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Clinical Practice and Cases in... Aug 2022We present the case of an older male with point-of-care-ultrasound (POCUS) imaging consistent with retinal detachment who was instead found by ophthalmology to have a...
CASE PRESENTATION
We present the case of an older male with point-of-care-ultrasound (POCUS) imaging consistent with retinal detachment who was instead found by ophthalmology to have a ruptured arterial microaneurysm with vitreous and preretinal hemorrhage. The patient later had complete resolution of his symptoms. We discuss this retinal detachment "mimic."
DISCUSSION
Preretinal hemorrhage is an uncommon condition that can be mistaken for ophthalmologic emergencies such as retinal detachment. The images and videos shown here add to the body of evidence that POCUS is useful in diagnosing pre-retinal hemorrhage but must be differ-entiated from retinal detachment. These images also emphasize the need for further research and application of POCUS for the identification of preretinal hemorrhage.
PubMed: 36049192
DOI: 10.5811/cpcem2022.4.55301 -
FEBS Letters Apr 2023Senile plaques are a pathological hallmark of Alzheimer's disease (AD), yet the mechanism underlying their generation remains unknown. Beta-amyloid peptide (Aβ) is a...
Senile plaques are a pathological hallmark of Alzheimer's disease (AD), yet the mechanism underlying their generation remains unknown. Beta-amyloid peptide (Aβ) is a major component of senile plaques. We analysed AD brain tissues with histochemistry, immunohistochemistry and fluorescence imaging to examine the neural, vascular or blood Aβ contribution to senile plaque development. We found little neural marker co-expression with plaque Aβ, while co-expression of blood markers, such as Haemin and ApoE, was abundant. The plaque cores were structured with vascular and glial proteins outside and blood metabolites inside, co-localizing with a characteristic of Hoechst staining-independent blue autofluorescence. Erythrocyte-interacting Aβ is linked to coagulation, elevated calcium and blue autofluorescence, and it is associated with intravascular haemolysis, atherosclerosis, cerebral amyloid angiopathy, microaneurysm, and often with Cathepsin D co-expression. We identified microaneurysms as major sites of amyloid formation. Our data suggest that senile plaques arise from Aβ- and Cathepsin D-enriched mixtures leaking out during intravascular haemolysis and microaneurysm rupture.
Topics: Humans; Alzheimer Disease; Plaque, Amyloid; Microaneurysm; Cathepsin D; Hemolysis; Amyloid beta-Peptides; Brain
PubMed: 36448495
DOI: 10.1002/1873-3468.14549 -
Ophthalmology Nov 2019To investigate the relationship between the diabetic retinopathy (DR) severity and quantitative ultra-widefield angiographic metrics, including leakage index, ischemic...
PURPOSE
To investigate the relationship between the diabetic retinopathy (DR) severity and quantitative ultra-widefield angiographic metrics, including leakage index, ischemic index, and microaneurysm count.
DESIGN
Retrospective image analysis study.
METHODS
Eyes with DR that had undergone ultra-widefield fluorescein angiography (UWFA) with associated color photography were identified. All eyes were laser-naive and had not received any intravitreal pharmacotherapy within 6 months of UWFA. Each eye was graded for DR severity. Quantitative angiographic parameters were evaluated with a semiautomated analysis platform with expert reader correction, as needed. Angiographic parameters included panretinal leakage index, ischemic index, and microaneurysm count. Clinical characteristics analyzed included age, gender, race, hemoglobin A1C level, hypertension, systolic blood pressure, diastolic blood pressure, and smoking history.
MAIN OUTCOME MEASURES
Association of DR severity with panretinal leakage index, ischemic index, and microaneurysm count.
RESULTS
Three hundred thirty-nine eyes were included with mean age of 62±13 years. Forty-two percent of eyes were from women and 57.5% were from men. Distribution of DR severity was as follows: mild NPDR in 11.2%, moderate NPDR in 23.9%, severe NPDR in 40.1%, and PDR with 24.8%. Panretinal leakage index [mild NPDR (mean = 0.51%), moderate NPDR mean = 1.20%, severe NPDR (mean = 2.75%), and PDR (mean = 5.84%); P<2×10], panretinal ischemic index [mild NPDR (mean = 0.95%, moderate NPDR (mean = 1.37%), severe NPDR (mean = 2.80%), and PDR (mean = 9.53%); P<2×10], and panretinal microaneurysm count [mild NPDR (mean = 36), moderate NPDR (mean = 129), severe NPDR (mean = 203), and PDR (mean = 254); P<5×10] were strongly associated with DR severity. Multivariate analysis demonstrated that ischemic index and leakage index were the parameters associated most strongly with level of DR severity.
CONCLUSIONS
Panretinal leakage index, panretinal ischemic index, and panretinal microaneurysm count are associated with DR severity. Additional research is needed to understand the clinical implications of these parameters related to progression risk, prognosis, and implications for therapeutic response.
Topics: Adult; Aged; Blood Pressure; Capillary Permeability; Diabetic Retinopathy; Female; Fluorescein Angiography; Glycated Hemoglobin; Humans; Hypertension; Ischemia; Male; Microaneurysm; Middle Aged; Retinal Vessels; Retrospective Studies; Severity of Illness Index; Smoking; Visual Acuity
PubMed: 31383482
DOI: 10.1016/j.ophtha.2019.05.034 -
Translational Vision Science &... May 2024To identify progression of nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes by combining optical coherence tomography angiography (OCTA)...
PURPOSE
To identify progression of nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes by combining optical coherence tomography angiography (OCTA) metrics and color fundus photography (CFP) images.
METHODS
This study was a post hoc analysis of a prospective longitudinal cohort study (CORDIS, NCT03696810) with 2-year duration. This study enrolled 122 eyes. Ophthalmological examinations included OCTA and CFP. OCTA metrics included skeletonized vessel density (SVD) and perfusion density (PD) at the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Microaneurysm turnover analysis and Early Treatment Diabetic Retinopathy Study (ETDRS) grading for diabetic retinopathy (DR) severity assessment were performed on 7-field CFP.
RESULTS
Eyes graded as ETDRS level 20 showed significant capillary nonperfusion predominantly in the inner ring area in the SCP (P < 0.001), whereas eyes graded as ETDRS level 35 and ETDRS levels 43 and 47 showed significant capillary nonperfusion in both the SCP and DCP in both inner and outer rings (P < 0.001). When evaluating rates of progression in capillary nonperfusion for the 2-year period of follow-up, changes were found predominantly in the DCP for SVD and PD and were better identified in the outer ring area. Microaneurysm turnover contributes to the characterization of NPDR progression by discriminating ETDRS level 35 from ETDRS levels 43 and 47 (P < 0.001), which could not be achieved using only OCTA metrics.
CONCLUSIONS
Patterns of progression of NPDR can be identified combining OCTA examinations of the superficial and deep retinal capillary plexi of central retina and determination of microaneurysm turnover from fundus photographs.
TRANSLATIONAL RELEVANCE
Our study reports results from a registered clinical trial that advances understanding of disease progression in NPDR.
Topics: Humans; Diabetic Retinopathy; Disease Progression; Male; Female; Middle Aged; Tomography, Optical Coherence; Prospective Studies; Retinal Vessels; Aged; Fluorescein Angiography; Diabetes Mellitus, Type 2; Photography
PubMed: 38780953
DOI: 10.1167/tvst.13.5.22 -
Sensors (Basel, Switzerland) Jan 2022In diabetic retinopathy (DR), the early signs that may lead the eyesight towards complete vision loss are considered as microaneurysms (MAs). The shape of these MAs is...
In diabetic retinopathy (DR), the early signs that may lead the eyesight towards complete vision loss are considered as microaneurysms (MAs). The shape of these MAs is almost circular, and they have a darkish color and are tiny in size, which means they may be missed by manual analysis of ophthalmologists. In this case, accurate early detection of microaneurysms is helpful to cure DR before non-reversible blindness. In the proposed method, early detection of MAs is performed using a hybrid feature embedding approach of pre-trained CNN models, named as VGG-19 and Inception-v3. The performance of the proposed approach was evaluated using publicly available datasets, namely "E-Ophtha" and "DIARETDB1", and achieved 96% and 94% classification accuracy, respectively. Furthermore, the developed approach outperformed the state-of-the-art approaches in terms of sensitivity and specificity for microaneurysms detection.
Topics: Algorithms; Deep Learning; Diabetic Retinopathy; Fundus Oculi; Humans; Microaneurysm; Sensitivity and Specificity
PubMed: 35062506
DOI: 10.3390/s22020542 -
Ophthalmologica. Journal International... 2020In the last decades, significant changes have been taking place regarding the pathogenesis of diabetic retinopathy (DR) and the complex mechanisms that eventually lead... (Review)
Review
In the last decades, significant changes have been taking place regarding the pathogenesis of diabetic retinopathy (DR) and the complex mechanisms that eventually lead to the various manifestations of the disease, including diabetic macular edema (DME). DR was first considered a pure microvascular disease, due to the evident capillary structural changes (microaneurysms), fluid extravasation, and lipid exudation. With the advent of fundus fluorescein angiography, the concept of ischemia and the correlation between peripheral nonperfusion and neovascularization has been introduced, which was eventually followed by the advent of new therapeutic strategies, such as peripheral photocoagulation. Nowadays, thanks to more advanced imaging techniques, namely optical coherence tomography (OCT), OCT angiography, and wide-field imaging (imaging up to 200° of the retina in a single shot), it became clear that other elements participate in the occurrence of DR and DME, including inflammation and neurodegeneration. In the future, integration of standard investigations with new diagnostic devices would allow the prompt recognition of DR even before clinical signs of the disease are ophthalmoscopically evident, and the development of personalized treatment for both retinopathy and DME will be available.
Topics: Diabetic Retinopathy; Fluorescein Angiography; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Tomography, Optical Coherence
PubMed: 32015239
DOI: 10.1159/000506312 -
Bioengineering (Basel, Switzerland) Dec 2023Diabetic retinopathy (DR) is a microvascular complication of diabetes. Microaneurysms (MAs) are often observed in the retinal vessels of diabetic patients and represent...
Diabetic retinopathy (DR) is a microvascular complication of diabetes. Microaneurysms (MAs) are often observed in the retinal vessels of diabetic patients and represent one of the earliest signs of DR. Accurate and efficient detection of MAs is crucial for the diagnosis of DR. In this study, an automatic model (MA-YOLO) is proposed for MA detection in fluorescein angiography (FFA) images. To obtain detailed features and improve the discriminability of MAs in FFA images, SwinIR was utilized to reconstruct super-resolution images. To solve the problems of missed detection of small features and feature information loss, an MA detection layer was added between the neck and the head sections of YOLOv8. To enhance the generalization ability of the MA-YOLO model, transfer learning was conducted between high-resolution images and low-resolution images. To avoid excessive penalization due to geometric factors and address sample distribution imbalance, the loss function was optimized by taking the Wise-IoU loss as a bounding box regression loss. The performance of the MA-YOLO model in MA detection was compared with that of other state-of-the-art models, including SSD, RetinaNet, YOLOv5, YOLOX, and YOLOv7. The results showed that the MA-YOLO model had the best performance in MA detection, as shown by its optimal metrics, including recall, precision, F1 score, and AP, which were 88.23%, 97.98%, 92.85%, and 94.62%, respectively. Collectively, the proposed MA-YOLO model is suitable for the automatic detection of MAs in FFA images, which can assist ophthalmologists in the diagnosis of the progression of DR.
PubMed: 38135996
DOI: 10.3390/bioengineering10121405 -
Proceedings of the National Academy of... Mar 2021Understanding the mechanics of blood flow is necessary for developing insights into mechanisms of physiology and vascular diseases in microcirculation. Given the...
Understanding the mechanics of blood flow is necessary for developing insights into mechanisms of physiology and vascular diseases in microcirculation. Given the limitations of technologies available for assessing in vivo flow fields, in vitro methods based on traditional microfluidic platforms have been developed to mimic physiological conditions. However, existing methods lack the capability to provide accurate assessment of these flow fields, particularly in vessels with complex geometries. Conventional approaches to quantify flow fields rely either on analyzing only visual images or on enforcing underlying physics without considering visualization data, which could compromise accuracy of predictions. Here, we present artificial-intelligence velocimetry (AIV) to quantify velocity and stress fields of blood flow by integrating the imaging data with underlying physics using physics-informed neural networks. We demonstrate the capability of AIV by quantifying hemodynamics in microchannels designed to mimic saccular-shaped microaneurysms (microaneurysm-on-a-chip, or MAOAC), which signify common manifestations of diabetic retinopathy, a leading cause of vision loss from blood-vessel damage in the retina in diabetic patients. We show that AIV can, without any a priori knowledge of the inlet and outlet boundary conditions, infer the two-dimensional (2D) flow fields from a sequence of 2D images of blood flow in MAOAC, but also can infer three-dimensional (3D) flow fields using only 2D images, thanks to the encoded physics laws. AIV provides a unique paradigm that seamlessly integrates images, experimental data, and underlying physics using neural networks to automatically analyze experimental data and infer key hemodynamic indicators that assess vascular injury.
Topics: Artificial Intelligence; Blood Flow Velocity; Computer Simulation; Diabetic Retinopathy; Hemodynamics; Humans; Imaging, Three-Dimensional; Lab-On-A-Chip Devices; Microaneurysm; Microfluidic Analytical Techniques; Regional Blood Flow; Retinal Vessels; Rheology
PubMed: 33762307
DOI: 10.1073/pnas.2100697118 -
Journal of Digital Imaging Apr 2018Automated microaneurysm (MA) detection is still an open challenge due to its small size and similarity with blood vessels. In this paper, we present a novel method which...
Automated microaneurysm (MA) detection is still an open challenge due to its small size and similarity with blood vessels. In this paper, we present a novel method which is simple, efficient, and real-time for segmenting and detecting MA in color fundus images (CFI). To do this, a novel set of features based on statistics of geometrical properties of connected regions, that can easily discriminate lesion and non-lesion pixels are used. For large-scale evaluation proposed method is validated on DIARETDB1, ROC, STARE, and MESSIDOR dataset. It proves robust with respect to different image characteristics and camera settings. The best performance was achieved on per-image evaluation on DIARETDB1 dataset with sensitivity of 88.09 at 92.65% specificity which is quite encouraging for clinical use.
Topics: Databases, Factual; Diabetic Retinopathy; Diagnostic Techniques, Ophthalmological; Fundus Oculi; Humans; Image Interpretation, Computer-Assisted; Microaneurysm; Sensitivity and Specificity
PubMed: 28785874
DOI: 10.1007/s10278-017-0008-0 -
Medicina (Kaunas, Lithuania) Feb 2023This study aims to elucidate the role of microaneurysms (MAs) in the pathogenesis and treatment of diabetic retinopathy (DR) and diabetic macular edema (DME), the major... (Review)
Review
This study aims to elucidate the role of microaneurysms (MAs) in the pathogenesis and treatment of diabetic retinopathy (DR) and diabetic macular edema (DME), the major causes of acquired visual impairment. We synthesized the relevance of findings on the clinical characteristics, pathogenesis, and etiology of MAs in DR and DME and their role in anti-vascular endothelial growth factor (VEGF) therapy. MAs, a characteristic feature in DR and DME, can be detected by fluorescein angiography, optical coherence tomography (OCT) and OCT angiography. These instrumental analyses demonstrated a geographic and functional association between MA and ischemic areas. MA turnover, the production and loss of MA, reflects the activity of DME and DR. Several cytokines are involved in the pathogenesis of MAs, which is characterized by pericyte loss and endothelial cell proliferation in a VEGF-dependent or -independent manner. Ischemia and MAs localized in the deep retinal layers are characteristic of refractory DME cases. Even in the current anti-VEGF era, laser photocoagulation targeting MAs in the focal residual edema is still an effective therapeutic tool, but it is necessary to be creative in accurately identifying the location of MAs and performing highly precise and minimally invasive coagulation. MAs play a distinctive and important role in the pathogenesis of the onset, progression of DR and DME, and response to anti-VEGF treatment. Further research on MA is significant not only for understanding the pathogenesis of DME but also for improving the effectiveness of treatment.
Topics: Humans; Diabetic Retinopathy; Macular Edema; Microaneurysm; Retina; Fluorescein Angiography; Tomography, Optical Coherence; Diabetes Mellitus
PubMed: 36984436
DOI: 10.3390/medicina59030435