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Journal of Ophthalmology 2014Early in the progression of diabetes, a paradoxical metabolic imbalance in inorganic phosphate (Pi) occurs that may lead to reduced high energy phosphate and tissue... (Review)
Review
Early in the progression of diabetes, a paradoxical metabolic imbalance in inorganic phosphate (Pi) occurs that may lead to reduced high energy phosphate and tissue hypoxia. These changes take place in the cells and tissues in which the entry of glucose is not controlled by insulin, particularly in poorly regulated diabetes patients in whom long-term vascular complications are more likely. Various conditions are involved in this disturbance in Pi. First, the homeostatic function of the kidneys is suboptimal in diabetes, because elevated blood glucose concentrations depolarize the brush border membrane for Pi reabsorption and lead to lack of intracellular phosphate and hyperphosphaturia. Second, during hyperglycemic-hyperinsulinemic intervals, high amounts of glucose enter muscle and fat tissues, which are insulin sensitive. Intracellular glucose is metabolized by phosphorylation, which leads to a reduction in plasma Pi, and subsequent deleterious effects on glucose metabolism in insulin insensitive tissues. Hypophosphatemia is closely related to a decrease in adenosine triphosphate (ATP) in the aging process and in uremia. Any interruption of optimal ATP production might lead to cell injury and possible cell death, and evidence will be provided herein that such cell death does occur in diabetic retinopathy. Based on this information, the mechanism of capillary microaneurysms formation in diabetic retinopathy and the pathogenesis of diabetic retinopathy must be reevaluated.
PubMed: 24782919
DOI: 10.1155/2014/135287 -
The British Journal of Ophthalmology Apr 1995Although microaneurysms are a clinicopathological hallmark of diabetic retinopathy, there have been few ultrastructural studies of these important lesions. As a result,...
BACKGROUND
Although microaneurysms are a clinicopathological hallmark of diabetic retinopathy, there have been few ultrastructural studies of these important lesions. As a result, knowledge of the mechanisms involved in the pathogenesis of microaneurysms remains fragmentary. This study provides histological and ultrastructural evidence of various stages in microaneurysm formation within the retinal vasculature.
METHODS
The eyes of three type II diabetic patients, obtained within 24 hours of death, were studied by the trypsin digest technique. Eyes from two further type II diabetics were fixed in 2.5% glutaraldehyde within 12 hours of death and processed for electron microscopy.
RESULTS
In the trypsin digest preparations, small saccular and fusiform microaneurysms were observed in the peripheral retinal. In the central retina, the microaneurysms ranged in morphology from thin walled, cellular forms to dense, acellular, hyalinised forms. Ultrastructurally, four distinct groups of microaneurysm were observed. Type I showed an extensive accumulation of polymorphonuclear cells into the lumen. The endothelium remained intact, although pericytes were invariably absent. Type II microaneurysms were typified by large numbers of red blood cells (RBCs) in the lumen. Endothelial cells and pericytes were completely absent. The type III microaneurysm was also non-perfused and contained aggregates of irregularly shaped RBC profiles and RBC breakdown products. Recanalisation by new vessels into the occluded lumen was observed in one microaneurysm. Type IV microaneurysms were almost or completely sclerosed, with extensive fibrosis and lipid infiltration into the lumen and basement membrane wall.
CONCLUSION
This investigation describes several distinctive stages in the formation of microaneurysms during diabetic retinopathy. With reference to the pathogenesis of retinal microaneurysms, the interaction of various cell types is discussed and the significance of vascular cell death and localised hypertensive events highlighted.
Topics: Aneurysm; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Erythrocytes; Humans; Microscopy, Electron; Neutrophils; Retinal Vessels
PubMed: 7742285
DOI: 10.1136/bjo.79.4.362 -
Multimedia Tools and Applications 2022Diabetic Retinopathy (DR) is defined as the Diabetes Mellitus difficulty that harms the blood vessels in the retina. It is also known as a silent disease and cause mild...
Diabetic Retinopathy (DR) is defined as the Diabetes Mellitus difficulty that harms the blood vessels in the retina. It is also known as a silent disease and cause mild vision issues or no symptoms. In order to enhance the chances of effective treatment, yearly eye tests are vital for premature discovery. Hence, it uses fundus cameras for capturing retinal images, but due to its size and cost, it is a troublesome for extensive screening. Therefore, the smartphones are utilized for scheming low-power, small-sized, and reasonable retinal imaging schemes to activate automated DR detection and DR screening. In this article, the new DIY (do it yourself) smartphone enabled camera is used for smartphone based DR detection. Initially, the preprocessing like green channel transformation and CLAHE (Contrast Limited Adaptive Histogram Equalization) are performed. Further, the segmentation process starts with optic disc segmentation by WT (watershed transform) and abnormality segmentation (Exudates, microaneurysms, haemorrhages, and IRMA) by Triplet half band filter bank (THFB). Then the different features are extracted by Haralick and ADTCWT (Anisotropic Dual Tree Complex Wavelet Transform) methods. Using life choice-based optimizer (LCBO) algorithm, the optimal features are chosen from the mined features. Then the selected features are applied to the optimized hybrid ML (machine learning) classifier with the combination of NN and DCNN (Deep Convolutional Neural Network) in which the SSD (Social Ski-Driver) is utilized for the best weight values of hybrid classifier to categorize the severity level as mild DR, severe DR, normal, moderate DR, and Proliferative DR. The proposed work is simulated in python environment and to test the efficiency of the proposed scheme the datasets like APTOS-2019-Blindness-Detection, and EyePacs are used. The model has been evaluated using different performance metrics. The simulation results verified that the suggested scheme is provides well accuracy for each dataset than other current approaches.
PubMed: 35233182
DOI: 10.1007/s11042-022-12103-y -
Scientific Reports May 2021Diabetic retinopathy (DR) is a leading cause of blindness and affects millions of people throughout the world. Early detection and timely checkups are key to reduce the...
Diabetic retinopathy (DR) is a leading cause of blindness and affects millions of people throughout the world. Early detection and timely checkups are key to reduce the risk of blindness. Automated grading of DR is a cost-effective way to ensure early detection and timely checkups. Deep learning or more specifically convolutional neural network (CNN)-based methods produce state-of-the-art performance in DR detection. Whilst CNN based methods have been proposed, no comparisons have been done between the extracted image features and their clinical relevance. Here we first adopt a CNN visualization strategy to discover the inherent image features involved in the CNN's decision-making process. Then, we critically analyze those features with respect to commonly known pathologies namely microaneurysms, hemorrhages and exudates, and other ocular components. We also critically analyze different CNNs by considering what image features they pick up during learning to predict and justify their clinical relevance. The experiments are executed on publicly available fundus datasets (EyePACS and DIARETDB1) achieving an accuracy of 89 ~ 95% with AUC, sensitivity and specificity of respectively 95 ~ 98%, 74 ~ 86%, and 93 ~ 97%, for disease level grading of DR. Whilst different CNNs produce consistent classification results, the rate of picked-up image features disagreement between models could be as high as 70%.
Topics: Algorithms; Datasets as Topic; Deep Learning; Diabetic Retinopathy; Humans; Neural Networks, Computer; Sensitivity and Specificity
PubMed: 33958686
DOI: 10.1038/s41598-021-89225-0 -
American Journal of Ophthalmology Case... Mar 2022To describe a novel finding of angiographic dark choroid in a patient with systemic non-hereditary amyloidosis.
PURPOSE
To describe a novel finding of angiographic dark choroid in a patient with systemic non-hereditary amyloidosis.
OBSERVATION
A 43-year old female with systemic light-chain amyloidosis associated with advanced kidney disease presented with metamorphopsia and blurry vision in both eyes of 1 year duration. Examination revealed subretinal yellowish deposits in the central macula and mid-periphery with patchy RPE mottling bilaterally. OCT demonstrated thickened choroid with a widened hyporeflective sub-Bruch's choriocapillaris band. FAF showed hypoautofluorescence of the central maculae with hyperautofluorescence flecks perifoveally. Fluorescein angiography demonstrated normal vascular filling without leakage and peripheral microaneurysms. The FA also revealed a strikingly diminished diffuse lack of choroidal fluorescence throughout all angiographic phases in both eyes which has not been previously described in this condition.
CONCLUSIONSAND IMPORTANCE
This case demonstrates that patients with systemic amyloidosis may exhibit attenuation of choroidal signal ("dark choroid") on fluorescein angiography, possibly due to accumulation of amyloid material in the sub-RPE space.
PubMed: 35198799
DOI: 10.1016/j.ajoc.2022.101334 -
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi =... Aug 2022Microaneurysm is the initial symptom of diabetic retinopathy. Eliminating this lesion can effectively prevent diabetic retinopathy in the early stage. However, due to...
Microaneurysm is the initial symptom of diabetic retinopathy. Eliminating this lesion can effectively prevent diabetic retinopathy in the early stage. However, due to the complex retinal structure and the different brightness and contrast of fundus image because of different factors such as patients, environment and acquisition equipment, the existing detection algorithms are difficult to achieve the accurate detection and location of the lesion. Therefore, an improved detection algorithm of you only look once (YOLO) v4 with Squeeze-and-Excitation networks (SENet) embedded was proposed. Firstly, an improved and fast fuzzy c-means clustering algorithm was used to optimize the anchor parameters of the target samples to improve the matching degree between the anchors and the feature graphs; Then, the SENet attention module was embedded in the backbone network to enhance the key information of the image and suppress the background information of the image, so as to improve the confidence of microaneurysms; In addition, an spatial pyramid pooling was added to the network neck to enhance the acceptance domain of the output characteristics of the backbone network, so as to help separate important context information; Finally, the model was verified on the Kaggle diabetic retinopathy dataset and compared with other methods. The experimental results showed that compared with other YOLOv4 network models with various structures, the improved YOLOv4 network model could significantly improve the automatic detection results such as F-score which increased by 12.68%; Compared with other network models and methods, the automatic detection accuracy of the improved YOLOv4 network model with SENet embedded was obviously better, and accurate positioning could be realized. Therefore, the proposed YOLOv4 algorithm with SENet embedded has better performance, and can accurately and effectively detect and locate microaneurysms in fundus images.
Topics: Algorithms; Diabetic Retinopathy; Fundus Oculi; Humans; Microaneurysm
PubMed: 36008335
DOI: 10.7507/1001-5515.202203022 -
Renal Failure 2023Previous studies have shown a relationship between retinopathy and cognition including population with and without chronic kidney disease (CKD) but data regarding... (Observational Study)
Observational Study
Previous studies have shown a relationship between retinopathy and cognition including population with and without chronic kidney disease (CKD) but data regarding peritoneal dialysis (PD) are limited. This study aims to investigate the relationship between retinopathy and cognitive impairment in patients undergoing peritoneal dialysis (PD). In this observational study, we recruited a total of 107 participants undergoing PD, consisting of 48 men and 59 women, ages ranging from 21 to 78 years. The study followed a cross-sectional design. Retinal microvascular characteristics, such as geometric changes in retinal vascular including tortuosity, fractal dimension (FD), and calibers, were assessed. Retinopathy (such as retinal hemorrhage or microaneurysms) was evaluated using digitized photographs. The Modified Mini-Mental State Examination (3MS) was performed to assess global cognitive function. The prevalence rates of retinal hemorrhage, microaneurysms, and retinopathy were 25%, 30%, and 43%, respectively. The mean arteriolar and venular calibers were 63.2 and 78.5 µm, respectively, and the corresponding mean tortuosity was 37.7 ± 3.6 and 37.2 ± 3.0 mm. The mean FD was 1.49. After adjusting for age, sex, education, mean arterial pressure, and Charlson index, a negative association was revealed between retinopathy and 3MS scores (regression coefficient: -3.71, 95% confidence interval: -7.09 to -0.33, = 0.03). Retinopathy, a condition common in patients undergoing PD, was associated with global cognitive impairment. These findings highlight retinopathy, can serve as a valuable primary screening tool for assessing the risk of cognitive decline.
Topics: Male; Humans; Female; Retinal Hemorrhage; Cross-Sectional Studies; Microaneurysm; Retinal Diseases; Cognitive Dysfunction; Cognition; Peritoneal Dialysis
PubMed: 37732397
DOI: 10.1080/0886022X.2023.2258989 -
BMC Ophthalmology Nov 2022The aim of this study was to evaluate the structural retinal vascular integrity using optical coherence tomography angiography (OCTA) in treatment-naïve eyes with...
BACKGROUND
The aim of this study was to evaluate the structural retinal vascular integrity using optical coherence tomography angiography (OCTA) in treatment-naïve eyes with diabetic macular edema (DME) and to compare it with findings in diabetic eyes without DME.
METHODS
In this prospective study, 70 eyes with diabetic retinopathy were included (37 eyes with DME and 33 eyes without DME). The medical records, including swept-source optical coherence tomography and 9 × 9 mm swept-source OCTA images were reviewed and compared between DME and non-DME groups. Microaneurysms, intraretinal microvascular abnormalities (IRMA), areas of capillary non perfusion, foveal avascular zone (FAZ), and capillary vascular density (CVD) were analyzed in the superficial capillary plexus (SCP) and the deep capillary plexus (DCP).
RESULTS
Compared to the non-DME eyes, DME eyes had more microaneurysms in the SCP and the DCP (p = 0,039 and p = 0,024 respectively), more IRMA in the SCP (p = 0,005), larger areas of capillary non perfusion in the SCP and the DCP (p = 0,026 and p = 0,02 respectively) and larger FAZ in both plexuses (p = 0,048 in the SCP and p = 0,012 in the DCP). The CVD in the DCP was lower in DME eyes compared to non-DME eyes (p = 0,007). The severity of DME was significantly correlated to the number of microaneurysms and to the FAZ surface. Central macular thickness was significantly correlated with the number of microaneurysms in the DCP, the surface of capillary non perfusion areas and the FAZ area in both plexuses.
CONCLUSIONS
OCTA with a 9 × 9 mm field of view showed that the retinal vascular integrity regarding the number of microaneurysms, the number of IRMA, the surface of capillary non perfusion areas, the FAZ area and the CVD, was significantly more impaired in DME eyes compared to diabetic eyes without DME. The DCP seemed to be more affected in diabetic eyes with and without DME than the SCP.
Topics: Humans; Diabetic Retinopathy; Tomography, Optical Coherence; Macular Edema; Fluorescein Angiography; Microaneurysm; Retinal Vessels; Prospective Studies; Visual Acuity; Diabetes Mellitus
PubMed: 36329416
DOI: 10.1186/s12886-022-02632-3 -
Scientifica 2016Diabetic retinopathy is caused by the retinal micro vasculature which may be formed as a result of diabetes mellitus. Blindness may appear as a result of unchecked and... (Review)
Review
Diabetic retinopathy is caused by the retinal micro vasculature which may be formed as a result of diabetes mellitus. Blindness may appear as a result of unchecked and severe cases of diabetic retinopathy. Manual inspection of fundus images to check morphological changes in microaneurysms, exudates, blood vessels, hemorrhages, and macula is a very time-consuming and tedious work. It can be made easily with the help of computer-aided system and intervariability for the observer. In this paper, several techniques for detecting microaneurysms, hemorrhages, and exudates are discussed for ultimate detection of nonproliferative diabetic retinopathy. Blood vessels detection techniques are also discussed for the diagnosis of proliferative diabetic retinopathy. Furthermore, the paper elaborates a discussion on the experiments accessed by authors for the detection of diabetic retinopathy. This work will be helpful for the researchers and technical persons who want to utilize the ongoing research in this area.
PubMed: 27777811
DOI: 10.1155/2016/6838976 -
CEN Case Reports May 2018An 80-year-old woman was admitted to the hospital complaining of loss of appetite. 10 days earlier, her oral intake gradually decreased with no other specific symptoms,...
An 80-year-old woman was admitted to the hospital complaining of loss of appetite. 10 days earlier, her oral intake gradually decreased with no other specific symptoms, such as abdominal pain, nausea, vomiting, headache, or low back pain. Abdominal computed tomography (CT) scan revealed a left subcapsular renal hematoma. We suspected infective subcapsular renal hematoma, so percutaneous needle aspiration and drainage were performed. Intravenous sulbactam-ampicillin was started immediately. On day 9 after admission, repeat CT scan revealed the subcapsular hematoma had reduced in size. The drain was removed, and intravenous antibiotics were discontinued. Follow-up CT scan on day 21 revealed increased subcapsular renal hematoma size. The patient also had high fever. Suspecting recurrence of infective subcapsular renal hematoma, we repeated the drainage of the hematoma and restarted intravenous antibiotics. Renal arteriography showed a renal artery microaneurysm and her condition improved with renal artery embolization. Renal arteriography was useful for detecting renal artery microaneurysm in infective subcapsular renal hematoma that did not resolve after antibiotic treatment and drainage.
PubMed: 29344911
DOI: 10.1007/s13730-018-0305-6