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Multimodal imaging and treatment of Purtscher-like retinopathy
摘要： A 52-year-old patient with multiple cardiovascular risk factors referred for unilateral, acute, and painless visual loss. In the fundoscopic image there was significant papillary inflammation with tortuosity at this level and hemorrhages. Ophthalmological examination showed papillary inflammation, macular edema, and involvement in retinal inner layers. The control fluorescein angiography and optical coherence tomography angiography showed areas of central and peripheral ischemia. Given the clinical findings and background of the patient, the diagnosis of Purtscher-like retinopathy was reached and treatment with intravitreal dexamethasone was decided. Purtscher-like retinopathy is a rare entity that occurs in patients with multiple systemic pathologies, but without a traumatic background, which differentiates it from Purstcher's retinopathy. The diagnosis and early intervention are important in the prognosis. There are no therapeutic protocols, but good results have been obtained with intravitreal therapy with dexamethasone.
关键词： Purtscher flecken,Purtscher-like retinopathy,Purtscher retinopathy,Optical coherence tomography angiography,Optical coherence tomography
更新于2025-09-23 15:23:52
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An enhanced diabetic retinopathy detection and classification approach using deep convolutional neural network
摘要： The objective of this study is to propose an alternative, hybrid solution method for diagnosing diabetic retinopathy from retinal fundus images. In detail, the hybrid method is based on using both image processing and deep learning for improved results. In medical image processing, reliable diabetic retinopathy detection from digital fundus images is known as an open problem and needs alternative solutions to be developed. In this context, manual interpretation of retinal fundus images requires the magnitude of work, expertise, and over-processing time. So, doctors need support from imaging and computer vision systems and the next step is widely associated with use of intelligent diagnosis systems. The solution method proposed in this study includes employment of image processing with histogram equalization, and the contrast limited adaptive histogram equalization techniques. Next, the diagnosis is performed by the classification of a convolutional neural network. The method was validated using 400 retinal fundus images within the MESSIDOR database, and average values for different performance evaluation parameters were obtained as accuracy 97%, sensitivity (recall) 94%, specificity 98%, precision 94%, FScore 94%, and GMean 95%. In addition to those results, a general comparison of with some previously carried out studies has also shown that the introduced method is efficient and successful enough at diagnosing diabetic retinopathy from retinal fundus images. By employing the related image processing techniques and deep learning for diagnosing diabetic retinopathy, the proposed method and the research results are valuable contributions to the associated literature.
关键词： Image processing,Deep learning,Convolutional neural network,Diabetic retinopathy
更新于2025-09-23 15:23:52
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Computer-Assisted Diagnosis for Diabetic Retinopathy Based on Fundus Images Using Deep Convolutional Neural Network
摘要： Diabetic retinopathy (DR) is a complication of long-standing diabetes, which is hard to detect in its early stage because it only shows a few symptoms. Nowadays, the diagnosis of DR usually requires taking digital fundus images, as well as images using optical coherence tomography (OCT). Since OCT equipment is very expensive, it will benefit both the patients and the ophthalmologists if an accurate diagnosis can be made, based solely on reading digital fundus images. In the paper, we present a novel algorithm based on deep convolutional neural network (DCNN). Unlike the traditional DCNN approach, we replace the commonly used max-pooling layers with fractional max-pooling. Two of these DCNNs with a different number of layers are trained to derive more discriminative features for classification. After combining features from metadata of the image and DCNNs, we train a support vector machine (SVM) classifier to learn the underlying boundary of distributions of each class. For the experiments, we used the publicly available DR detection database provided by Kaggle. We used 34,124 training images and 1,000 validation images to build our model and tested with 53,572 testing images. The proposed DR classifier classifies the stages of DR into five categories, labeled with an integer ranging between zero and four. The experimental results show that the proposed method can achieve a recognition rate up to 86.17%, which is higher than previously reported in the literature. In addition to designing a machine learning algorithm, we also develop an app called 'Deep Retina.' Equipped with a handheld ophthalmoscope, the average person can take fundus images by themselves and obtain an immediate result, calculated by our algorithm. It is beneficial for home care, remote medical care, and self-examination.
关键词： deep convolutional neural network,mobile app,fractional max-pooling,support vector machine,diabetic retinopathy,fundus images,teaching-learning-based optimization
更新于2025-09-23 15:23:52
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Retinal photoreceptor apoptosis is associated with impaired serum ionized calcium homeostasis in diabetic retinopathy: An in-vivo analysis
摘要： Purpose: The aim of this work was to study the association of serum ionized calcium with retinal photoreceptor apoptosis on spectral domain optical coherence tomography (SD-OCT) in diabetic retinopathy (DR). Methods: Sixty consecutive cases with Type 2 diabetes mellitus were categorized into three groups: no diabetic retinopathy; non-proliferative DR; proliferative DR. The eye with more severe form of the disease was considered. Twenty healthy controls were also included. Best corrected visual acuity (BCVA) was measured on logMAR scale. Retinal photoreceptor apoptosis was defined as disruption of retinal photoreceptor ellipsoid zone (EZ). Ellipsoid zone disruption was assessed using SD-OCT. Serum levels of total and ionized calcium were measured using standard protocol. Results: EZ disruption was found to be positively associated with serum total calcium and ionized calcium. Also, EZ disruption was found to be positively associated with logMAR BCVA. Conclusion: Increased serum ionized calcium induces retinal photoreceptor apoptosis resulting in increased EZ disruption in DR.
关键词： Ionized calcium,Retinal photoreceptor apoptosis,Diabetic retinopathy,Autophagy,Ellipsoid zone,Spectral-domain optical coherence tomography
更新于2025-09-23 15:23:52
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[Communications in Computer and Information Science] Advances in Signal Processing and Intelligent Recognition Systems Volume 968 (4th International Symposium SIRS 2018, Bangalore, India, September 19–22, 2018, Revised Selected Papers) || A Comprehensive Review on Automatic Diagnosis of Diabetic Maculopathy in Retinal Fundus Images
摘要： Diabetic Maculopathy (DM) is one of the major problems of diabetes mellitus and it is one of the key reasons for the vision problem. It arises due to the leakage of blood from injured retinal veins. The development of DM is moderate and soundless and it is found in 10% of the world diabetic population. If diabetic maculopathy is not noticed in the underlying stage the effect this on macula is irreversible and can prompt vision loss. Therefore, screening of diabetic eye helps in finding diabetic maculopathy at the beginning stage which prevents the vision loss. In this review paper, the anatomy of the human eye and a brief overview of diabetes, diabetic retinopathy and diabetic maculopathy is presented. The literature review of various methods/techniques used for detection of DM in retinal fundus images and the performance metrics used to measure these methods are discussed in details. Issues involved in DM detection are also mentioned in this paper.
关键词： Blood vessels (BVs),Diabetic maculopathy (DM),Hard exudates (HEs),Retinopathy (DR),Optic disc (OD)
更新于2025-09-23 15:23:52
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Baicalin protects human retinal pigment epithelial cell lines against high glucose-induced cell injury by up-regulation of microRNA-145
摘要： Background: Diabetic retinopathy (DR) is a common complication of diabetes mellitus, which is a major reason of blindness. Baicalin (BAI) is a flavonoid extracted from Scutellaria baicalensis, whose pharmacological characterizes have been widely reported in various diseases. However, it remains unclear the effect of BAI on DR. The study aimed to confirm the protective effect of BAI on DR. Methods: ARPE-19 cells and HRMECs were exposed to the high glucose (HG) environment to construct a cell injury model. After treatment with HG and BAI, cell viability, apoptosis, inflammatory cytokines and ROS generations were determined in ARPE-19 cells and HRMECs. Subsequently, miR-145 inhibitor and its negative control were transfected into ARPE-19 cells, and the regulatory effects on HG-and BAI-co-treated cells were detected. NF-κB and p38MAPK signaling pathways were finally examined to state the underling mechanism. Results: HG treatment significantly induced ARPE-19 cells and HRMECs injury in vitro. BAI significantly promoted cell proliferation, reduced apoptosis, as well as inhibited the release of IL-1β, IL-6, IL-8 and ROS in HG- injured ARPE-19 cells and HRMECs. Additionally, the expression level of miR-145 was up-regulated in HG-and BAI-co-treated cells. More importantly, miR-145 inhibition reversed the protective effect of BAI on HG- injured ARPE-19 cells. Besides, we observed that BAI inhibited the activation of NF-κB and p38MAPK pathways by up-regulating miR-145. Conclusions: Results demonstrated that BAI exhibited the protective effect against HG-induced cell injury by up-regulation of miR-145.
关键词： microRNA-145,diabetic retinopathy,p38MAPK,NF-κB,baicalin
更新于2025-09-23 15:23:52
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Comparison of fluorescein angiographic findings in type 1 and type 2 retinopathy of prematurity with intravitreal bevacizumab monotherapy and spontaneous regression
摘要： Purpose To investigate the extent of vascularization of the peripheral retina and vascular development patterns in patients with type 1 retinopathy of prematurity (ROP) treated with intravitreal injection of bevacizumab (IVB) and compare fluorescein angiography (FA) findings of them to those seen in patients with type 2 ROP who have recovered spontaneously. Methods Between May 2014 and September 2016, patients with type 1 ROP who had a single 0.025 ml (0.625 mg) IVB were evaluated as study group. On the other hand, type 2 ROP patients with stage 2 or stage 3 ROP in zone II without plus disease on indirect ophthalmoscopy were not treated and included as a control group. The progression of ROP and vascularization of retina were evaluated by FA under sedation analgesia in all patients. Results Sixty-two eyes of 31 premature infants were included in the study: 36 eyes/18 patients were treated for type 1 ROP and 26 eyes/13 patients were followed conservatively with the diagnoses of type 2 ROP. In the last FA examination among the study group, vascular terminal was in zone II in 8 eyes/4 patients (22.22%) and in zone III in 28 eyes/14 patients (77.78%). Vascular terminal was in zone III in all eyes of the control group (100%). We noted circumferential vessels in 12 eyes/8 patients (33.3%) and 7 eyes/5 patients (26.92%) in the study and control groups, respectively. Abnormal branching was noticed in 13 eyes/7 patients (46.42%) in the control group, whereas it was not detected in the study group. Arteriovenous shunts were noted in 1 eye of a patient in the study group and in 5 eyes/4 patients in the control group. In 6 eyes/3 patients among the study group, we performed laser photocoagulation to the avascular retina because of profound vascular leakage. Conclusion Peripheral vascular abnormalities probably occur as a result of ROP itself because similar FA findings were detected both in type 1 and type 2 ROP patients with or without treatment, although significantly less in IVB-treated group. Retinal vascularization usually reaches the farthermost limits with time even though it slows down in eyes treated with IVB, indicating the importance of a longer follow-up.
关键词： Fluorescein angiography,Bevacizumab,Peripheral vascular abnormalities,Retinopathy of prematurity
更新于2025-09-23 15:23:52
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Expression and significance of the Hedgehog signal transduction pathway in oxygen-induced retinal neovascularization in mice
摘要： Aim: The aim of the study was to investigate the signal transduction mechanism of Hedgehog–vascular endothelial growth factor in oxygen-induced retinopathy (OIR) and the effects of cyclopamine on OIR. Methods: An OIR model was established in C57BL/6J mice exposed to hyperoxia. Two hundred mice were randomly divided into a control group, an OIR group, an OIR-control group (treated with isometric phosphate-buffered saline by intravitreal injection), and a cyclopamine group (treated with cyclopamine by intravitreal injection), with 50 mice in each group. The retinal vascular morphology was observed using adenosine diphosphatase and number counting using hematoxylin and eosin-stained image. Quantitative real-time quantitative polymerase chain reaction was used to detect mRNA expression. Protein location and expression were evaluated using immunohistochemistry and Western blot. Results: The OIR group and OIR-control group demonstrated large-area pathological neovascularization and nonperfused area when compared with the control group (both P<0.05). The area of nonperfusion and neovascularization in the cyclopamine group was significantly reduced compared with the OIR and OIR-control groups (both P<0.05). Compared with the control group, the OIR and OIR-control groups had more vascular endothelial cells breaking through the inner limiting membrane. The number of new blood vessel endothelial cell nuclei in the cyclopamine group was significantly reduced (both P<0.05) when compared with the OIR and OIR-control groups. The mRNA and protein expressions of Smoothened, Gli1, and vascular endothelial growth factor in the signal pathway of the OIR and OIR-control groups were significantly higher than those of the control group; however, in the cyclopamine group, these factors were reduced when compared with the OIR and OIR-control groups (all P<0.05). Conclusion: Our data suggest that abnormal expression of the Hedgehog signaling pathway may be closely associated with the formation of OIR. Inhibiting the Smoothened receptor using cyclopamine could control retinal neovascularization, providing new ideas and measures for the prevention of oxygen-induced retinal neovascularization.
关键词： neovascularization,retinopathy of prematurity,oxygen-induced retinopathy,Hedgehog signaling pathway,cyclopamine
更新于2025-09-23 15:22:29
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Multimodal imaging in perifoveal exudative vascular anomalous complex with co-existent diabetic retinopathy
摘要： Perifoveal exudative vascular anomalous complex (PEVAC) is a recently described macular entity, which can be overlooked or confused with other retinal pathologies. On the basis of multimodal imaging features of 15 eyes with PEVAC, Sacconi et al.1 defined a PEVAC lesion as a unilateral, isolated, perifoveal, aneurysmal abnormality, occurring in otherwise healthy individuals, having characteristic angiographic and tomographic features and typically resistant to anti-vascular endothelial growth factor (anti-VEGF) therapy. Clinically, a PEVAC lesion is associated with intra-retinal fluid, haemorrhage and/or hard exudates. Querques et al.2 reported two cases of PEVAC and described the related angiographic and optical coherence tomography (OCT) features. In particular, there were no features of arterial hypertension, diabetes, or any other systemic or local vasculopathy, or signs of age-related macular degeneration. Multimodal imaging, in particular OCT-angiography along with OCT, fluorescein angiography and indocyanine angiography, have been used to provide a better understanding of the pathophysiological mechanisms of PEVAC. The purpose of this case report is to describe the imaging findings of a PEVAC lesion in a patient who had features of diabetic retinopathy.
关键词： aneurysm,perifoveal exudative vascular anomalous complex,diabetic retinopathy
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 21st International Multi-Topic Conference (INMIC) - Karachi, Pakistan (2018.11.1-2018.11.2)] 2018 IEEE 21st International Multi-Topic Conference (INMIC) - Textural and Intensity Feature Based Retinal Vessels Classification for the Identification of Hypertensive Retinopathy
摘要： Hypertensive retinopathy is a retinal disease which results as a consequence of high blood pressure. Its early detection is necessary in reducing the likelihood of permanent visual damage. The percentage of people suffering from Hypertension is high, so it is required to develop a system which automatically detects the presence of this disease. High blood pressure damages retinal vessels and due to which arteries width is reduced. This damage can be analyzed by extracting the blood vessels, classifying the segmented vessels into veins and arteries and their Arteriovenous Ratio, which is an important measure to establish whether a person is suffering from Hypertensive Retinopathy or not. This research presents a technique for automatic classification of blood vessels of retina using different classifiers and the performance of each classifier is compared on same feature set. A novel combination of features is used for classification of vessels, which is an essential step for calculation of Arteriovenous Ratio and subsequently the detection of Hypertensive Retinopathy. MATLAB has been used for this research. The results that are achieved using the proposed feature set show’s 89% accuracy.
关键词： Accuracy (ACC),Arteriovenous Ratio (AVR),Support Vector Machine (SVM),Armed Forces Institute of Ophthalmology (AFIO),Hypertensive Retinopathy (HR)
更新于2025-09-23 15:22:29