Diabetic Retinopathy Disease Research Articles

Effects of insulin resistance and β-cell function on diabetic complications in Korean diabetic patients.

Diabetes mellitus is characterized by insulin resistance (IR) and dysfunctional insulin secretion from pancreatic β-cells. However, little research has been conducted on the relationship between IR and β-cell function in relation to diabetic complications among Korean diabetic patients. This study aimed to examine the differential associations between IR and β-cell function and various diabetic complications among Korean diabetic patients. The analysis employed a common data model (CDM). IR and β-cell function were quantified using the homeostasis model assessment for insulin resistance (HOMA-IR) and β-cell function (HOMA-β), respectively. Hazard ratios for diabetic nephropathy, diabetic retinopathy, and cardiovascular disease (CVD) events were calculated. The study cohort consisted of 2,034 diabetic patients aged over 20 years who visited EUMC between January 2001 and December 2019. Among diabetic patients in the highest quartile of HOMA-IR, the adjusted hazard ratio for total CVD events was 1.76 (95% confidence interval [CI], 1.20-2.57) compared with those in the lowest quartile of HOMA-IR (P = 0.004). In contrast, diabetic patients in the lowest quartile of HOMA-β exhibited an adjusted hazard ratio of 3.91 (95% CI, 1.80-8.49) for diabetic retinopathy compared to those in the highest quartile of HOMA-β (P = 0.001). Insulin resistance and β-cell function exhibited different associations with diabetic complications among Korean diabetic patients. Specifically, lower β-cell function was associated with an increased risk of diabetic retinopathy, whereas higher IR was associated with an increased risk of CVD events. Individuals with pronounced IR should prioritize CVD prevention measures, and those with significant β-cell dysfunction may benefit from early, intensive surveillance for diabetic retinopathy.

Leveraging Optical Coherence Tomography and Angiography Artifacts to Identify Clinicopathological Correlates in Macular Disorders

Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA) are pivotal imaging techniques in diagnosing and managing macular disorders, providing high-resolution cross-sectional images of the retina. Although OCT artifacts are often deemed undesirable, they can paradoxically offer valuable insights into retinal pathology. This review explores the potential of OCT and OCTA artifacts to serve as indicators of pathological correlates in various macular conditions. The study emphasizes the importance of recognizing and leveraging these artifacts to refine clinicopathologic correlates characterizing several macular disorders, including age-related macular degeneration, diabetic retinopathy, and retinal vascular occlusive disease. OCT artifacts can reflect the ultrastructure and composition of pathological features, and their recognition can thus expand the understanding of the pathogenesis and improve the diagnostic interpretation of macular disorders. With the widespread use of OCT and OCTA technologies, identifying artifacts with clinicopathologic significance is of paramount importance and may have significant implications for management and prognosis.

Grading of diabetic retinopathy using a pre-segmenting deep learning classification model: Validation of an automated algorithm.

To validate the performance of autonomous diabetic retinopathy (DR) grading by comparing a human grader and a self-developed deep-learning (DL) algorithm with gold-standard evaluation. We included 500, 6-field retinal images graded by an expert ophthalmologist (gold standard) according to the International Clinical Diabetic Retinopathy Disease Severity Scale as represented with DR levels 0-4 (97, 100, 100, 103, 100, respectively). Weighted kappa was calculated to measure the DR classification agreement for (1) a certified human grader without, and (2) with assistance from a DL algorithm and (3) the DL operating autonomously. Using any DR (level 0 vs. 1-4) as a cutoff, we calculated sensitivity, specificity, as well as positive and negative predictive values (PPV and NPV). Finally, we assessed lesion discrepancies between Model 3 and the gold standard. As compared to the gold standard, weighted kappa for Models 1-3 was 0.88, 0.89 and 0.72, sensitivities were 95%, 94% and 78% and specificities were 82%, 84% and 81%. Extrapolating to a real-world DR prevalence of 23.8%, the PPV were 63%, 64% and 57% and the NPV were 98%, 98% and 92%. Discrepancies between the gold standard and Model 3 were mainly incorrect detection of artefacts (n = 49), missed microaneurysms (n = 26) and inconsistencies between the segmentation and classification (n = 51). While the autonomous DL algorithm for DR classification only performed on par with a human grader for some measures in a high-risk population, extrapolations to a real-world population demonstrated an excellent 92% NPV, which could make it clinically feasible to use autonomously to identify non-DR patients.

Photobiomodulation in Ophthalmology: A Comprehensive Review of Bench-to-Bedside Research and Clinical Integration.

Photobiomodulation (PBM), also known as low-level laser therapy, is an emerging therapeutic modality in ophthalmology, attracting increasing interest for its potential to manage a variety of ocular conditions. PBM employs low-energy light within the red and near-infrared spectrum to penetrate biological tissues, where it interacts with cellular chromophores. This interaction is believed to enhance mitochondrial function, boost adenosine triphosphate (ATP) production, and reduce oxidative stress, leading to improved cellular repair and tissue regeneration. Recent bench research has demonstrated PBM's efficacy in cellular and animal models, showing its ability to modulate inflammatory processes and promote healing in retinal and corneal diseases. For instance, in retinal models, PBM has been observed to reduce apoptosis and support cell survival under stress conditions. Similarly, studies in corneal models suggest that PBM can accelerate wound healing and reduce scarring. Clinical trials further corroborate these findings, revealing that PBM can enhance treatment outcomes in several ocular diseases, including age-related macular degeneration, diabetic retinopathy, and dry eye disease. Patients undergoing PBM have reported improvements in visual acuity, reduced retinal inflammation, and better tear film stability, highlighting its potential as an adjunctive therapy. This review also explores the integration of PBM into clinical practice, discussing current treatment protocols, safety considerations, and the latest advancements in PBM technology. By offering a holistic overview, the review aims to provide clinicians and researchers with valuable insights into PBM's role in modern ophthalmic care, emphasizing its potential to enhance treatment strategies and improve patient outcomes.

The effects of micro- and macrovascular diabetic complications on ischemic stroke in patients with type 2 diabetes mellitus

Objectives: The present study aimed to examine the effects of diabetes complications on the ischemic stroke risk among patients with type 2 diabetes mellitus (T2DM). Patients and methods: The medical records of all patients (n=5,468) who were admitted to a tertiary care hospital between January 1, 2021, and June 1, 2022, were retrospectively reviewed. Of 911 patients diagnosed with T2DM for at least two years, 37 patients with a history of hemorrhagic cerebrovascular disease were excluded. Consequently, the study was conducted with 874 patients (460 males, 414 females; mean age: 65.5±12.1 years; range, 39 to 92 years) with T2DM. Demographic data, presence of chronic disease other than diabetes, duration of diabetes, retinopathy, nephropathy, peripheral arterial disease, and diabetes medications were recorded. The patients were divided into two groups: those with and without a history of ischemic stroke. The two groups were compared in terms of demographic characteristics and diabetes complications. Results: The prevalence of ischemic stroke was 18.6% (n=163). Patients with ischemic stroke were older than those without ischemic stroke, had longer diabetes durations, and had higher rates of hypertension, hyperlipidemia, and insulin use (p=0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively). Diabetic retinopathy (41.7%), diabetic nephropathy (27.6%), and peripheral arterial disease (16.6%) were more commonly observed among patients with ischemic stroke compared to the others. Examining the parameters differing between the groups, diabetes duration, hypertension, insulin use, and peripheral arterial disease were found to be independent risk factors for ischemic stroke (p<0.001, p<0.001, p=0.001, and p=0.001, respectively). Conclusion: Examining the relationship between diabetes complications and ischemic stroke risk from a broader perspective, the present study provided important implications for clinical management. Large-scale studies are needed in the future.

Intertemporal Decision-Making, Diabetes Self-Management, and Health Outcomes in Patients With Type 2 Diabetes.

The purpose of this study was to identify the independent factors associated with intertemporal decision-making and to examine its relationship with diabetes self-management behaviors, glucose variability, and diabetes complications in patients with diabetes. A cross-sectional study using convenience sampling (n = 368) was conducted in patients with type 2 diabetes (T2DM) between November 2021 and April 2023. Data were collected using self-reported questionnaires and retrieval of clinical information from medical records. Intertemporal decision-making was operationalized using delay discounting. The outcome variables included diabetes self-management behaviors, A1C, diabetic retinopathy, and carotid artery disease. Hierarchical regression and binary logistic regression models were used to explore the relationships among intertemporal decision-making, self-management, A1C, and carotid artery disease. The analyses showed that intertemporal decision-making was negatively associated with physical activity and carotid artery disease, in which individuals with lower delay discounting tended to have healthier physical activity; when the delay discounting rate increased 1 unit, the risk of the carotid artery disease increased by 39.8%. The study reveals that a lower delay discounting can promote healthier physical activity and decrease the incidence of carotid artery disease. These results offer new knowledge for researchers and clinicians to consider intertemporal decision-making in developing interventional programs to improve physical activity and reduce carotid artery complication in patients with T2DM when providing care.

Polyunsaturated fatty acids and diabetic microvascular complications: a Mendelian randomization study.

Observational studies and clinical trials have implicated polyunsaturated fatty acids (PUFAs) in potentially safeguarding against diabetic microvascular complication. Nonetheless, the causal nature of these relationships remains ambiguous due to conflicting findings across studies. This research employs Mendelian randomization (MR) to assess the causal impact of PUFAs on diabetic microvascular complications. We identified instrumental variables for PUFAs, specifically omega-3 and omega-6 fatty acids, using the UK Biobank data. Outcome data regarding diabetic microvascular complications were sourced from the FinnGen Study. Our analysis covered microvascular outcomes in both type 1 and type 2 diabetes, namely diabetic neuropathy (DN), diabetic retinopathy (DR), and diabetic kidney disease (DKD). An inverse MR analysis was conducted to examine the effect of diabetic microvascular complications on PUFAs. Sensitivity analyses were performed to validate the robustness of the results. Finally, a multivariable MR (MVMR) analysis was conducted to determine whether PUFAs have a direct influence on diabetic microvascular complications. The study indicates that elevated levels of genetically predicted omega-6 fatty acids substantially reduce the risk of DN in type 2 diabetes (odds ratio (OR): 0.62, 95% confidence interval (CI): 0.47-0.82, p = 0.001). A protective effect against DR in type 2 diabetes is also suggested (OR: 0.75, 95% CI: 0.62-0.92, p = 0.005). MVMR analysis confirmed the stability of these results after adjusting for potential confounding factors. No significant effects of omega-6 fatty acids were observed on DKD in type 2 diabetes or on any complications in type 1 diabetes. By contrast, omega-3 fatty acids showed no significant causal links with any of the diabetic microvascular complications assessed. Our MR analysis reveals a causal link between omega-6 fatty acids and certain diabetic microvascular complications in type 2 diabetes, potentially providing novel insights for further mechanistic and clinical investigations into diabetic microvascular complications.

OctoVision: A Smart System for Diabetic Retinopathy Disease Detection

Diabetic retinopathy (DR) is the major cause of vision impairment and blindness in diabetics. Early detection and treatments are critical in preventing irreparable retinal damage. Manual detection of diabetic retinopathy by an ophthalmologist takes a long time, and patients must suffer greatly during this time. This paper presents an automated approach for rapid DR detection using the DenseNet-121 architecture. Our model achieves an accuracy exceeding 80%, with a precision score of 81% and a recall score of 86%, indicating its high effectiveness in detecting DR. Additionally, we developed a server-based implementation where the trained model is deployed. Images captured by a camera are uploaded to a cloud server, which processes them and sends back a diagnostic response. This study contributes to continuing efforts to create efficient and reliable techniques for early DR identification, resulting in earliermanagement and better patient outcomes.

Plasma matrix metalloproteinases and tissue inhibitors of metalloproteinases explored in relation to the severity and progression of diabetic retinopathy in patients with type 1 diabetes: baseline and prospective analyses

AimsTo explore whether circulating matrix metalloproteinase-2 (MMP-2), MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin, MMP-9/tissue inhibitor of metalloproteinase-1 (TIMP-1), MMP-14, TIMP-2 and TIMP-3 were associated with the severity and progression of diabetic retinopathy...

Diabetic myonecrosis complicated by emphysematous pyomyositis and abscess caused by Escherichia coli: a case report

BackgroundNecrotizing myopathies and muscle necrosis can be caused by immune-mediated mechanisms, drugs, ischemia, and infections, and differential diagnosis may be challenging.Case presentationWe describe a case of diabetic myonecrosis complicated by pyomyositis and abscess caused by Escherichia coli. A white woman in her late forties was admitted to the hospital with a 1.5 week history of bilateral swelling, weakness, and mild pain of the lower extremities and inability to walk. She had a history of type 1 diabetes complicated by diabetic retinopathy, neuropathy, nephropathy, and end-stage renal disease. C-reactive protein was 203 mg/l, while creatinine kinase was only mildly elevated to 700 IU/l. Magnetic resonance imaging of her lower limb muscles showed extensive edema, and muscle biopsy was suggestive of necrotizing myopathy with mild inflammation. No myositis-associated or myositis-specific antibodies were detected. Initially, she was suspected to have seronegative immune-mediated necrotizing myopathy, but later her condition was considered to be explained better by diabetic myonecrosis with multifocal involvement. Her symptoms alleviated without any immunosuppressive treatment. After a month, she developed new-onset and more severe symptoms in her right posterior thigh. She was diagnosed with emphysematous urinary tract infection and emphysematous myositis and abscess of the right hamstring muscle. Bacterial cultures of drained pus from abscess and urine were positive for Escherichia coli. In addition to abscess drainage, she received two 3–4-week courses of intravenous antibiotics. In the discussion, we compare the symptoms and findings typically found in pyomyositis, immune-mediated necrotizing myopathy, and diabetic myonecrosis (spontaneous ischemic necrosis of skeletal muscle among people with diabetes). All of these diseases may cause muscle weakness and pain, muscle edema in imaging, and muscle necrosis. However, many differences exist in their clinical presentation, imaging, histology, and extramuscular symptoms, which can be useful in determining diagnosis. As pyomyositis often occurs in muscles with pre-existing pathologies, the ischemic muscle has likely served as a favorable breeding ground for the E. coli in our case.ConclusionsIdentifying the etiology of necrotizing myopathy is a diagnostic challenge and often requires a multidisciplinary assessment of internists, pathologists, and radiologists. Moreover, the presence of two rare conditions concomitantly is possible in cases with atypical features.

مدى إنتشار عوامل الخطر وارتباطها في تطور إعتلال الشبكية السكري في قسم طب العيون، مركز طبرق الطبي، ليبيا

Diabetic retinopathy is a condition of the eyes that can affect people with diabetes. This is the degree at which the retina's blood vessels are damaged by high blood sugar. These vascular structures can expand and rupture. Additionally, the vessels might close, preventing the circulation of blood. Sometimes, abnormally new blood vessels might grow on the retina. Any of the foregoing changes could impair your vision. The aim of this study is to identify risk factors that may enhance the development of diabetic retinopathy and explore strategies for reducing the possibility of visual impairment caused by this condition. A prospective cross-sectional study of diabetic patients registered at the Eye Department of Tobruk Medical Center in Tobruk, Libya between (01.06.2023 to 29.02.2024). Data was collected using a self-administered questionnaire. Grading of DR (diabetic retinopathy) was done by slit-lamp examination and fundoscopy by an ophthalmologist. Descriptive analysis included percentage, mean of age, and p-value by using SPSS 25. Result: There were 85 diabetic patients, with a mean age of 63.5 and an age range of 31 to 85 years. Of these, 98.8% were of Libyan nationality and 96.4% were place of residencein Tobruk. Forty-three women were present. Compared to individuals with diabetes for less than ten years, those with diabetes for eleven to fifteen years had an almost five-fold increased chance of having diabetic retinopathy disease (DR). Patients with poor diabetes control (HbA1c > 9) had a 25-fold increased chance of developing PR compared to those with adequate control (HbA1c < 7.5). Conclusion: Patients with uncontrolled diabetes and those with the disease for a longer period of time are more likely to develop diabetic retinopathy and experience visual impairment. Key word: Diabetic retinopathy, poor diabetes control, longer period of diabetes, Tobruk, Libya.

The role of probiotics on microvascular complications of type-2 diabetes: Nephropathy and retinopathy.

Diabetes is a multifactorial disorder that involves several molecular mechanisms and is still one of the key global health challenges with increasing prevalence and incidence. Gut microbiome dysbiosis could activate and recognize receptors that trigger the inflammation response and modulation of insulin sensitivity. In addition, the intricate role of gut microbiota dysbiosis in the onset and development of T2D (Type 2 diabetes mellitus) and associated microvascular complications was identified. These complications include diabetic nephropathy (DN) and diabetic retinopathy (DR), diabetic neuropathy, cerebrovascular disorders, and coronary heart disease. A recent interesting strategy to improve these complications is probiotics administration. The safety and health effects of probiotics against various diseases have been validated by various in vitro, in vivo and clinical studies. In this review, the related mechanisms between the gut microbiome, initiation, and progression of T2D and its common microvascular complications (DN and DR) have been discussed.

Retinal vascular morphological characteristics in diabetic retinopathy: an artificial intelligence study using a transfer learning system to analyze ultra-wide field images.

To investigate the morphological characteristics of retinal vessels in patients with different severity of diabetic retinopathy (DR) and in patients with or without diabetic macular edema (DME). The 239 eyes of DR patients and 100 eyes of healthy individuals were recruited for the study. The severity of DR patients was graded as mild, moderate and severe non-proliferative diabetic retinopathy (NPDR) according to the international clinical diabetic retinopathy (ICDR) disease severity scale classification, and retinal vascular morphology was quantitatively analyzed in ultra-wide field images using RU-net and transfer learning methods. The presence of DME was determined by optical coherence tomography (OCT), and differences in vascular morphological characteristics were compared between patients with and without DME. Retinal vessel segmentation using RU-net and transfer learning system had an accuracy of 99% and a Dice metric of 0.76. Compared with the healthy group, the DR group had smaller vessel angles (33.68±3.01 vs 37.78±1.60), smaller fractal dimension (Df) values (1.33±0.05 vs 1.41±0.03), less vessel density (1.12±0.44 vs 2.09±0.36) and fewer vascular branches (206.1±88.8 vs 396.5±91.3), all P<0.001. As the severity of DR increased, Df values decreased, P=0.031. No significant difference between the DME and non-DME groups were observed in vascular morphological characteristics. In this study, an artificial intelligence retinal vessel segmentation system is used with 99% accuracy, thus providing with relatively satisfactory performance in the evaluation of quantitative vascular morphology. DR patients have a tendency of vascular occlusion and dropout. The presence of DME does not compromise the integral retinal vascular pattern.

Expert opinion regarding early screening, patient awareness, and telemedicine practices in Indian settings

Objective: To collect clinicians’ perspectives regarding the significance of early screening, patient awareness, and telemedicine practice in routine Indian settings for diabetes management. Methodology: The study employed a 25-item questionnaire to gather insights from specialists across different Indian settings regarding their perspectives on early screening, patient awareness, and telemedicine practices among diabetologists. Results: According to the cross-sectional survey, 59% of respondents believed that regular awareness programs were helpful in the early screening of diabetes among high-risk individuals. Meanwhile, 64% of clinicians reported that clinical-level screening was a more effective tool for early screening. Around 74% of clinicians reported that microvascular complications namely diabetic retinopathy, diabetic neuropathy, and diabetic kidney diseases should be targeted during early screening of diabetes. The American Diabetes Association (ADA) risk score was the most commonly used risk score for early diabetes screening, according to 54% of clinicians. Moreover, 67% of clinicians reported that 11 to 25% of diabetic individuals had complications of lipitension, and 64% reported that 11 to 20% of T2DM individuals had depression. Regarding telemedicine, 65% of clinicians preferred to use it occasionally. However, at an individual level, factors like cost, literacy, less familiarity with using the tool, and emotional reasons hindered the effective adoption of telemedicine, as reported by 56% of clinicians. Conclusion: The survey highlighted the effectiveness of awareness programs and clinical-level screening for early diabetes management, emphasizing the importance of targeting microvascular complications. Increased prevalence of complications like lipitension and depression was noted in diabetic individuals. Telemedicine, though recognized as valuable, faces challenges due to individual-level factors.

Mutant kri1l causes abnormal retinal development via cell cycle arrest and apoptosis induction

Damage to the ribosome or an imbalance in protein biosynthesis can lead to some human diseases, such as diabetic retinopathy (DR) and other eye diseases. Here, we reported that the kri1l gene was responsible for retinal development. The kri1l gene encodes an essential component of the rRNA small subunit processome. The retinal structure was disrupted in kri1l mutants, which resulted in small eyes. The boundaries of each layer of cells in the retina were blurred, and each layer of cells was narrowed and decreased. The photoreceptor cells and Müller glia cells almost disappeared in kri1l mutants. The lack of photoreceptor cells caused a fear of light response. The development of the retina started without abnormalities, and the abnormalities began two days after fertilization. In the kri1l mutant, retinal cell differentiation was defective, resulting in the disappearance of cone cells and Müller cells. The proliferation of retinal cells was increased, while apoptosis was also enhanced in kri1l mutants. γ-H2AX upregulation indicated the accumulation of DNA damage, which resulted in cell cycle arrest and apoptosis. The kri1l mutation reduced the expression of some opsin genes and key retinal genes, which are also essential for retinal development.

Classification of Diabetic Retinopathy Disease Levels by Extracting Spectral Features Using Wavelet CNN.

Diabetic retinopathy (DR) arises from blood vessel damage and is a leading cause of blindness on a global scale. Clinical professionals rely on examining fundus images to diagnose the disease, but this process is frequently prone to errors and is tedious. The usage of computer-assisted techniques offers assistance to clinicians in detecting the severity levels of the disease. Experiments involving automated diagnosis employing convolutional neural networks (CNNs) have produced impressive outcomes in medical imaging. At the same time, retinal image grading for detecting DR severity levels has predominantly focused on spatial features. More spectral features must be explored for a more efficient performance of this task. Analysing spectral features plays a vital role in various tasks, including identifying specific objects or materials, anomaly detection, and differentiation between different classes or categories within an image. In this context, a model incorporating Wavelet CNN and Support Vector Machine has been introduced and assessed to classify clinically significant grades of DR from retinal fundus images. The experiments were conducted on the EyePACS dataset and the performance of the proposed model was evaluated on the following metrics: precision, recall, F1-score, accuracy, and AUC score. The results obtained demonstrate better performance compared to other state-of-the-art techniques.

Sulforaphane and ophthalmic diseases.

Sulforaphane (SFN) is an organosulfur compound categorized as an isothiocyanate (ITC), primarily extracted from cruciferous vegetables like broccoli and cabbage. The molecular formula of sulforaphane (SFN) is C6H11NOS2. SFN is generated by the hydrolysis of glucoraphanin (GRP) through the enzyme myrosinase, showing notable properties including anti-diabetic, anti-inflammatory, antimicrobial, anti-angiogenic, and anticancer attributes. Ongoing clinical trials are investigating its potential in diseases such as cancer, neurodegenerative diseases, diabetes-related complications, chronic kidney disease, cardiovascular disease, and liver diseases. Several animal carcinogenesis models and cell culture models have shown it to be a very effective chemopreventive agent, and the protective effects of SFN in ophthalmic diseases have been linked to multiple mechanisms. In murine models of diabetic retinopathy and age-related macular degeneration, SFN delays retinal photoreceptor cell degeneration through the Nrf2 antioxidative pathway, NF-κB pathway, AMPK pathway, and Txnip/mTOR pathway. In rabbit models of keratoconus and cataract, SFN has been shown to protect corneal and lens epithelial cells from oxidative stress injury by activating the Keap1-Nrf2-ARE pathway and the Nrf-2/HO-1 antioxidant pathway. Oral delivery or intraperitoneal injection at varying concentrations are the primary strategies for SFN intake in current preclinical studies. Challenges remain in the application of SFN in eye disorders due to its weak solubility in water and limited bioavailability because of the presence of blood-ocular barrier systems. This review comprehensively outlines recent research on SFN, elucidates its mechanisms of action, and discusses potential therapeutic benefits for eye disorders such as age-related macular degeneration (AMD), diabetic retinopathy (DR), cataracts, and other ophthalmic diseases, while also indicating directions for future clinical research to achieve efficient SFN treatment for ophthalmic diseases.

Evaluation of nail fold capillaroscopy changes in patients with diabetic retinopathy and healthy controls, and its correlation with disease duration, HbA1c levels and severity of diabetic retinopathy: An observational study.

Background Diabetic retinopathy (DR) is an important microvascular complication of long-term type 2 diabetes mellitus (T2DM) leading to blindness if not properly diagnosed and managed. It can develop as early as 7 years before the diagnosis of diabetes. Nail fold capillaroscopy (NFC) is a non-invasive technique for observing capillary microvasculature and there are few studies which have explored the use of NFC in diabetes mellitus patients. Objective To study the nail fold capillaroscopic alterations in patients with T2DM having diabetic retinopathy and compare them to healthy controls. The secondary objective was to correlate the NFC findings with the duration of diabetes, haemoglobin A1c (HbA1c) levels and the severity of DR. Materials and methods This cross-sectional observational study enrolled 200 patients - 100 cases with T2DM having diabetic retinopathy (as per the American Diabetes Association criteria and Diabetic Retinopathy Disease Severity Scale) and 100 healthy age and sex-matched controls. All patients were subjected to NFC and ophthalmological assessment. Results NFC revealed that patients with DR showed significantly higher frequencies of tortuous, dilated, bushy, meandering, angulated capillaries, avascular areas and micro-haemorrhages as compared to healthy controls (p < 0.05). In proliferative DR (PDR), the frequency of tortuous, bushy capillaries, and avascular areas was statistically high and the capillary density was reduced as compared to non-proliferative DR. The DR patients with longer disease duration (>20) years had a significantly higher frequency of tortuous capillaries, avascular areas, meandering, angulated and dilated capillaries. The frequency of tortuosity, avascular areas, and bushy areas was significantly higher in patients with poor glycaemic control (HbA1c >11). Limitations A larger sample size study with different demographic populations could have provided a broader picture of NFC changes in T2DM patients with DR. Discussion NFC may act as a surrogate marker of retinal involvement in patients with DM and should be performed at regular intervals. Conclusion NFC is a quick, simple, safe, and non-invasive method to assess the capillaroscopic alterations in diabetic patients which inturn can help in assessing the severity of DR.

Enhancing deep learning pre-trained networks on diabetic retinopathy fundus photographs with SLIC-G.

Diabetic retinopathy disease contains lesions (e.g., exudates, hemorrhages, and microaneurysms) that are minute to the naked eye. Determining the lesions at pixel level poses a challenge as each pixel does not reflect any semantic entities. Furthermore, the computational cost of inspecting each pixel is expensive because the number of pixels is high even at low resolution. In this work, we propose a hybrid image processing method. Simple Linear Iterative Clustering with Gaussian Filter(SLIC-G) for the purpose of overcoming pixel constraints. The SLIC-G image processing method is divided into two stages: (1) simple linear iterative clustering superpixel segmentation and (2) Gaussian smoothing operation. In such a way, a large number of new transformed datasets are generated and then used for model training. Finally, two performance evaluation metrics that are suitable for imbalanced diabetic retinopathy datasets were used to validate the effectiveness of the proposed SLIC-G. The results indicate that, in comparison to prior published works' results, the proposed SLIC-G shows better performance on image classification of class imbalanced diabetic retinopathy datasets. This research reveals the importance of image processing and how it influences the performance of deep learning networks. The proposed SLIC-G enhances pre-trained network performance by eliminating the local redundancy of an image, which preserves local structures, but avoids over-segmented, noisy clips. It closes the research gap by introducing the use of superpixel segmentation and Gaussian smoothing operation as image processing methods in diabetic retinopathy-related tasks.

Association between obstructive coronary disease and diabetic retinopathy: Cross-sectional study of coronary angiotomography and multimodal retinal imaging

AimsTo investigate the association between diabetic retinopathy (DR) and coronary artery disease (CAD) using coronary angiotomography (CCTA) and multimodal retinal imaging (MMRI) with ultra-widefield retinography and optical coherence tomography angiography and structural domain. MethodsSingle-center, cross-sectional, single-blind. Patients with diabetes who had undergone CCTA underwent MMRI. Uni and multivariate analysis were used to assess the association between CAD and DR and to identify variables independently associated with DR. ResultsWe included 171 patients, 87 CAD and 84 non-CAD. Most CAD patients were males (74 % vs 38 %, P < 0.01), insulin users (52 % vs 38 %, p < 0.01) and revascularized (64 %). They had a higher prevalence of DR (48 % vs 22 %, p = 0.01), microaneurysms (25 % vs 13 %, p = 0.04), intraretinal cysts (22 % vs 8 %, p = 0.01) and areas of reduced capillary density (46 % vs 20 %, p < 0.01). CAD patients also had lower mean vascular density (MVD) (15.7 % vs 16.5,%, p = 0.049) and foveal avascular zone (FAZ) circularity (0.64 ± 0.1 vs 0.69 ± 0.1, p = 0.04). There were significant and negative correlations between Duke coronary score and MVD (r = −0.189; p = 0.03) and FAZ circularity (r = −0,206; p = 0.02). CAD, DM duration and insulin use independently associated with DR. ConclusionsCAD patients had higher prevalence of DR and lower MVD. CAD, DM duration and insulin use were independently associated with DR.