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En Face Optical Coherence Tomography Imaging of the Photoreceptor Layers in Hydroxychloroquine Retinopathy
摘要： Objective: To investigate the application of en face optical coherence tomography (OCT) imaging in eyes with hydroxychloroquine (HCQ) retinopathy. Design: Retrospective case series Methods: Setting: Institutional Patient Population: Sixty-two eyes of 31 Asian patients with HCQ retinopathy. Observation Procedures: Macular volume scanning using swept-source OCT was performed in 6 × 6 and 9 × 9 mm areas centered on the fovea. Segmentation of the photoreceptor layers was automatically performed between the inner border of the ellipsoid zone and that of the retinal pigment epithelium-Bruch’s membrane complex to obtain en face OCT images. Findings from the en face images were qualitatively and quantitatively evaluated; they were analyzed and correlated with the fundus autofluorescence and visual field findings. Main Outcome Measures: En face OCT findings Results: All eyes with HCQ retinopathy had a beaten-bronze appearance in the areas with photoreceptor defects, whereas those with intact photoreceptors had areas with smooth surfaces, which were occasionally demarcated by hyporeflective margins, on the en face OCT images. The presence and extent of the retinopathy could be quickly determined using the images. They also provided quantitative information on the progression based on the areas of intact photoreceptors compared over several visits. Furthermore, the area of central intact photoreceptors significantly correlated with the mean deviation, pattern standard deviation, and visual field index of 30-2 visual field examinations (all P < .001). Conclusions: En face OCT may be useful for visualizing the presence and extent of HCQ retinopathy and its progression. The area of central intact photoreceptors measured on en face OCT images showed a significant association with functional visual field defects. This imaging may be a helpful adjunct for screening and follow-up examinations of HCQ retinopathy.
关键词： screening,en face optical coherence tomography,photoreceptor layers,progression,hydroxychloroquine retinopathy
更新于2025-09-09 09:28:46
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Association between microRNAs expression and signaling pathways of inflammatory markers in diabetic retinopathy
摘要： Diabetic retinopathy is one of the common and serious microvascular complications of diabetes mellitus, as hyperglycemia has metabolic effects on the retina. Hyperglycemia induces increased oxidative stress, which stimulates inflammation pathways and promotes vascular dysfunction of the retina that leads to increased capillary permeability and vascular leakage. One of the main factors involving diabetic retinopathy is the inflammation signaling pathways. In contemporary times, microRNAs (miRNAs) are identified as functional biomarkers for early detection and treatment of numerous diseases specifically diabetic retinopathy. MiRNAs can modulate gene expression through regulation of transcriptional and posttranscriptional of target genes. With that, miRNAs can regulate almost every cellular and developmental process, including the regulation of instinct immune responses and inflammation. The aim of this study is to investigate the role of miRNAs in inflammation pathways and the pathogenesis of diabetic retinopathy.
关键词： miRNAs,inflammation pathway,diabetic retinopathy
更新于2025-09-09 09:28:46
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[IEEE 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) - Atlanta, GA (2017.10.21-2017.10.28)] 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) - Automated Optic Nerve Head Detection Based on Different Retinal Vasculature Segmentation Methods and Mathematical Morphology
摘要： Computer vision and image processing techniques provide important assistance to physicians and relieve their work load in different tasks. In particular, identifying objects of interest such as lesions and anatomical structures from the image is a challenging and iterative process that can be done by using computer vision and image processing approaches in a successful manner. Optic Nerve Head (ONH) detection is a crucial step in retinal image analysis algorithms. The goal of ONH detection is to ?nd and detect other retinal landmarks and lesions and their corresponding diameters, to use as a length reference to measure objects in the retina. The objective of this study is to apply three retinal vessel segmentation methods, Laplacian-of-Gaussian edge detector, Canny edge detector, and Matched ?lter edge detector for detection of the ONH either in the normal fundus images or in the presence of retinal lesions (e.g. diabetic retinopathy). The steps for the segmentation are as following: 1) Smoothing: suppress as much noise as possible, without destroying the true edges, 2) Enhancement: apply a ?lter to enhance the quality of the edges in the image (sharpening), 3) Detection: determine which edge pixels should be discarded as noise and which should be retained by thresholding the edge strength and edge size, 4) Localization: determine the exact location of an edge by edge thinning or linking. To evaluate the accuracy of our proposed method, we compare the output of our proposed method with the ground truth data that collected by ophthalmologists on retinal images belonging to a test set of 120 images. As shown in the results section, by using the Laplacian-of-Gaussian vessel segmentation, our automated algorithm ?nds 18 ONHs in true location for 20 color images in the CHASE-DB database and all images in the DRIVE database. For the Canny vessel segmentation, our automated algorithm ?nds 16 ONHs in true location for 20 images in the CHASE-DB database and 32 out of 40 images in the DRIVE database. And lastly, using matched ?lter in the vessel segmentation, our algorithm ?nds 19 ONHs in true location for 20 images in CHASE-DB database and all images in the DRIVE.
关键词： Laplacian-of-Gaussian edge detector,Diabetic retinopathy,Match ?lter,image processing,Optic Nerve Head,Canny edge detector,retinal blood vessel
更新于2025-09-09 09:28:46
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Patients with Advanced Diabetic Retinopathy’s Understanding of Diabetes Mellitus and Their Diabetic Eye Disease: A survey of 100 patients currently undergoing treatment for Diabetic Retinopathy in a Large Retinal Practice
摘要： Objective: To better understand what patients with advanced diabetic retinopathy understand about their DED and treatment, control of their diabetes, and risk factors for disease progression, and to assess which areas clinicians may want to target for education to increase patient understanding. Methods: 100 consecutive patients with at least 5 previous visits to a retinal clinic were surveyed to better understand patients’ understanding of diabetes mellitus (DM), diabetic eye disease (DED), and the treatments they were receiving for DM and their DED. Demographic information (age, gender, educational status, ethnicity, language, duration and treatments for DM) was collected, along with information about treatments and understanding of risk and modifiable factors about DM. Data was verified against the chart. Results: 100 surveys were completed; 97% of patients said they “understand DM”. 61% of patients were 60 years or older, and half of the patients had done some post-secondary educational training. The ethnic breakdown included 27% Caucasian and 38% Hispanic. Fasting blood glucose (FBG) was known in 89% of patients and when asked the range of FBG: 6% did not know; 17% had FBG as >160 mg/dl; and 35% had a FBG of <130 mg/dl. Regarding controlling their DM, 74% of patients did not identify exercise and 33% did not identify dietary habit as important in control. 95% identified blood pressure (BP) as important to monitor. 39% were unable to identify their current BP range, 31% identified their systolic BP as ≥ 130mmHg, and 7% described it as usually >150mmHg. Patients were asked to identify DM related ocular complications: 23% said bleeding; 7% said diabetic macular edema; and 73% said blindness or visual loss. As patient age increased, the ability to correctly identifying current treatments, and knowledge of hemoglobin A1C (HbA1C), decreased. Ability to correctly identify HbA1C increased with increasing education. Conclusions: This survey shows patient misunderstanding in how DM is treated, risk factors for DM, and how monitoring should be done. Emphasis is likely needed in diet modification and exercise for control of DM. Patients may be at risk for poor understanding of DM care/treatment (particularly those with lower educational achievement, or more elderly). Additional resources may need to be developed for sub-sets of patients.
关键词： Diabetic eye disease,Patient understanding,Diabetes mellitus,Risk factors,Diabetic retinopathy,Hemoglobin A1C
更新于2025-09-09 09:28:46
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[IEEE 2018 24th International Conference on Pattern Recognition (ICPR) - Beijing, China (2018.8.20-2018.8.24)] 2018 24th International Conference on Pattern Recognition (ICPR) - Early Diagnosis of Diabetic Retinopathy in OCTA Images Based on Local Analysis of Retinal Blood Vessels and Foveal Avascular Zone
摘要： This paper introduces a diagnosis system for detecting early signs of diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA) images. We developed a segmentation technique that was able to extract blood vessels from both retinal superficial and deep maps. It is based on a higher order joint Markov-Gibbs random field (MGRF) model, which combines both current and spatial appearance information of retinal blood vessels. To be able to train/test a support vector machine (SVM) classifier, three local features were extracted from the segmented images. These extracted features are the density and appearance of the retinal blood vessels in addition to the distance map of the foveal avascular zone (FAZ). Then, we used SVM with linear kernel to distinguish sub-clinical DR patients from normal cases. By using 105 subjects, the presented computer-aided diagnosis (CAD) system demonstrated an overall accuracy (ACC) of 97.3% and a Dice similarity coefficient (DSC) of 97.9%.
关键词： Markov-Gibbs random field,support vector machine,diabetic retinopathy,optical coherence tomography angiography,computer-aided diagnosis
更新于2025-09-09 09:28:46
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High-Fat Diet–Induced Retinal Dysfunction
摘要： PURPOSE. The purpose of this study was to investigate the impact of obesity-induced prediabetes/early diabetes on the retina to provide new evidence on the pathogenesis of type 2 diabetes–associated diabetic retinopathy (DR). METHODS. A high-fat diet (HFD)–induced obesity mouse model (male C57BL/6J) was used in this study. At the end of the 12-week HFD feeding regimen, mice were evaluated for glucose and insulin tolerance, and retinal light responses were recorded by electroretinogram (ERG). Western immunoblot and immunohistochemical staining were used to determine changes in elements regulating calcium homeostasis between HFD and control retinas, as well as unstained human retinal sections from DR patients and age-appropriate controls. RESULTS. Compared to the control, the scotopic and photopic ERGs from HFD mice were decreased. There were signi?cant decreases in molecules related to cell signaling, calcium homeostasis, and glucose metabolism from HFD retinas, including phosphorylated protein kinase B (pAKT), glucose transporter 4, L-type voltage-gated calcium channel (L-VGCC), and plasma membrane calcium ATPase (PMCA). Similar changes for pAKT, PMCA, and L-VGCC were also observed in human retinal sections from DR patients. CONCLUSIONS. Obesity-induced hyperglycemic and prediabetic/early diabetic conditions caused detrimental impacts on retinal light sensitivities and health. The decrease of the ERG components in early diabetes re?ects the decreased neuronal activity of retinal light responses, which may be caused by a decrease in neuronal calcium signaling. Since PI3K-AKT is important in regulating calcium homeostasis and neural survival, maintaining proper PI3K-AKT signaling in early diabetes or at the prediabetic stage might be a new strategy for DR prevention.
关键词： obesity,type 2 diabetes,retinopathy,high-fat diet,calcium homeostasis
更新于2025-09-09 09:28:46
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Retinal Neurodegeneration in Diabetic Patients Without Diabetic Retinopathy
摘要： PURPOSE. To compare the thickness of all retinal layers between a nondiabetic group and diabetic patients without diabetic retinopathy (DR). METHODS. Cross-sectional study, in which all subjects underwent an ophthalmic examination including optical coherence tomography. After automatic retinal segmentation, each retinal layer thickness (eight separate layers and overall thickness) was calculated in all nine Early Treatment Diabetic Retinopathy Study (ETDRS) areas. The choroidal thickness (CT) also was measured at five locations. Generalized additive regression models were used to analyze the data. RESULTS. A total of 175 patients were recruited, 50 nondiabetic subjects and 125 diabetic patients without DR, stratified into three groups according to diabetes duration: group I (<5 years, n = 55), group II (5–10 years, n = 39), and group III (>10 years, n = 31). Overall, groups I and III of diabetic patients had a decrease in the photoreceptor layer (PR) thickness, when compared with the nondiabetic subjects in six ETDRS areas (P < 0.0007). Patients with more recent diagnosis (group I) had thinner PR than those with moderate duration (group II). Interestingly, patients with longer known disease (group III) had the thinnest PR values. There were no overall differences in the remaining retinal parameters. CONCLUSIONS. Retinal thickness profile is not linear throughout disease duration. Even in the absence of funduscopic disease, PR layer in diabetic patients seems to differ from nondiabetic subjects, thus suggesting that some form of neurodegeneration may take place before clinical signs of vascular problems arise.
关键词： neurodegeneration,retinal layers,diabetic retinopathy,optical coherence tomography
更新于2025-09-09 09:28:46
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Screening Examination of Premature Infants for Retinopathy of Prematurity
摘要： This policy statement revises a previous statement on screening of preterm infants for retinopathy of prematurity (ROP) that was published in 2013. ROP is a pathologic process that occurs in immature retinal tissue and can progress to a tractional retinal detachment, which may then result in visual loss or blindness. For more than 3 decades, treatment of severe ROP that markedly decreases the incidence of this poor visual outcome has been available. However, severe, treatment-requiring ROP must be diagnosed in a timely fashion to be treated effectively. The sequential nature of ROP requires that infants who are at-risk and preterm be examined at proper times and intervals to detect the changes of ROP before they become destructive. This statement presents the attributes of an effective program to detect and treat ROP, including the timing of initial and follow-up examinations.
关键词： retinopathy of prematurity,ROP,preterm infants,screening,blindness
更新于2025-09-09 09:28:46
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Expanding the role of medical retina virtual clinics using multimodal ultra-widefield and optical coherence tomography imaging
摘要： Background: An increasingly elderly population with a corresponding increase in ophthalmic conditions has led to increased pressure on hospital eye services (HES). In this study, we evaluated the use of a medical retina virtual clinic (MRVC), which has expanded into assessing all new medical retina referrals, where the need for urgent treatment was not clear. Methods: Retrospective analysis of all new patients who were seen in the MRVC between April 2016 and May 2018. Pro forma sheets were used in the MRVC to record the patient history, visual acuity, and type of imaging required. Two consultants reviewed the completed pro formas and images and provided a final diagnosis and management plan. These results and reasons for face-to-face (F2F) clinic appointment requests were analyzed. Results: Six hundred ten new referrals were enrolled in the virtual clinic. The most common diagnosis was diabetic eye disease (59.9%). In the virtual clinic 44.1% were followed up, 28.1% were discharged, and 27.8% were booked an F2F clinic appointment (urgent/routine). The main reason for F2F clinic was to offer treatment. Urgent F2F appointments took place on average 11.9 days after virtual clinic attendance. In only two cases was the image quality felt to be inadequate to assess the retina. Conclusions: MRVC is an effective way of triaging medical retina referrals to allow those patients needing treatment to be seen promptly in the medical retinal service. The use of multimodal ultra-widefield and optical coherence tomography imaging allows assessment of a wide range of retinal pathologies and is a promising solution to alleviate the burden on HES.
关键词： teleophthalmology,diabetic retinopathy,optical coherence tomography,macular degeneration,choroidal naevus,virtual clinic
更新于2025-09-09 09:28:46
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Retrobulbar blood flow changes in eyes with diabetic retinopathy a 10 year follow up study
摘要： Purpose: We sought to assess long-term changes in the flow parameters of retrobulbar vessels in diabetic patients. Methods: The retrobulbar circulation of 138 eyes was evaluated between 1994 and 1995 and 36 eyes were reevaluated between 2004 and 2008 (study group). They were divided into four groups: eyes of diabetic patients without diabetic retinopathy (DR), eyes with nonproliferative DR, eyes with proliferative DR, and eyes of nondiabetic patients (controls). Color Doppler imaging was used to assess the flow velocities in the major retrobulbar vessels. The resistive index (RI) was calculated and compared among the groups and between the two time periods. Results: RI values of the central retinal artery and posterior ciliary artery had increased in the two non-DR groups and in the nonproliferative DR group, with a surprising decrease measured in eyes with proliferative DR (P= nonsignificant [NS]). Combining the nonproliferative DR and proliferative DR groups resulted in a milder increase of the RI of the posterior ciliary artery (P= NS) and the central retinal artery (P=0.02) in the DR group compared to the other groups. Conclusion: Our results demonstrate that an increase of the resistance in the retrobulbar vessels, as a part of DR, can lessen over time and may even be reversed.
关键词： color Doppler imaging,retrobulbar blood flow,diabetic retinopathy
更新于2025-09-09 09:28:46