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Choroidal structural analysis in eyes with diabetic retinopathy and diabetic macular edema—A novel OCT based imaging biomarker
摘要： To evaluate structural changes in the choroid among patients with diabetic macular edema (DME), with varying grades of diabetic retinopathy (DR), using enhance depth imaging spectral domain optical coherence tomography (EDI SD-OCT) scans. A cross-sectional study was conducted on 82 eyes with DR and DME and 86 healthy control eyes. Eyes with DME were classified according to the severity of DR as per the international DR severity scale. Sub foveal choroidal thickness (SFCT)was obtained using EDI SD-OCT scans. These scans were binarized into luminal and stromal areas, to derive the choroidal vascularity index (CVI). CVI and SFCT were analyzed between the study and control group using paired-T test. Tukey’s test was used to correlate the differences in CVI and SFCT between different grades of DR. Further analysis was done to look for the effect of DR severity and type of DME on CVI as well as SFCT using correlation coefficient and linear regression analysis. SFCT was significantly increased in eyes with DME as compared to the controls (334.47 ±51.81μm vs 284.53±56.45μm, p<0.001), and showed an ascending trend with worsening of DR, though this difference was not statistically significant [mild non-proliferative diabetic retinopathy (NPDR) = 304.33±40.39μm, moderate NPDR = 327.81±47.39μm, severe NPDR = 357.72±62.65μm, proliferative DR (PDR) = 334.59±47.4μm, p-0.09]. CVI was significantly decreased in DME with DR eyes as compared to controls (63.89±1.89 vs 67.51 ±2.86, p<0.001). CVI was also significantly decreased with worsening DR (mild NPDR = 66.38±0.3, moderate NPDR = 65.28±0.37, severe NPDR = 63.50±0.47, PDR = 61.27±0.9, p<0.001). SFCT and CVI are dynamic parameters that are affected by DME. Unlike CVI, SFCT is also affected by ocular and systemic factors like edema and hypertension. CVI may be a more accurate surrogate marker for DME and DR and can potentially be used to monitor the progression of DR.
关键词： choroidal vascularity index,diabetic macular edema,subfoveal choroidal thickness,optical coherence tomography,diabetic retinopathy
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Current Trends towards Converging Technologies (ICCTCT) - Coimbatore, India (2018.3.1-2018.3.3)] 2018 International Conference on Current Trends towards Converging Technologies (ICCTCT) - Detecting Hard Exudates In Retinal Fundus Images Using Convolutinal Neural Networks
摘要： The main objective of this project is to detect Exudates in retinal fundus images using Convolutional Neural Networks. Disorders in Retinal Images like Micro aneurysm, Hemorrhages, Hard Exudates, Soft Exudates, Macular Edema, Red lesions, Diabetic Retinopathy are likely to lead to severe visual loss Impairments. This work provides an automatic image processing techniques to diagnose Exudates in human eye and discussed various approaches used to detect Exudates in retinal images. Various publically available databases are listed and provide comparison between different approaches like SVM, KNN and CNN. Diabetic Retinopathy (DR) is the most essential causes of imaginative and prescient loss in diabetic patients. The most primary sign of DR is the presence of exudates, and detecting these in early screening is crucial in preventing vision loss. The automatic reputation of DR consisting of lesions, they are hard exudates (HEs), in fundus pix can make contributions to the diagnosis of this disease. On this take a look at, a fixed of functions from image regions are extracted and decided on the subset which quality discriminates between HEs and the retinal historical past. In proposed system, threshold based segmentation is used for extracting the features. After that, HOG (histogram of gradient), Classify the diseases using the convolutional Neural Network (CNN) classifier. The publicly available STARE of color fundus images was used for testing purposes and the values of sensitivity, specificity and accuracy were found as 96%, 98% and 99.68% respectively for the neural network based classification.
关键词： Hemorrhages,Diabetic Retinopathy,Edema,Microaneurysms,Red lesions,Retinopathy,Exudates
更新于2025-09-04 15:30:14
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Multifractal and Lacunarity Analyses of Microvascular Morphology in Eyes with Diabetic Retinopathy: A Projection Artifact Resolved Optical Coherence Tomography Angiography Study
摘要： Objective: To evaluate the degree of microvascular impairment in diabetic retinopathy using multifractal and lacunarity analyses and to compare the diagnostic ability between traditional Euclidean measures (fovea avascular zone area and vessel density) and fractal geometric features. Methods: This retrospective cross-sectional study included a total of 143 eyes of 94 patients with different stages of diabetic retinopathy. The retinal microvasculature was imaged by projection removed optical coherence tomography angiography. We examined the degree of association between fractal metrics of the retinal microvasculature and diabetic retinopathy severity. The area under the receiver operating characteristic curve was used to estimate the diagnostic performance. Results: With increasing diabetic retinopathy severity, the multifractal spectrum shifted towards the left bottom and exhibited less left skewness and asymmetry. The vessel density, multifractal features and lacunarity measured from the deep capillary plexus were strongly associated with diabetic retinopathy severity. The multifractal feature D5 showed the highest diagnostic ability. The combination of multifractal features further improved the discriminating power. Conclusions: Multifractal and lacunarity analyses can be potentially valuable tools for assessment of microvascular impairments in diabetic retinopathy. Multifractal geometric parameters exhibit a better discriminatory performance than Euclidean measures, particularly for detection of the early stages of diabetic retinopathy.
关键词： diabetic retinopathy,optical coherence tomography angiography,microvascular network,lacunarity,multifractal
更新于2025-09-04 15:30:14
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DETECTION OF DIABETIC RETINOPATHY USING OPTIC DISC
摘要： This paper proposes a method for the automatic detection of optic disc in retinal images. In the diagnosis and grading, the essential step is recognition of optic disk for diabetic retinopathy. The analysis of directional cross-section profile focused on the local maximum pixel of pre-processed image is realized by the proposed method using optic disc detection. Each profile is implemented by peak detection and property like shape, size, and height of the peak are estimated. The statistical measure of the estimated values for the attributes, where the orientation of the cross-section changes the constitute feature used in morphological classification to exclude encourages candidates. The result is to find the patient is affected by diabetics or not.
关键词： Optic disk,Diabetic retinopathy,Naives Bayes algorithm,Local maximum region
更新于2025-09-04 15:30:14
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[Advances in Intelligent Systems and Computing] Modelling and Simulation in Science, Technology and Engineering Mathematics Volume 749 (Proceedings of the International Conference on Modelling and Simulation (MS-17)) || Real Time Periodic Assessment of Retina of Diabetic Patients for Early Detection of Diabetic Retinopathy
摘要： Increase of diabetic patients in INDIA is in an alarming proportion. Uncontrolled diabetes can lead to blindness. Normally this is due to diabetic retinopathy. If it is detected earlier and required treatments are taken, blindness can be avoided. It may affect both the eyes simultaneously. Diabetic retinopathy is affected to 50% of diabetic patients. Diabetic Maculopathy and Diabetic Neuropathy are the common affected diseases in diabetic patients. The possibility of blindness for these types of patients is 25% more. Diabetic retinopathy is of two types: Non-proliferated diabetic retinopathy and Proliferated diabetic retinopathy [1, 2]. Vitreous heamorrhage and retinal detachments are the immediate complications leading to blindness, if proper treatment is not provided at the correct time. If it reaches to the complicated level and loses vision, then it is not possible to revert. Hence diabetic patients who are affected with vision may be monitored periodically to assess the real status of retina. Hence apart from a multi powered disease control approach, it is highly essential to utilize the advance technology enabling the doctors to have regular real time assessment of retinopathy in diabetic patients through telemedicine [3].
关键词： retina,blindness,telemedicine,Diabetic retinopathy,diabetes
更新于2025-09-04 15:30:14
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The automated detection of proliferative diabetic retinopathy using dual ensemble classification
摘要： Objective: Diabetic retinopathy (DR) is a retinal vascular disease that is caused by complications of diabetes. Proliferative diabetic retinopathy (PDR) is the advanced stage of the disease which carries a high risk of severe visual impairment. This stage is characterized by the growth of abnormal new vessels. We aim to develop a method for the automated detection of new vessels from retinal images. Methods: This method is based on a dual classification approach. Two vessel segmentation approaches are applied to create two separate binary vessel maps which each hold vital information. Local morphology, gradient and intensity features are measured using each binary vessel map to produce two separate 21-D feature vectors. Independent classification is performed for each feature vector using an ensemble system of bagged decision trees. These two independent outcomes are then combined to a produce a final decision. Results: Sensitivity and specificity results using a dataset of 60 images are 1.0000 and 0.9500 on a per image basis. Conclusions: The described automated system is capable of detecting the presence of new vessels.
关键词： Retinal images,Ensemble classification,Dual classification,New vessels,Proliferative diabetic retinopathy
更新于2025-09-04 15:30:14
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Sequence effect in the treatment of proliferative diabetic retinopathy with intravitreal ranibizumab and panretinal photocoagulation
摘要： Purpose: To compare the outcome of the sequence in the two treatments (intravitreal ranibizumab and panretinal photocoagulation) in high-risk proliferative diabetic retinopathy. Methods: This retrospective study included 35 patients with newly diagnosed high-risk proliferative diabetic retinopathy in 43 eyes; 18 (22 eyes) received intravitreal ranibizumab before panretinal photocoagulation (intravitreal ranibizumab+ group), while the other 17 (21 eyes) received panretinal photocoagulation before intravitreal ranibizumab (panretinal photocoagulation+ group). Each subject received three intravitreal ranibizumabs that were interleaved with three panretinal photocoagulations. The first treatment (either intravitreal ranibizumab or panretinal photocoagulation) was done 1 week before the second one. The interval between intravitreal ranibizumabs was 4 weeks, panretinal photocoagulation was 2 weeks. The power and pulse duration were determined based upon the status of each retinal spot before each panretinal photocoagulation. The retinal non-perfusion region was measured with fundus fluorescein angiography before and 1 month after the final treatment. The central macular thickness was measured with optical coherence tomography within 1 week before the first treatment, before each panretinal photocoagulation, and 1 month after the final intravitreal ranibizumab. Results: The panretinal photocoagulation energy required for effective treatment was lower in intravitreal ranibizumab+ group in the first and second sessions and in total energy (p < 0.05). Central macular thickness reduction before the second panretinal photocoagulation session was significant in the intravitreal ranibizumab+ group (p < 0.05). Conclusion: The sequence used in intravitreal ranibizumab+ group showed clear advantages over that in panretinal photocoagulation+ group in the treatment of proliferative diabetic retinopathy, not only in the use of lower energy for panretinal photocoagulation but also in the more rapid regression of neovascularization and less need of additional treatment.
关键词： proliferative diabetic retinopathy,panretinal photocoagulation,treatment sequence,Intravitreal ranibizumab
更新于2025-09-04 15:30:14
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Resistive Index of Ophthalmic Artery as a Bioimaging Biomarker for the Severity of Diabetic Retinopathy
摘要： Objective: To assess the resistive index (RI) of ophthalmic artery (OA) and central retinal artery (CRA) as a bioimaging biomarker for the severity of diabetic retinopathy, for the first time. Design: Tertiary care center based cross sectional study. Setting: RI in OA and CRA was studied using color Doppler and gray scale sonography. Central Subfield Thickness (CST), Cube Average Thickness (CAT), retinal photoreceptor ellipsoid zone (EZ) disruption, and Retinal Nerve Fiber Layer (RNFL) thickness were studied using SD-OCT. Participants: Sample size was calculated using 95% confidence interval. 69 consecutive cases of type 2 diabetes mellitus between the ages of 40 and 70 years were included after informed consent. According to Early Treatment Diabetic Retinopathy Study (ETDRS) classification cases were grouped as: diabetes mellitus with no retinopathy (No DR) (n=22); non-proliferative diabetic retinopathy (NPDR) (n=25); and Proliferative Diabetic Retinopathy (PDR) (n=22). Healthy control subjects of similar age were included (n=22). Main outcome measures: RI in OA and CRA. Results: A significant increase in RI of OA and CRA was observed with increased severity of DR. A significant positive correlation of RI of OA and CRA with CST, CAT and grades of EZ disruption and a negative correlation with RNFL thickness was observed. RI of OA was found to be a significant independent predictor of severity of DR [multivariate analysis OR=0.00, p<0.001; area under receiver operating characteristic curve analysis=0.941-1.000, p<0.001]. Conclusions: Resistive index of OA is a bio imaging biomarker for the severity of DR.
关键词： Retinal nerve fiber layer,Ophthalmic artery,Central retinal artery,Optical coherence tomography,Biomarkers,Resistive index,Diabetic retinopathy
更新于2025-09-04 15:30:14
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Knockdown of FOXO6 inhibits high glucose–induced oxidative stress and apoptosis in retinal pigment epithelial cells
摘要： Oxidative stress and apoptosis in retinal pigment epithelium cells are involved in the pathogenesis of diabetic retinopathy (DR). Forkhead box class O 6 (FOXO6) is a member of the FOXO family that can regulate diabetes‐induced oxidative stress. However, the role of FOXO6 in DR has not been clarified. The aim of the present study was to investigate the effects of FOXO6 on high glucose (HG)‐induced oxidative stress and apoptosis in ARPE‐19 cells. The results showed that FOXO6 was overexpressed in clinical vitreous samples from DR patients and in HG‐induced ARPE‐19 cells. Knockdown of FOXO6 by small interfeing RNA targeting FOXO6 (si‐FOXO6) mitigated the HG‐induced the production of reactive oxygen species and malondialdehyde, as well as the inhibition of superoxide dismutase activity. Knockdown of FOXO6 reduced the rate of cell apoptosis in HG‐induced ARPE‐19 cells. The increase in bax expression and decrease in bcl‐2 expression caused by HG stimulation were reversed by si‐FOXO6 transfection. Furthermore, knockdown of FOXO6 enhanced the activation of Akt/Nrf2 pathway in HG‐stimulated ARPE‐19 cells. Taken together, suppression of FOXO6 protects ARPE‐19 cells from HG‐induced oxidative stress and apoptosis, which is in part mediated by the activation of Akt/Nrf2 pathway.
关键词： Akt/Nrf2 pathway,oxidative stress,retinal pigment epithelium cells,forkhead box class O 6,diabetic retinopathy,apoptosis
更新于2025-09-04 15:30:14
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Multimodal Imaging of the Initial Stages of Diabetic Retinopathy. Different Disease Pathways in Different Patients
摘要： To evaluate the prevalence of different disease pathways (ischemia, neurodegeneration and edema) in the initial stages of diabetic retinopathy (DR). In this retrospective cross-sectional study, eyes were grouped by DR severity using the 7-field ETDRS protocol (levels 10-20, 35 and 43-47). Neurodegeneration was identified by thinning of the retinal nerve fiber layer (RNFL) and/or ganglion cell layer (GCL). Edema was identified by thickening of the inner nuclear layer (INL), outer plexiform layer (OPL), or full retina. Ischemia was identified by metrics of retinal vessel density. 142 eyes from 142 patients (28% women) aged 52-88 years were imaged. Vessel density (ischemia) was significantly different between ETDRS groups (p<0.020). On multivariate regression analysis, it remained significantly different between stages of the disease and showed associations with age (p<0.001), gender (p=0.028) and metabolic control (p=0.034). No significant differences between ETDRS groups were found in retinal thinning (neurodegeneration) or retinal thickness (edema). Eyes with the same ETDRS retinopathy grading from different diabetic patients show that the prevalence of different disease pathways, varies between patients even within the same severity group. Ischemia (capillary dropout) is the only disease pathway that shows correlation with retinopathy severity and metabolic control.
关键词： Retinal Edema,Ischemia,Neurodegeneration,Diabetic Retinopathy
更新于2025-09-04 15:30:14