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Quantification of the Changes in the Openness of the Major Temporal Arcade in Retinal Fundus Images of Preterm Infants With Plus Disease
摘要： PURPOSE. We tested the hypothesis that the openness of the major temporal arcade (MTA) changes in the presence of plus disease, by quanti?cation via parabolic modeling of the MTA, as well as measurement of an arcade angle for comparative analysis. Such analysis could assist in the detection and treatment of progressive retinopathy of prematurity. METHODS. Digital image processing techniques were applied for the detection and modeling of the MTA via a graphical user interface (GUI) to quantify the openness of the MTA. An arcade angle measure, based on a previously proposed method, also was obtained via the GUI for comparative analysis. The statistical signi?cance of the differences between the plus and no-plus cases for each parameter was analyzed using the P value. The area (Az) under the receiver operating characteristic curve was used to assess the diagnostic performance of each feature. RESULTS. The temporal arcade angle measure and the openness parameter of the parabolic model were used to perform discrimination of plus versus no-plus cases. Using a set of 19 cases with plus and 91 with no plus disease, Az ? 0.70 was obtained using the results of dual-parabolic modeling in screening for plus disease. The arcade angle measure provided comparable results with Az ? 0.73. CONCLUSIONS. Using our proposed image analysis techniques and software, this study demonstrates, for the ?rst time to our knowledge, that the openness of the MTA decreases in the presence of plus disease.
关键词： plus disease,computer-aided diagnosis,retinopathy of prematurity,major temporal arcade,digital image analysis
更新于2025-09-23 15:22:29
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HMGB1 siRNA can reduce damage to retinal cells induced by high glucose in vitro and in vivo
摘要： Background: Diabetic retinopathy (DR), one of the most common complications of late-phase diabetes, is associated with many risk factors, among which continuous low-grade inflammation is one of the principal ones. As such, lowering inflammation levels and maintain the viability of human retinal endothelial cells (HRECs) are critical for DR therapy. HMGB1 is a well-known proinflammatory cytokine. However, whether HMGB1 small interfering RNA (siRNA) can protect retina cells under a high-glucose environment from morphological changes and functional abnormalities remain undetermined. We aimed to investigate the effect of HMGB1 siRNA on retinal cells in DR. Materials and methods: A total of 80 adult Wistar rats were randomly divided into four groups (n=20 each): normal control, diabetes mellitus (DM), scrambled (Scr) siRNA, and HMGB1 siRNA. Rats in the DM, Scr siRNA, and siRNA groups were established by intraperitoneal injection of streptozotocin. At 16 weeks after injection, rats in the siRNA and Scr-siRNA groups were intravitreally injected with 2 μL HMGB1 siRNA and 2 μL Scr-siRNA, while rats in the control and DM groups were intravitreally injected with the same dose of sterile saline. At 1 week after injections, we performed the following experiments. Immunohistochemical staining and real-time quantitative polymerase chain reaction were performed to test HMGB1 protein and messenger RNA expression in retinas. We performed TUNEL assays to detect retinal cell apoptosis and electroretinography to detect retinal function. In HRECs treated with high glucose, proliferation, morphology, apoptosis, superoxide dismutase (SOD), and reactive oxygen species production were detected. Western blot was applied to determine the expressions of HMGB1 and its related protein and apoptosis protein. Results: Intravitreal injection of HMGB1 siRNA reduced protein and messenger RNA expression of HMGB1 (both P,0.05). Intravitreal injection of HMGB1 siRNA reduced apoptosis of retinal cells (P,0.05), protected morphological changes in the retina, and improved the function of the retina (P,0.05). In HRECs treated with high glucose, HMGB1 siRNA pretreatment increased cell viability, reduced cell apoptosis, and reduced oxidative damage to cells (all P,0.05). Western blot detection found that HMGB1 siRNA pretreatment can inhibit the expression of cleaved caspase 3 and improve the expression of BCL2 (P,0.05). HMGB1 and NFκB expression increased in a time-dependent manner in the high-glucose environment and IKKβ and NFκB protein expression decreased significantly after HMGB1 silencing. Conclusion: As a therapeutic target, HMGB1 siRNA can reduce retinal cell damage induced by high glucose in vitro and in vivo and delay DR progress through the HMGB1–IKKβ–NFκB signaling pathway.
关键词： small interfering RNA,diabetic retinopathy,human retinal endothelial cells,inhibitor of nuclear factor κB,nuclear factor κB,high-mobility group box 1
更新于2025-09-23 15:22:29
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The assessment of autofluorescence of the crystalline lens in diabetic patients and healthy controls: can it be used as a screening test?
摘要： Background: Our purpose was to demonstrate if measuring lens autofluorescence (AF) with a scanning confocal biomicroscope may be used to identify subjects with undiagnosed type II diabetes mellitus (DM), and hence, for it to be used as a marker for the severity of diabetic retinopathy in diabetic patients. Patients and methods: In this cross-sectional, comparative study, lens AF was measured with scanning confocal lens fluorescence biomicroscope in diabetic and healthy groups. Full ophthalmological examination was performed. Blood tests of fasting plasma glucose, and glycosylated hemoglobin were also analyzed. The correlation between lens AF results and blood tests was evaluated in both groups. The cutoff value for the diagnosis of DM using lens AF was investigated. Results: The study included 191 subjects with a mean age of 52.09±6.75 years. One hundred and seven (56.0%) subjects were female, and 84 (44.0%) were male. Eighty-two (42.9%) patients had type II DM, and 109 (57.1%) subjects self-reported as normal. The fluorescence ratio (FR) values ranged from 0.09 to 0.46 (0.23±0.06) in the total group. Mean FR measurements of diabetic subjects were significantly higher (0.27±0.06) than those without DM (0.20±0.05), ( p=0.001). A statistically significant correlation was found between glycosylated hemoglobin, fasting plasma glucose, and FR. The cutoff point for the FR according to the presence of DM was found to be 0.24 and above ( p=0.001), with a sensitivity of 71.95% and a specificity of 80.73%. Conclusion: Measuring AF of human lens as an indirect evidence of increased advanced glycation end products may helpful in detecting impaired glucose metabolism. Our results show highly significant correlation between possibility of DM and FR.
关键词： fasting plasma glucose,diabetic retinopathy,screening,HgA1c,lens autofluorescence,diabetes
更新于2025-09-23 15:22:29
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Employing Image Processing Techniques and Artificial Intelligence for Automated Eye Diagnosis Using Digital Eye Fundus Images
摘要： Blindness usually comes from two main causes, glaucoma and diabetes. Robust mass screening is performed for diagnosing, such as screening that requires a cost-effective method for glaucoma and diabetic retinopathy and integrates well with digital medical imaging, image processing, and administrative processes. For addressing all these issues, we propose a novel low-cost automated glaucoma and diabetic retinopathy diagnosis system, based on features extraction from digital eye fundus images. This paper proposes a diagnosis system for automated identification of healthy, glaucoma, and diabetic retinopathy. Using a combination of local binary pattern features, Gabor filter features, statistical features, and color features which are then fed to an artificial neural network and support vector machine classifiers. In this work, the classifier identifies healthy, glaucoma, and diabetic retinopathy images with an accuracy of 91.1%,92.9%, 92.9%, and 92.3% and sensitivity of 91.06%, 92.6%, 92.66%, and 91.73% and specificity of 89.83%, 91.26%, 91.96%, and 89.16% for ANN, and an accuracy of 90.0%,92.94%, 95.43%, and 97.92% and sensitivity of 89.34%, 93.26%, 95.72%, and 97.93% and specificity of 95.13%, 96.68%, 97.88%, and 99.05% for SVM, based on 5, 10, 15, and 31 number of selected features. The proposed system can detect glaucoma, diabetic retinopathy and normal cases with high accuracy and sensitivity using selected features, the performance of the system is high due to using of a huge fundus database.
关键词： and Classification,Diagnosis,Diabetic Retinopathy,Glaucoma,Eye Fundus
更新于2025-09-23 15:22:29
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The Prevalence and Risk Factors for Diabetic Retinopathy in Shiraz, Southern Iran
摘要： Globally, diabetic retinopathy (DR) is one of the leading causes of blindness, that diminishes quality of life. This study aimed to describe the prevalence of DR, and its associated risk factors. This cross-sectional study was carried out among 478 diabetic patients in a referral center in Fars province, Iran. The mean±standard deviation age of the participants was 56.64±12.45 years old and DR prevalence was 32.8%. In multivariable analysis, lower education levels (adjusted odds ratio [aOR], 0.43; 95% confidence interval [CI], 0.24 to 0.76), being overweight (aOR, 1.70; 95% CI, 1.02 to 2.83) or obese (aOR, 1.88; 95% CI, 1.09 to 3.26), diabetes duration of 10 to 20 years (aOR, 2.35; 95% CI, 1.48 to 3.73) and over 20 years (aOR, 5.63; 95% CI, 2.97 to 10.68), receiving insulin (aOR, 1.99; 95% CI, 1.27 to 3.10), and having chronic diseases (aOR, 1.71; 95% CI, 1.02 to 2.85) were significantly associated with DR. In conclusion, longer diabetes duration and obesity or having chronic diseases are strongly associated with DR suggesting that control of these risk factors may reduce both the prevalence and impact of retinopathy in Iran.
关键词： Diabetic retinopathy,Prevalence,Diabetes,Diabetes duration,Risk factors,Insulin
更新于2025-09-23 15:22:29
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Assessment of diabetic teleretinal imaging program at the Portland Department of Veterans Affairs Medical Center
摘要： We conducted a retrospective chart review of 200 diabetic patients who had teleretinal imaging performed between January 1, 2010, and January 1, 2011, at Portland Department of Veterans Affairs (VA) Medical Center outpatient clinics to assess the effectiveness of the diabetic teleretinal imaging program. Twenty patients (10%) had diabetic retinopathy. Ninety percent of the available teleretinal imaging studies were of adequate quality for interpretation. In accordance with local VA policy at that time, all teleretinal imaging patients should have been referred for a dilated retinal examination the following year. Image readers referred 97.5% of the patients to eye clinics for subsequent eye examinations, but the imagers scheduled appointments for only 80% of these patients. The redundancy rate, i.e., patients who had an eye examination within the past 6 mo, was 11%; the duplicate recall rate, i.e., patients who had a second teleretinal imaging performed within 1 yr of the eye examination, was 37%. Rates of timely diabetic eye examinations at clinics with teleretinal imaging programs, particularly when teleretinal imaging and eye clinics were colocated at the same community-based outpatient clinic, were higher than at those without a teleretinal imaging program. We concluded that the Portland VA Medical Center's teleretinal imaging program was successful in increasing the screening rate for diabetic retinopathy.
关键词： teleretinal imaging program,diabetes mellitus,dilated eye examination,diabetic retinal examination,primary care,diabetic retinopathy,outpatient clinic,screening,teleretinal imaging,telehealth
更新于2025-09-23 15:22:29
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Cone Photoreceptor Dysfunction in Early-Stage Diabetic Retinopathy: Association Between the Activation Phase of Cone Phototransduction and the Flicker Electroretinogram
摘要： PURPOSE. To define the nature and extent of cone photoreceptor abnormalities in diabetic individuals who have mild or no retinopathy by assessing the activation phase of cone phototransduction and the flicker ERG in these individuals. METHODS. Light-adapted single-flash and flicker ERGs were recorded from 20 diabetic individuals who have no clinically apparent retinopathy (NDR), 20 diabetic individuals who have mild nonproliferative diabetic retinopathy (NPDR), and 20 nondiabetic, age-equivalent controls. A-waves elicited by flashes of different retinal illuminance were fit with a delayed Gaussian model to derive Rmp3 (maximum amplitude of the massed photoreceptor response) and S (phototransduction sensitivity). Fundamental amplitude and phase of ERGs elicited by full-field sinusoidal flicker were obtained across a frequency range of 6 to 100 Hz. RESULTS. ANVOA indicated that both diabetic groups had significant S losses compared with the controls, whereas mean Rmp3 did not differ significantly among the groups. ANOVA also indicated significantly reduced flicker ERG amplitude for frequencies ≥56 Hz for both diabetic groups compared with the controls. Flicker ERG timing (phase) did not differ significantly among the groups. Log Rmp3 + log S was significantly correlated with the patients’ high-frequency (62.5 Hz) flicker ERG amplitude loss (r = 0.69, P < 0.001). CONCLUSIONS. The delayed Gaussian a-wave model is useful for characterizing abnormalities in the activation phase of cone phototransduction and can help explain flicker ERG abnormalities in early-stage diabetic retinopathy. Reduced cone sensitivity and attenuated high-frequency flicker ERGs provide evidence for impaired cone function in these individuals.
关键词： electroretinogram,diabetic retinopathy,flicker electroretinogram,photoreceptors,a-wave
更新于2025-09-23 15:22:29
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[Lecture Notes in Computational Vision and Biomechanics] Computer Aided Intervention and Diagnostics in Clinical and Medical Images Volume 31 || Segmentation of Type II Diabetic Patient’s Retinal Blood Vessel to Diagnose Diabetic Retinopathy
摘要： Diabetic Retinopathy is one of the ophthalmic reasons for visual deficiency. The favored fixate of consideration is on the estimation of deviation in the breadth of the retinal veins and the new vessel development. To witness the progressions, segmentation has to be made primarily. A framework to improve the quality of the segmentation result over pathological retinal images is proposed. The proposed method uses adaptive histogram equalizer for preprocessing, pulse coupled neural Network model for automatic feature vector generation and extraction of the retinal blood vessels. The test result represents that the proposed method is enhanced than other retinal competitive methods. The evaluation of the proposed approach is executed over standard public DRIVE, STARE, REVIEW, HRF, and DRIONS fundus image datasets. The proposed technique improves the segmentation results in terms of sensitivity, specificity, and accuracy.
关键词： Fundus image,Feature extraction,Diabetic Retinopathy,Retinal blood vessel,Medical imaging
更新于2025-09-23 15:22:29
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MicroRNA-9 inhibits retinal neovascularization in rats with diabetic retinopathy by targeting vascular endothelial growth factor A
摘要： Diabetic retinopathy (DR) is a leading cause of adult visual impairment and loss. This study aims to explore the effects of microRNA‐9 (miR‐9) on retinal neovascularization during DR by targeting the vascular endothelial growth factor A (VEGFA). DR rat models were successfully established. Retinal microvascular endothelial cells (RMECs) of DR rats were isolated and treated with miR‐9 mimic, miR‐9 inhibitor or small interfering RNA (siRNA)‐VEGFA. The expressions of miR‐9, VEGFA, and cluster of differentiation 31 (CD31) of the rats’ tissues and cells were examined. The targeting relationship between miR‐9 and VEGFA was testified. The tubule formation, the cell proliferation and the periodic distribution and apoptosis were evaluated after transfection. In the retinal tissues of DR rats, miR‐9 expression decreased while the expression of VEGFA and CD31 increased. Notably, miR‐9 targeted and inhibited VEGFA expression. In response to the treatment of miR‐9 mimic and siRNA‐VEGFA, a reduction was identified in CD31 expression, tubule formation, and proliferation of RMECs and cell ratio in the S phase, but an increase was observed in apoptosis rate of RMECs. The treatment of miR‐9 inhibitor reversed the manifestations. Our study demonstrated that miR‐9 could inhibit retinal neovascularization of DR and tubule formation, and promote apoptosis in RMECs by targeting VEGFA.
关键词： retinal microvascular endothelial cells,diabetic retinopathy,vascular endothelial growth factor A,microRNA‐9,retinal neovascularization
更新于2025-09-23 15:21:21
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Medicine in ophthalmology
摘要： Ophthalmology is often a branch of medicine that is viewed as minor in relation to other specialities. However, there are numerous ophthalmic manifestations of neurological, rheumatological and general medical conditions. Some of these are considered emergencies (see pages xx of this chapter), but often signs are found within the eye that lead to systemic diagnoses requiring further intervention.
关键词： papilloedema,optic neuropathy,Diabetic retinopathy,thyroid eye disease,uveitis,MRCP
更新于2025-09-23 15:21:21