNV group than in the late-onset CNV group (RPE atrophy: OR 0.11; P ? 0.005; RPD: OR 0.04; P ? 9.38 3 10(cid:2)10, HRD: OR 0.30; P ? 0.004) and no-CNV group (RPE atrophy: OR 0.12; P ? 0.005; RPD: OR 0.40, P ? 0.03, HRD: not signi?cant). No differences were detected regarding presence of large drusen, pigmentary abnormalities, and EMD. CONCLUSIONS. A large number of macular drusen in the fellow eye appeared to be characteristic for early onset of NVAMD, whereas RPE atrophy, HRD, and RPD were more frequently present in AMD patients > 80 years. Prospective trials with patients converting to NVAMD are required to further analyze morphologic characteristics for early versus late development of advanced AMD.
关键词： reticular pseudodrusen,fellow eye,spectral-domain optical coherence tomography,neovascular age-related macular degeneration
更新于2025-09-09 09:28:46
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A single-arm, investigator-initiated study of the efficacy, safety, and tolerability of intravitreal aflibercept injection in subjects with exudative age-related macular degeneration previously treated with ranibizumab or bevacizumab (ASSESS study): 12-month analysis
摘要： In subjects with active exudative age-related macular degeneration, treating with a fixed intravitreal aflibercept injection dosing regimen for 12 months demonstrated improved anatomic and vision endpoints from baseline. Purpose: Switching therapies in neovascular age-related macular degeneration (AMD) may offer an advantage for some patients. This study evaluates the efficacy of intravitreal aflibercept injection (IAI) in subjects previously treated with ranibizumab and/or bevacizumab. Methods: Subjects (n=26) were given monthly 2 mg of IAI for 3 months, followed by 2 mg once in every 2 months for up to 12 months. The mean absolute change from baseline in central subfield thickness (CST) measured by optical coherence tomography and the mean change from baseline in best-corrected visual acuity (BCVA) early treatment in diabetic retinopathy study (ETDRS) letter score were obtained. Additionally, the percentage of subjects who gained or lost $15 letters of vision and the percentage of subjects who are 20/40 or better or 20/200 or worse were evaluated. Results: There was a mean decrease in CST of ?50.3 μm (P,0.001) and a mean increase in ETDRS BCVA of +9.2 letters (P,0.001). Twenty-seven percent of subjects experienced a $15-letter improvement in visual acuity, and no subject lost $3 lines of vision from baseline. Fifty percent of subjects were 20/40 or better, and 11.5% of subjects were 20/200 or worse at month 12. Conclusion: Fixed IAI dosing regimen for 12 months demonstrated improved anatomic and vision endpoints in subjects with active exudative AMD.
关键词： bevacizumab,aflibercept,vascular endothelial growth factors,ranibizumab,age-related macular degeneration
更新于2025-09-09 09:28:46
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Retinal metabolic and structural alterations in response to aflibercept treatment in neovascular age‐related macular degeneration
摘要： Purpose: Non-invasive retinal markers of disease activity could pave the way for individualized treatment in neovascular age-related macular degeneration (nAMD). We aimed to evaluate if retinal vascular oxygen saturation and calibres could predict the initial treatment response after a loading phase of intravitreal a?ibercept in nAMD. Method: A total of 149 eyes were included (nAMD, n = 76; dry AMD, n = 30; normal eyes n = 43). Of these, 57 treatment-na€?ve eyes with nAMD received three monthly injections with 2.0 mg a?ibercept and were subsequently strati?ed according to functional and structural response according to development in best-corrected visual acuity and macular retinal thickness. The retinal vascular oxygen saturation and calibres were measured prior to treatment and 1 month after the third injection. Results: Patients with nAMD and dry AMD had higher retinal arteriolar oxygen saturation as compared to normal eyes (94.3% versus 95.2% versus 92.6%, p = 0.04). Thirty-nine (68.4%) and 12 (21.1%) eyes with nAMD were functional and structural responders. After the loading phase, structural nonresponders developed a higher retinal arteriolar (95.3% versus 93.3%, p = 0.03) and venular (64.7% versus 59.4%, p = 0.02) oxygen saturation, and responders developed a lower retinal arteriolar calibre (118.0 versus 114.3 lm, p < 0.01). In a multiple logistic regression model, increasing retinal venular oxygen saturation associated with a negative structural treatment outcome (odds ratio 1.17 for each 1% increment after the loading phase, 95% con?dence interval 1.01–1.36, p = 0.03). Conclusion: Changes in the retinal venular oxygen saturation associate independently with initial treatment response in nAMD, but functional and structural retinal measurements prior to treatment could not predict the treatment response.
关键词： a?ibercept,retinal vascular calibre,disease activity,neovascular age-related macular degeneration,retinal oximetry,choroidal neovascularization
更新于2025-09-09 09:28:46
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Targeting modifiable risk factors in age-related macular degeneration in optometric practice in Sweden
摘要： The purpose of this study was to investigate the extent to which ophthalmologists and optometrists in Sweden recommend the use of nutritional supplements, changes in diet, or smoking cessation to patients who are at risk of or with signs of age-related macular degeneration (AMD). In addition, this study also examined how these practitioners rate the strength of evidence for nutritional supplements in AMD management and which sources of information they consult to determine supplement recommendations for the prevention or treatment of AMD. Methods: This study implemented a cross-sectional design using data from a questionnaire. All Swedish optometrists and ophthalmologists who were registered in the membership databases of their respective professional organizations were invited to participate. The questionnaire contained 18 forced choice questions and one free text question and was organized into the following four sections: use of nutritional supplements, dietary advice, smoking and eye diseases, and strength of evidence and the sources of information regarding nutritional supplement interventions. Results: The response rate was 40.3% for optometrists and 5% for ophthalmologists. Optometrists were more likely than ophthalmologists to recommend nutritional supplements in AMD and provided significantly more advice about diet than did the ophthalmologists for both patients at risk for AMD and those with established disease. The ophthalmologists were more likely than the optometrists to rely on the findings from the age-related eye disease studies of AMD regarding treatment with and selection of supplements and to recommend smoking cessation. Conclusion: Common evidence-based strategies for AMD management among eye care professionals would presumably be beneficial for AMD patients. Targeted education and implementation strategies may be needed.
关键词： diet,nutritional supplements,smoking,age-related macular degeneration
更新于2025-09-04 15:30:14