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Clinical Ophthalmology (Auckland, N.Z.) 2023To evaluate the agreement between conventional fundus photography (CFP) and multicolor fundus imaging (MFI) for the detection of lesions of diabetic retinopathy (DR) and...
PURPOSE
To evaluate the agreement between conventional fundus photography (CFP) and multicolor fundus imaging (MFI) for the detection of lesions of diabetic retinopathy (DR) and retinal vein occlusion (RVO).
METHODS
Cross-sectional analysis of eyes with DR or RVO who underwent CFP and MFI. All images were independently analyzed by two observers (O1 and O2), and the evaluated lesions were classified as "present" or "absent". Then, a paired comparison between both exams of the same eye was performed, to assess which made it easier to detect the lesions.
RESULTS
Considering DR, the agreement was substantial for cotton wool spots and photocoagulation scars for both observers (O1: =0.75 and =0.67; O2: =0.71 and =0.64, respectively) and for hard exudates for O1 (=0.80). These lesions were detected more frequently on MFI. Regarding RVO, the agreement was considered substantial for venous sheathing by O1 (=0.64) and moderate for optociliary shunts by O2 (=0.60). Optociliary shunts were detected more frequently in CPF by both observers and venous sheathing on MFI by O1. For microaneurysms, retinal hemorrhages, retinal neovascularization, and proliferative membranes, in DR, and retinal hemorrhages, venous engorgement, and retinal neovascularization in RVO, the agreement was almost perfect (>0.82). In the paired analysis, both observers considered that, in DR, microaneurysms and retinal hemorrhages were easier to detect on CFP and that retinal neovascularization, cotton wool spots, and photocoagulation scars were easier to identify on MFI. Regarding RVO, optocilliary shunts were easier to identify on CFP and venous engorgement on MFI.
CONCLUSION
The agreement of MFI and CFP was substantial to almost perfect for most lesions. MFI seems better to detect cotton wool spots and photocoagulations scars in DR and venous sheathing in RVO. Optocilliary shunts seem easier to detect on CFP.
PubMed: 37641738
DOI: 10.2147/OPTH.S414603 -
Health Information Science and Systems Dec 2023Medical image segmentation is a challenging task due to the high variation in shape, size and position of infections or lesions in medical images. It is necessary to...
Medical image segmentation is a challenging task due to the high variation in shape, size and position of infections or lesions in medical images. It is necessary to construct multi-scale representations to capture image contents from different scales. However, it is still challenging for U-Net with a simple skip connection to model the global multi-scale context. To overcome it, we proposed a dense skip-connection with cross co-attention in U-Net to solve the semantic gaps for an accurate automatic medical image segmentation. We name our method MCA-UNet, which enjoys two benefits: (1) it has a strong ability to model the multi-scale features, and (2) it jointly explores the spatial and channel attentions. The experimental results on the COVID-19 and IDRiD datasets suggest that our MCA-UNet produces more precise segmentation performance for the consolidation, ground-glass opacity (GGO), microaneurysms (MA) and hard exudates (EX). The source code of this work will be released via https://github.com/McGregorWwww/MCA-UNet/.
PubMed: 36721640
DOI: 10.1007/s13755-022-00209-4 -
Medicina (Kaunas, Lithuania) Jan 2024: The role and the levels of ghrelin in diabetes-induced retinal damage have not yet been explored. The present study aimed to measure the serum levels of total ghrelin...
: The role and the levels of ghrelin in diabetes-induced retinal damage have not yet been explored. The present study aimed to measure the serum levels of total ghrelin (TG), and its acylated (AG) and des-acylated (DAG) forms in patients with the two stages of diabetic retinopathy (DR), non-proliferative (NPDR) and proliferative (PDR). Moreover, the correlation between serum ghrelin and neutrophil elastase (NE) levels was investigated. : The serum markers were determined via enzyme-linked immunosorbent assays in 12 non-diabetic subjects (CTRL), 15 diabetic patients without DR (Diabetic), 15 patients with NPDR, and 15 patients with PDR. : TG and AG serum levels were significantly decreased in Diabetic (respectively, < 0.05 and < 0.01 vs. CTRL), NPDR ( < 0.01 vs. Diabetic), and in PDR patients ( < 0.01 vs. NPDR). AG serum levels were inversely associated with DR abnormalities (microhemorrhages, microaneurysms, and exudates) progression (r = -0.83, < 0.01), serum neutrophil percentage (r = -0.74, < 0.01), and serum NE levels (r = -0.73, < 0.01). The latter were significantly increased in the Diabetic ( < 0.05 vs. CTRL), NPDR ( < 0.01 vs. Diabetic), and PDR ( < 0.01 vs. PDR) groups. : The two DR stages were characterized by decreased AG and increased NE levels. In particular, serum AG levels were lower in PDR compared to NPDR patients, and serum NE levels were higher in the PDR vs. the NPDR group. Together with the greater presence of retinal abnormalities, this could underline a distinctive role of AG in PDR compared to NPDR.
Topics: Humans; Leukocyte Elastase; Diabetic Retinopathy; Ghrelin; Enzyme-Linked Immunosorbent Assay; Exudates and Transudates; Diabetes Mellitus
PubMed: 38256379
DOI: 10.3390/medicina60010118 -
International Journal of Retina and... Oct 2023This study aimed to develop a deep learning (DL) algorithm that enhances the quality of a single-frame enface OCTA scan to make it comparable to 4-frame averaged scan...
BACKGROUND
This study aimed to develop a deep learning (DL) algorithm that enhances the quality of a single-frame enface OCTA scan to make it comparable to 4-frame averaged scan without the need for the repeated acquisitions required for averaging.
METHODS
Each of the healthy eyes and eyes from diabetic subjects that were prospectively enrolled in this cross-sectional study underwent four repeated 6 × 6 mm macular scans (PLEX Elite 9000 SS-OCT), and the repeated scans of each eye were co-registered to produce 4-frame averages. This prospective dataset of original (single-frame) enface scans and their corresponding averaged scans was divided into a training dataset and a validation dataset. In the training dataset, a DL algorithm (named pseudoaveraging) was trained using original scans as input and 4-frame averages as target. In the validation dataset, the pseudoaveraging algorithm was applied to single-frame scans to produce pseudoaveraged scans, and the single-frame and its corresponding averaged and pseudoaveraged scans were all qualitatively compared. In a separate retrospectively collected dataset of single-frame scans from eyes of diabetic subjects, the DL algorithm was applied, and the produced pseudoaveraged scan was qualitatively compared against its corresponding original.
RESULTS
This study included 39 eyes that comprised the prospective dataset (split into 5 eyes for training and 34 eyes for validating the DL algorithm), and 105 eyes that comprised the retrospective test dataset. Of the total 144 study eyes, 58% had any level of diabetic retinopathy (with and without diabetic macular edema), and the rest were from healthy eyes or eyes of diabetic subjects but without diabetic retinopathy and without macular edema. Grading results in the validation dataset showed that the pseudoaveraged enface scan ranked best in overall scan quality, background noise reduction, and visibility of microaneurysms (p < 0.05). Averaged scan ranked best for motion artifact reduction (p < 0.05). Grading results in the test dataset showed that pseudoaveraging resulted in enhanced small vessels, reduction of background noise, and motion artifact in 100%, 82%, and 98% of scans, respectively. Rates of false-positive/-negative perfusion were zero.
CONCLUSION
Pseudoaveraging is a feasible DL approach to more efficiently improve enface OCTA scan quality without introducing notable image artifacts.
PubMed: 37822004
DOI: 10.1186/s40942-023-00486-5 -
Journal of Clinical Medicine Nov 2023Microvascular disorders represent an uncommon site of tissue hypo-perfusion and damage. Various genetic and acquired causes can be involved. A 65-year-old man was...
BACKGROUND
Microvascular disorders represent an uncommon site of tissue hypo-perfusion and damage. Various genetic and acquired causes can be involved. A 65-year-old man was admitted because of refractory angina, which he had had since the age of 30 years, micro-hematuria, and recurrent transitory ischemic attacks from the age of 64.
METHODS
Hematochemical studies, ECG, Holter monitoring, 2D-echo, cardiac magnetic resonance (CMR), CTA of cerebral vessels, endomyocardial coronary angiography, and kidney biopsy processes were undertaken. Gene mutation analysis was conducted using next-generation sequencing, which included more than 5000 genes associated with inherited diseases.
RESULTS
Hematochemical findings were unremarkable. The ECG, Holter, 2D-echo, and CTA of brain vessels were normal. Cerebral magnetic resonance showed the presence of multiple small foci of ischemia. Coronary and ventricular angiography showed normal arteries with remarkably slow flow and multiple biventricular micro-aneurysms. At the endomyocardial biopsy, five of seven arterioles presented severe lumen obstruction due to hypertrophy and disarray of the muscular coat. Similarly, obstructed pre-glomerular arteries with glomerular sclerosis were seen at the renal biopsy. Genetics identified mutations in the ABCC6, MMP2, and XYLT1 genes, which play pivotal roles in the extracellular matrix.
CONCLUSION
This study described a new genetic microvascular obstructive disease causing progressive hypo-perfusion of the human brain, heart, and kidney.
PubMed: 38002762
DOI: 10.3390/jcm12227150 -
Vascular Medicine (London, England) Apr 2024This study aimed to review the current literature exploring the utility of noninvasive ocular imaging for the diagnosis of peripheral artery disease (PAD). Our search... (Review)
Review
This study aimed to review the current literature exploring the utility of noninvasive ocular imaging for the diagnosis of peripheral artery disease (PAD). Our search was conducted in early April 2022 and included the databases Medline, Scopus, Embase, Cochrane, and others. Five articles were included in the final review. Of the five studies that used ocular imaging in PAD, two studies used retinal color fundus photography, one used optical coherence tomography (OCT), and two used optical coherence tomography angiography (OCTA) to assess the ocular changes in PAD. PAD was associated with both structural and functional changes in the retina. Structural alterations around the optic disc and temporal retinal vascular arcades were seen in color fundus photography of patients with PAD compared to healthy individuals. The presence of retinal hemorrhages, exudates, and microaneurysms in color fundus photography was associated with an increased future risk of PAD, especially the severe form of the disease. The retinal nerve fiber layer (RNFL) was significantly thinner in the nasal quadrant in patients with PAD compared to age-matched healthy individuals in OCT. Similarly, the choroidal thickness in the subfoveal region was significantly thinner in patients with PAD compared to controls. Patients with PAD also had a significant reduction in the retinal and choroidal circulation in OCTA compared to healthy controls. As PAD causes thinning and ischemic changes in retinal vessels, examination of the retinal vessels using retinal imaging techniques can provide useful information about early microvascular damage in PAD. Ocular imaging could potentially serve as a biomarker for PAD. .
Topics: Humans; Optic Disk; Tomography, Optical Coherence; Photography; Peripheral Arterial Disease; Biomarkers; Retinal Vessels
PubMed: 38054219
DOI: 10.1177/1358863X231210866 -
IEEE Journal of Biomedical and Health... Mar 2024Early-stage diabetic retinopathy (DR) presents challenges in clinical diagnosis due to inconspicuous and minute microaneurysms (MAs), resulting in limited research in...
Early-stage diabetic retinopathy (DR) presents challenges in clinical diagnosis due to inconspicuous and minute microaneurysms (MAs), resulting in limited research in this area. Additionally, the potential of emerging foundation models, such as the segment anything model (SAM), in medical scenarios remains rarely explored. In this work, we propose a human-in-the-loop, label-free early DR diagnosis framework called GlanceSeg, based on SAM. GlanceSeg enables real-time segmentation of MA lesions as ophthalmologists review fundus images. Our human-in-the-loop framework integrates the ophthalmologist's gaze maps, allowing for rough localization of minute lesions in fundus images. Subsequently, a saliency map is generated based on the located region of interest, which provides prompt points to assist the foundation model in efficiently segmenting MAs. Finally, a domain knowledge filtering (DKF) module refines the segmentation of minute lesions. We conducted experiments on two newly-built public datasets, i.e., IDRiD and Retinal-Lesions, and validated the feasibility and superiority of GlanceSeg through visualized illustrations and quantitative measures. Additionally, we demonstrated that GlanceSeg improves annotation efficiency for clinicians and further enhances segmentation performance through fine-tuning using annotations. The clinician-friendly GlanceSeg is able to segment small lesions in real-time, showing potential for clinical applications.
PubMed: 38483801
DOI: 10.1109/JBHI.2024.3377592 -
The Egyptian Heart Journal : (EHJ) :... Jun 2024The reported prevalence of patent foramen ovale (PFO) in the general population is variable. It ranges between 8.6 and 42% according to the population studied and the...
BACKGROUND
The reported prevalence of patent foramen ovale (PFO) in the general population is variable. It ranges between 8.6 and 42% according to the population studied and the imaging technique used. We aim to prospectively assess the prevalence and characteristics of PFO and interatrial septum (IAS) abnormalities as well as the related clinical manifestations in a sample of Egyptian population.
RESULTS
This study comprised 1000 patients who were referred for CT coronary angiography (CTCA). Mean age was 52.5 ± 10.9 years. The prevalence of PFO among the studied population was 16.3%; closed PFO (grade I) 44.2%, open PFO (grade II) 50.9%, and open PFO with jet (grade III) 4.9%. Anatomical high-risk PFO features-defined as the presence of at least 2 or more of the following (diameter ≥ 2 mm, length ≥ 10 mm, septal aneurysm "ASA", or redundant septum)-were found in 51.5% of PFOs' population. Other IAS abnormalities as redundant septum (8.6%), ASA (5.3%), Bachmann's bundle (4.5%), microaneurysm (2.6%), and atrial septal defect (ASD) (0.4%) were detected. There was a lower rate of coexistence of ASA with PFO (p = 0.031). Syncope was significantly higher in patients with PFO compared to those without PFO (6.7% vs. 1.6%, p = 0.001). Stroke, transient ischaemic attacks (TIA), and dizziness were similar in both groups. TIA, dizziness, and syncope were significantly higher in patients with IAS abnormalities including PFO compared to those without IAS abnormalities. Syncope was also significantly higher in PFO with high-risk anatomical features compared to those with non-high-risk PFO population (p = 0.02).
CONCLUSION
The prevalence of PFO in our study was approximately 16.3%, almost half of them showed anatomical high-risk features for stroke. Dizziness, syncope and TIA were significantly higher in patients with IAS abnormalities including PFO.
PubMed: 38856789
DOI: 10.1186/s43044-024-00504-3 -
Medicine Nov 2023Although anti-vascular endothelial growth factor (VEGF) treatment is effective for treating diabetic macular edema (DME), the effect of the microaneurysm (MA) status on...
Although anti-vascular endothelial growth factor (VEGF) treatment is effective for treating diabetic macular edema (DME), the effect of the microaneurysm (MA) status on the therapeutic efficacy of an anti-VEGF treatment remains unclear. Our current study investigated the effects of the number and the presence or absence of leaking MAs on DME and the efficacy of anti-VEGF therapy. A total of 51 eyes of 47 DME patients were administered anti-VEGF treatment. Fluorescence angiography results were used to determine the number of MAs and the presence or absence of leakage, with these findings matched to the optical coherence tomography maps. The correlation between the number of MAs and the retinal thicknesses and the influence of the leaking MAs was examined in order to definitively determine the effect of the anti-VEGF treatment. There was a correlation between the number of MAs and the retinal thickness of the sector in both the 6 mm (correlation coefficients: 0.42) and 3 mm (0.34) sectors (P < .001). There was also a correlation between the number of MAs and the retinal thickness in both the 6 mm (0.31) and 3 mm (0.24) sectors after undergoing the treatment (P < .01). There was a significant difference between the mean thickness of the leaking versus the non-leaking MAs in the 6 mm (388 ± 87 μm) and 3 mm (477 ± 108 μm) sectors before treatment (P < .01). There was also a significant difference for the retinal thickness between the sectors with and without leaking MAs after the treatment (P < .01). The degree of retinal edema before treatment is associated with the number of MAs and the presence of leaking MAs. Anti-VEGF treatment is less effective for focal macular edema with large numbers of MAs, which includes leaking MAs.
Topics: Humans; Macular Edema; Diabetic Retinopathy; Cross-Sectional Studies; Retrospective Studies; Angiogenesis Inhibitors; Microaneurysm; Retina; Fluorescein Angiography; Vascular Endothelial Growth Factors; Tomography, Optical Coherence; Intravitreal Injections; Diabetes Mellitus
PubMed: 37932987
DOI: 10.1097/MD.0000000000035888 -
Eye (London, England) Jul 2023This study aims to describe the grading methods and baseline characteristics for UK Biobank (UKBB) participants who underwent retinal imaging in 2009-2010, and to...
BACKGROUND/OBJECTIVES
This study aims to describe the grading methods and baseline characteristics for UK Biobank (UKBB) participants who underwent retinal imaging in 2009-2010, and to characterise individuals with retinal features suggestive of age-related macular degeneration (AMD), glaucoma and retinopathy.
METHODS
Non-mydriatic colour fundus photographs and macular optical coherence tomography (OCT) scans were manually graded by Central Administrative Research Facility certified graders and quality assured by clinicians of the Network of Ophthalmic Reading Centres UK. Captured retinal features included those associated with AMD (≥1 drusen, pigmentary changes, geographic atrophy or exudative AMD; either imaging modality), glaucoma (≥0.7 cup-disc ratio, ≥0.2 cup-disc ratio difference between eyes, other abnormal disc features; photographs only) and retinopathy (characteristic features of diabetic retinopathy with or without microaneurysms; either imaging modality). Suspected cases of these conditions were characterised with reference to diagnostic records, physical and biochemical measurements.
RESULTS
Among 68,514 UKBB participants who underwent retinal imaging, the mean age was 57.3 years (standard deviation 8.2), 45.7% were men and 90.6% were of White ethnicity. A total of 64,367 participants had gradable colour fundus photographs and 68,281 had gradable OCT scans in at least one eye. Retinal features suggestive of AMD and glaucoma were identified in 15,176 and 2184 participants, of whom 125 (0.8%) and 188 (8.6%), respectively, had a recorded diagnosis. Of 264 participants identified to have retinopathy with microaneurysms, 251 (95.1%) had either diabetes or hypertension.
CONCLUSIONS
This dataset represents a valuable addition to what is currently available in UKBB, providing important insights to both ocular and systemic health.
Topics: Male; Humans; Middle Aged; Female; Retinal Drusen; Microaneurysm; Biological Specimen Banks; Macular Degeneration; Tomography, Optical Coherence; Glaucoma; United Kingdom
PubMed: 36329166
DOI: 10.1038/s41433-022-02298-7