VEA: Vessel Extraction Algorithm by Active Contour Model and a Novel Wavelet Analyzer for Diabetic Retinopathy Detection

2018 ◽  
Vol 18 (02) ◽  
pp. 1850008 ◽  
Author(s):  
Swarup Kr Ghosh ◽  
Anupam Ghosh ◽  
Amlan Chakrabarti

The process of retinal vessel segmentation is important for detection of various eye conditions including the effect of diabetes on eyes, or diabetic retinopathy. As we know, the retinal microvasculature is unique since it is the only part of the human circulation system that can be directly and non-evasively visualized in vivo; readily photographed as well as subjected to digital image analysis. This paper explores a new technique for detecting the idiosyncrasies of retina images, for which we have reviewed some well-known image segmentation algorithms that help in detecting retinal abnormalities. In this work, we have also focused on the extraction of the vessel from retina images and developed an automated diagnostic system for diabetic retinopathy. This paper represents techniques, such as the snake model that was used for auto-extraction of retinal blood vessels and use of wavelet decomposition and back propagation neural network to extract the retinal vessels features and analyze the dataset. Finally, an analysis of performance of the vessel segmentation algorithm and wavelet analysis on standard image databases has been done. In this context, we have used F-score for validation of the result.

2020 ◽  
Vol 8 (6) ◽  
pp. 4210-4215

Aim: To design diagnostic expert system using fuzzy image processing for diabetic retinopathy, measures diabetic eye morbidity. Method: From this research paper, diagnosing diabetic retinopathy using fuzzy image processing for diabetic patients. Firstly collection of OCT images of the patient who has diabetic retinopathy. Author’s proposed method finds out the edge detection of the OCT image. Then fuzzy logic is applied on that result of image processing. Design a fuzzy rules and input- output parameter. This method gives accurate diagnosing the diabetic retinopathy from the image of the patient’s retina images. Result: This diagnostic system gives patient’s eye morbidity, vision threatening of the diabetic patients. In the result, edges of the retina images, and from that retinal ruptures, thickness of the proliferative in the retina. From these result, diagnostic of diabetic retinopathy conditions such as PDR, NPDR, and NORMAL, and CSME in the diabetic patients. Conclusion: author has design diagnostic system for endocrinologist and ophthalmology to diagnosed diabetic retinopathy in the patients. From this system doctors don’t need patients for diagnosing purposed.


2020 ◽  
Author(s):  
Ada Admin ◽  
Bruce A. Corliss ◽  
H. Clifton Ray ◽  
Richard W. Doty ◽  
Corbin Mathews ◽  
...  

Diabetic retinopathy is a potentially blinding eye disease that threatens the vision of a ninth of diabetic patients. Progression of the disease has long been attributed to an initial dropout of pericytes that enwrap the retinal microvasculature. Revealed through retinal vascular digests, a subsequent increase in basement membrane bridges is observed. Using cell-specific markers, we demonstrate that pericytes rather than endothelial cells colocalize with these bridges. We show that the density of bridges transiently increases with elevation of Ang-2, PDGF-BB, and blood sugar, is rapidly reversed on a time scale of days, and often associated with a pericyte cell body located off-vessel. Cell-specific knockout of KLF4 in pericytes fully replicates this phenotype. <i>In vivo</i> imaging of limbal vessels demonstrates pericyte migration off-vessel, with rapid pericyte filopodial-like process formation between adjacent vessels. Accounting for off-vessel and on-vessel pericytes, we observe no pericyte loss relative to non-diabetic control retina. These findings reveal the possibility that pericyte perturbations in location and process formation may play a role in the development of pathological vascular remodeling in diabetic retinopathy.


2020 ◽  
Author(s):  
Ada Admin ◽  
Bruce A. Corliss ◽  
H. Clifton Ray ◽  
Richard W. Doty ◽  
Corbin Mathews ◽  
...  

Diabetic retinopathy is a potentially blinding eye disease that threatens the vision of a ninth of diabetic patients. Progression of the disease has long been attributed to an initial dropout of pericytes that enwrap the retinal microvasculature. Revealed through retinal vascular digests, a subsequent increase in basement membrane bridges is observed. Using cell-specific markers, we demonstrate that pericytes rather than endothelial cells colocalize with these bridges. We show that the density of bridges transiently increases with elevation of Ang-2, PDGF-BB, and blood sugar, is rapidly reversed on a time scale of days, and often associated with a pericyte cell body located off-vessel. Cell-specific knockout of KLF4 in pericytes fully replicates this phenotype. <i>In vivo</i> imaging of limbal vessels demonstrates pericyte migration off-vessel, with rapid pericyte filopodial-like process formation between adjacent vessels. Accounting for off-vessel and on-vessel pericytes, we observe no pericyte loss relative to non-diabetic control retina. These findings reveal the possibility that pericyte perturbations in location and process formation may play a role in the development of pathological vascular remodeling in diabetic retinopathy.


2021 ◽  
Vol 9 (1) ◽  
pp. e002327
Author(s):  
Zhiping Liu ◽  
Hong Jiang ◽  
Justin H Townsend ◽  
Jianhua Wang

IntroductionTo evaluate effects of Ocufolin on retinal microvasculature in mild non-proliferative diabetic retinopathy patients who carried methylenetetrahydrofolate reductase (MTHFR) polymorphisms (DR+MTHFRP).Research design and methodsThis is a prospective cohort study. Eight DR+MTHFRP (administrated Ocufolin for 6 months) and 15 normal controls (NCs) were recruited. MTHFR polymorphisms were subtyped as normal, C677T, or A1298C. Best-corrected visual acuity (BCVA) was evaluated. Retinal vessel density (VD) and microstructure were evaluated by optical coherence tomography angiography.ResultsBCVA and vascular indices of DR+MTHFRP at baseline were worse than those of NC and improved. Compared with baseline, DR+MTHFRP had significantly improved BCVA during follow-up period (p<0.05). VD of superficial vascular plexus was increased at 4 months (p=0.012), while VD of retinal vascular network did not change (p>0.05). Carriers of A1298C and C677T showed statistically significant increase in VD at all layers by 6 months, while carriers of C677T alone showed no significant change and carriers of A1298C alone showed decreased density from 4 months to 6 months. Microstructure did not change during the follow-up period.ConclusionA 6-month intake of Ocufolin is capable of reversing structural changes of microangiopathy in mild non-proliferative DR+MTHFRP. This suggests a novel way to address these impairments prior to catastrophic vision loss.


2020 ◽  
Vol 37 ◽  
Author(s):  
Bruce A. Berkowitz

Abstract Patients with diabetes continue to suffer from impaired visual performance before the appearance of overt damage to the retinal microvasculature and later sight-threatening complications. This diabetic retinopathy (DR) has long been thought to start with endothelial cell oxidative stress. Yet newer data surprisingly finds that the avascular outer retina is the primary site of oxidative stress before microvascular histopathology in experimental DR. Importantly, correcting this early oxidative stress is sufficient to restore vision and mitigate the histopathology in diabetic models. However, translating these promising results into the clinic has been stymied by an absence of methods that can measure and optimize anti-oxidant treatment efficacy in vivo. Here, we review imaging approaches that address this problem. In particular, diabetes-induced oxidative stress impairs dark–light regulation of subretinal space hydration, which regulates the distribution of interphotoreceptor binding protein (IRBP). IRBP is a vision-critical, anti-oxidant, lipid transporter, and pro-survival factor. We show how optical coherence tomography can measure subretinal space oxidative stress thus setting the stage for personalizing anti-oxidant treatment and prevention of impactful declines and loss of vision in patients with diabetes.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zihe Huang ◽  
Ying Fang ◽  
He Huang ◽  
Xiaomei Xu ◽  
Jiwei Wang ◽  
...  

Retinal blood vessels are the only deep microvessels in the blood circulation system that can be observed directly and noninvasively, providing us with a means of observing vascular pathologies. Cardiovascular and cerebrovascular diseases, such as glaucoma and diabetes, can cause structural changes in the retinal microvascular network. Therefore, the study of effective retinal vessel segmentation methods is of great significance for the early diagnosis of cardiovascular diseases and the vascular network’s quantitative results. This paper proposes an automatic retinal vessel segmentation method based on an improved U-Net network. Firstly, the image patches are rotated to amplify the image data, and then, the RGB fundus image is preprocessed by normalization. Secondly, after the improved U-Net model is constructed with 23 convolutional layers, 4 pooling layers, 4 upsampling layers, 2 dropout layers, and Squeeze and Excitation (SE) block, the extracted image patches are utilized for training the model. Finally, the fundus images are segmented through the trained model to achieve precise extraction of retinal blood vessels. According to experimental results, the accuracy of 0.9701, 0.9683, and 0.9698, sensitivity of 0.8011, 0.6329, and 0.7478, specificity of 0.9849, 0.9967, and 0.9895, F1-Score of 0.8099, 0.8049, and 0.8013, and area under the curve (AUC) of 0.8895, 0.8845, and 0.8686 were achieved on DRIVE, STARE, and HRF databases, respectively, which is better than most classical algorithms.


2018 ◽  
Vol 159 (8) ◽  
pp. 320-326
Author(s):  
Cecília Czakó ◽  
Gábor László Sándor ◽  
Mónika Ecsedy ◽  
Zsuzsanna Szepessy ◽  
Ágnes Borbándy ◽  
...  

Abstract: Introduction: Optical coherence tomography angiography is a non-invasive imaging technique that is able to visualize the different retinal vascular layers using motion contrast to detect blood flow without intravenous dye injection. This method might help to assess microangiopathy in diabetic retinopathy during screening and follow-up. Aim: To quantify retinal microvasculature alterations in both eyes of diabetic patients in relation to systemic risk factors using optical coherence tomography angiography. Method: Both eyes of 36 diabetic patients and 45 individuals without diabetes were examined. Duration of diabetes, insulin therapy, blood pressure, HbA1c, dyslipidemia, axial length and the presence of diabetic retinopathy were recorded. Retinal vessel density was measured by optical coherence tomography angiography. The effect of risk factors on vessel density and between-eye asymmetry was assessed using multivariable regression analysis. Results: Vessel density was significantly lower and between-eye difference was significantly higher in diabetic patients compared to controls (p<0.05). Both vessel density and between-eye asymmetry significantly correlated with diabetes duration (p<0.05) after controlling for the effect of risk factors. The between-eye asymmetry in vessel density was significantly higher in patients without clinically detectable diabetic retinopathy compared to control subjects (p<0.001). Conclusions: There is a decrease in retinal vessel density and an increase in between-eye asymmetry in patients with diabetes compared to healthy subjects. By using optical coherence tomography angiography, the detection of these microvascular alterations is possible before clinically detectable diabetic retinopathy and might serve as a useful tool in both screening and timing of treatment. Orv Hetil. 2018; 159(8): 320–326.


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