Pyroptosis of Vascular Smooth Muscle Cells as a Potential New Target for Preventing Vascular Diseases.

Vascular remodeling is the adaptive response of the vessel wall to physiological and pathophysiological changes, closely linked to vascular diseases. Vascular smooth muscle cells (VSMCs) play a crucial role in this process. Pyroptosis, a form of programmed cell death characterized by excessive release of inflammatory factors, can cause phenotypic transformation of VSMCs, leading to their proliferation, migration, and calcification-all of which accelerate vascular remodeling. Inhibition of VSMC pyroptosis can delay this process. This review summarizes the impact of pyroptosis on VSMCs and the pathogenic role of VSMC pyroptosis in vascular remodeling. We also discuss inhibitors of key proteins in pyroptosis pathways and their effects on VSMC pyroptosis. These findings enhance our understanding of the pathogenesis of vascular remodeling and provide a foundation for the development of novel medications that target the control of VSMC pyroptosis as a potential treatment strategy for vascular diseases.

Cardiovascular mortality in bipolar disorder: Population-based cohort study.

BACKGROUND: Limited evidence base on cause-specific excess cardiovascular disease (CVD) mortality in bipolar disorder (BD) is a barrier to developing preventive interventions aimed at reducing the persistent mortality gap in BD. OBJECTIVE: To investigate cause-specific CVD mortality in BD. METHODS: We identified all individuals aged 15+ years during 2004-2018 with a diagnosis of BD using Finnish nationwide routine data. Standardised mortality ratios (SMR) with 95% confidence intervals (CI) were calculated using the mortality rates in the general population as weights. RESULTS: 53,273 individuals with BD (57% women; median age at BD diagnosis, 40 years), were followed up for 428,426 person-years (median, 8.2 years). There were 5988 deaths due to any cause, of which 26% were due to CVD. The leading cause of absolute excess CVD mortality was coronary artery disease (CAD). The leading causes of relative excess mortality were cardiomegaly (SMR, 4.51; 95% CI, 3.58-5.43), venous thromboembolism (3.03; 2.26-3.81), cardiomyopathy (2.46; 1.95-2.97), and hypertensive heart disease (2.12; 1.71-2.54). The leading causes of absolute CVD mortality showed markedly lower relative excess, including CAD (1.47; 1.34-1.61), ischaemic stroke (1.31; 1.06-1.54), and acute myocardial infarction (1.12; 0.98-1.25). Due to the higher relative excess mortality, structural and functional heart disorders contributed as much as atherosclerotic and ischaemic disorders to the absolute excess mortality. CONCLUSIONS: Cardiomyopathy and hypertensive heart disease as the leading causes of relative excess mortality emphasise the contribution of structural and functional heart disorders to the overall excess mortality alongside coronary artery disease. Interventions targeted at these modifiable causes of death should be priorities in the prevention of premature excess CVD mortality in BD.

Tortuosity in non-atherosclerotic vascular diseases is associated with age, arterial aneurysms, and hypertension.

BACKGROUND: Increased arterial tortuosity has been associated with various cardiovascular complications. However, the extent and role of arterial tortuosity in non-atherosclerotic vascular diseases remain to be fully elucidated. This study aimed to assess arterial tortuosity index (ATI) in patients with non-atherosclerotic vascular diseases and the associated factors. METHODS: This is a retrospective analysis of patients with non-atherosclerotic vascular diseases referred to the Malformation and Rare Vascular Disease Center at the University Hospital in Lausanne (Switzerland). Computed tomography angiography (CTA) images performed between October 2010 and April 2022 were retrieved and the aortic tortuosity index (ATI) was calculated. Patients were classified based on diagnosis into the following groups: arterial dissection & aneurysm, arteritis & autoimmune disease, hereditary connective tissue diseases, and fibromuscular dysplasia (FMD). Univariate and multivariate logistic regression analysis was used to determine potentially relevant predictors of aortic tortuosity. RESULTS: The mean age upon computed tomography angiography (CTA) was 46.8 (standard deviation [SD] 14.6) years and 59.1% of the patients were female. Mean ATI was higher in patients over 60 years old (1.27), in those with arterial aneurysms (mean: 1.11), and in those diagnosed with hypertension (mean: 1.13). When only patients over 60 years old were considered, those diagnosed with connective tissue diseases had the highest ATI. At multivariate regression analysis, increasing age (p < 0.05), presence of arterial aneurysms (p < 0.05), and hypertension (p < 0.05) were independently associated with ATI. CONCLUSIONS: The ATI may be a promising tool in diagnostic evaluation, cardiovascular risk stratification, medical or surgical management, and prognostic assessment in several non-atherosclerotic vascular conditions. Further studies with longitudinal design and larger cohorts are needed to validate the role of ATI in the full spectrum of vascular diseases.

2023 Update on Vascular Anesthesia.

The authors thank thank the editors for this opportunity to review the recent literature on vascular surgery and anesthesia and provide this clinical update. The last in a series of updates on this topic was published in 2019.1 This review explores evolving discussions and current trends related to vascular surgery and anesthesia that have been published since then. The focus is on the major points discussed in the recent literature in the following areas: carotid artery surgery, infrarenal aortic surgery, peripheral vascular surgery, and the preoperative evaluation of vascular surgical patients.

Angiotensin II: Role in oxidative stress, endothelial dysfunction, and diseases.

Angiotensin II (Ang II) is a protein hormone capable of physiologically regulating blood pressure through diverse mechanisms. Ang II is mainly produced by the liver at homeostatic levels. However, excessive production of Ang II is closely associated with a series of pathological events in the body. The endothelial dysfunction is one of these pathological events that can drive vascular anomalies. The excessive exposure of endothelial cells (ECs) to Ang II may induce endothelial dysfunction via diverse mechanisms. One of these mechanisms is Ang II-mediated mitochondrial oxidative stress. In this mini-review, we aimed to discuss the molecular mechanisms of Ang II-mediated endothelial dysfunction through mitochondrial oxidative stress and the protective role of nitric oxide in ECs. Deciphering these mechanisms may disclose novel therapeutic strategies to prevent endothelial dysfunction and associated diseases induced by elevated leves of Ang II in the blood.

The association between circulating CD34+CD133+ endothelial progenitor cells and reduced risk of Alzheimer's disease in the Framingham Heart Study.

Aim: Endothelial dysfunction has been associated with both cerebrovascular pathology and Alzheimer's disease (AD). However, the connection between circulating endothelial cells and the risk of AD remains uncertain. The objective was to leverage data from the Framingham Heart Study to investigate various circulating endothelial subtypes and their potential correlations with the risk of AD. Methods: The study conducted data analyses using Cox proportional hazard regression and linear regression methods. Additionally, genome-wide association study (GWAS) was carried out to further explore the data. Results: Among the eleven distinct circulating endothelial subtypes, only circulating endothelial progenitor cells (EPCs) expressing CD34+CD133+ were found to be negatively and dose-dependently associated with reduced AD risk. This association persisted even after adjusting for age, sex, years of education, apolipoprotein E (APOE) ε4 status, and various vascular diseases. Particularly noteworthy was the significant association observed in individuals with hypertension and cerebral microbleeds. Consistently, positive associations were identified between CD34+CD133+ EPCs and specific brain regions, such as higher proportions of circulating CD34+CD133+ cells correlating with increased volumes of white matter and the hippocampus. Additionally, a GWAS study unveiled that CD34+CD133+ cells influenced AD risk specifically in individuals with homozygous genotypes for variants in two stem cell-related genes: kirre like nephrin family adhesion molecule 3 (KIRREL3, rs580382 CC and rs4144611 TT) and exocyst complex component 6B (EXOC6B, rs61619102 CC). Conclusions: The findings suggest that circulating CD34+CD133+ EPCs possess a protective effect and may offer a new therapeutic avenue for AD, especially in individuals with vascular pathology and those carrying specific genotypes of KIRREL3 and EXOC6B genes.

A comprehensive meta-analysis on the association of SGLT2is and GLP-1RAs with vascular diseases, digestive diseases and fractures.

AIM: Sodium-glucose cotransporter-2 inhibitors (SGLT2is) and glucagon-like peptide 1 receptor agonists (GLP-1RAs) are two new classes of antidiabetic agents. We aimed to evaluate the association between these two drug classes and risk of various vascular diseases, digestive diseases and fractures. METHODS: Large randomized trials of SGLT2is and GLP-1RAs were included. Outcomes of interest were the various serious adverse events related to vascular diseases, digestive diseases and fractures. We performed meta-analyses using synthesize risk ratio (RR) and 95% confidence interval (CI) as effect size. RESULTS: We included 27 large trials. SGLT2is had significant association with less hypertension (RR 0.70, 95% CI 0.54-0.91), hypertensive crisis (RR 0.63, 95% CI 0.47-0.84), varicose vein (RR 0.34, 95% CI 0.13-0.92), and vomiting (RR 0.55, 95% CI 0.31-0.97); but more spinal compression fracture (RR 1.73, 95% CI 1.02-2.92) and tibia fracture. GLP-1RAs had significant association with more deep vein thrombosis (RR 1.92, 95% CI 1.23-3.00), pancreatitis (RR 1.54, 95% CI 1.07-2.22), and cholecystitis acute (RR 1.51, 95% CI 1.08-2.09); but less rib fracture (RR 0.59, 95% CI 0.35-0.97). Sensitivity analyses suggested that our findings were robust. CONCLUSIONS: SGLT2is may have protective effects against specific vascular and digestive diseases, whereas they may increase the incidence of site-specific fractures (e.g., spinal compression fracture). GLP-1RAs may have protective effects against site-specific fractures (i.e., rib fracture), whereas they may increase the incidence of specific vascular and digestive diseases. These findings may help to make a choice between SGLT2is and GLP-1RAs in clinical practice.

Multiwavelength laser diode based portable photoacoustic and ultrasound imaging system for point of care applications.

Vascular diseases are a leading cause of death and disability worldwide. Despite having precursor conditions like peripheral arterial disease (PAD), they are often only diagnosed after the onset of stroke or heart attack. Low-cost, portable, noninvasive, point-of-care (POC), label-free assessment of deep vascular function benefits PAD diagnosis, especially in resource poor settings of the world. Doppler ultrasound-based blood flow measurements can diagnose PAD, albeit with limited sensitivity and specificity. To overcome this, here, we propose the first-of-its-kind dual-modality photoacoustic-and-ultrasound (PAUS) imaging system that integrates a multiwavelength pulsed laser diode (PLD) with a compact ultrasound data acquisition unit. The mesoscopic imaging depth of the portable PLD-PAUS system was validated using tissue phantoms, and its multispectral photoacoustic imaging capabilities were validated using an atherosclerosis-mimicking phantom. Furthermore, we demonstrated high-contrast volumetric in vivo photoacoustic imaging of rodent abdominal vasculature and quantified vessel reactivity due to hypercapnia stimulation. The multiparametric functional and molecular imaging capabilities of the PLD-PAUS system holds promise for POC applications.

The role of transcription factors in the pathogenesis and therapeutic targeting of vascular diseases.

Transcription factors (TFs) constitute an essential component of epigenetic regulation. They contribute to the progression of vascular diseases by regulating epigenetic gene expression in several vascular diseases. Recently, numerous regulatory mechanisms related to vascular pathology, ranging from general TFs that are continuously activated to histiocyte-specific TFs that are activated under specific circumstances, have been studied. TFs participate in the progression of vascular-related diseases by epigenetically regulating vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs). The Krüppel-like family (KLF) TF family is widely recognized as the foremost regulator of vascular diseases. KLF11 prevents aneurysm progression by inhibiting the apoptosis of VSMCs and enhancing their contractile function. The presence of KLF4, another crucial member, suppresses the progression of atherosclerosis (AS) and pulmonary hypertension by attenuating the formation of VSMCs-derived foam cells, ameliorating endothelial dysfunction, and inducing vasodilatory effects. However, the mechanism underlying the regulation of the progression of vascular-related diseases by TFs has remained elusive. The present study categorized the TFs involved in vascular diseases and their regulatory mechanisms to shed light on the potential pathogenesis of vascular diseases, and provide novel insights into their diagnosis and treatment.

Evolutionary trends and innovations in cardiovascular intervention.

Cardiovascular diseases remain a global health challenge, prompting continuous innovation in medical technology, particularly in Cardiovascular MedTech. This article provides a comprehensive exploration of the transformative landscape of Cardiovascular MedTech in the 21st century, focusing on interventions. The escalating prevalence of cardiovascular diseases and the demand for personalized care drive the evolving landscape, with technologies like wearables and AI reshaping patient-centric healthcare. Wearable devices offer real-time monitoring, enhancing procedural precision and patient outcomes. AI facilitates risk assessment and personalized treatment strategies, revolutionizing intervention precision. Minimally invasive procedures, aided by robotics and novel materials, minimize patient impact and improve outcomes. 3D printing enables patient-specific implants, while regenerative medicine promises cardiac regeneration. Augmented reality headsets empower surgeons during procedures, enhancing precision and awareness. Novel materials and radiation reduction techniques further optimize interventions, prioritizing patient safety. Data security measures ensure patient privacy in the era of connected healthcare. Modern technologies enhance traditional surgeries, refining outcomes. The integration of these innovations promises to shape a healthier future for cardiovascular procedures, emphasizing collaboration and research to maximize their transformative potential.

Description of the Characteristics of the Nailfold Capillary Structure in Healthy Children: A Multi-Centric Study.

BACKGROUND: Nailfold videocapillaroscopy (NVC) is the primary diagnostic tool for the assessment of microcirculation in the pediatric population. OBJECTIVE: To define and standardize age-specific normal NVC patterns in healthy children and adolescents. METHODS: A cross-sectional observational multicentric study was conducted in 564 participants aged 5-17 years. Dino-Lite CapillaryScope 200 Pro Model MEDL4N Pro was performed at 200× magnification. Quantitative and qualitative NVC parameters were analyzed separately for each age group and divided into 4 groups based on age categories. RESULTS: Of the 564 healthy participants, 54.9% were female. A total of 1184 images and 3384 capillaries were analysed. Positive correlations were observed between age and capillary density (p < 0.001, R = 0.450, CI95% 0.398-0.503). There was also a positive correlation between age and arterial/venous, loop diameter and capillary length, whereas there was a weak negative correlation between intercapillary distance. However, no correlation was found between age and capillary width. In addition, capillary density was significantly lower in 5-7 age group compared to the other patient groups. Arterial limb diameter was lower in 5-7 age group, while venous limb diameter was significantly wider in 15-17 age group compared to the other patient groups. Dilated capillaries (8.7%), capillary tortuosity (14.4%), crossed capillaries (43.1%), micro-haemorrhages (2.7%), avascular area (4.8%) were present in all age groups. Excellent intra- and interobserver ICC values were obtained for all parameters. CONCLUSION: These findings hold potential significance for future studies, aiding in the analysis and differentiation of children suspected of rheumatological diseases with potential microangiopathy.

The role of pericyte in ocular vascular diseases.

Pericytes are located in the stromal membrane of the capillary outer wall and contain endothelial cells (ECs). They are pivotal in regulating blood flow, enhancing vascular stability, and maintaining the integrity of the blood-retina barrier (BRB)/blood-brain barrier (BBB). The pluripotency of pericytes allows them to differentiate into various cell types, highlighting their significance in vascular disease pathogenesis, as demonstrated by previous studies. This potential enables pericytes to be a potential biomarker for the diagnosis and a target for treatment of vascular disorders. The retina, an essential part of the eyeball, is an extension of cerebral tissue with a transparent refractive medium. It offers a unique window for assessing systemic microvascular lesions. Routine fundus examination is necessary for patients with diabetes and hypertension. Manifestations, such as retinal artery tortuosity, dilation, stenosis, and abnormal arteriovenous anastomosis, serve as typical hallmarks of retinal vasculopathy. Therefore, studies of ocular vascular diseases significantly facilitate the exploration of systemic vascular diseases.

Horizontal mitochondrial transfer as a novel bioenergetic tool for mesenchymal stromal/stem cells: molecular mechanisms and therapeutic potential in a variety of diseases.

Intercellular mitochondrial transfer (MT) is a newly discovered form of cell-to-cell signalling involving the active incorporation of healthy mitochondria into stressed/injured recipient cells, contributing to the restoration of bioenergetic profile and cell viability, reduction of inflammatory processes and normalisation of calcium dynamics. Recent evidence has shown that MT can occur through multiple cellular structures and mechanisms: tunneling nanotubes (TNTs), via gap junctions (GJs), mediated by extracellular vesicles (EVs) and other mechanisms (cell fusion, mitochondrial extrusion and migrasome-mediated mitocytosis) and in different contexts, such as under physiological (tissue homeostasis and stemness maintenance) and pathological conditions (hypoxia, inflammation and cancer). As Mesenchimal Stromal/ Stem Cells (MSC)-mediated MT has emerged as a critical regulatory and restorative mechanism for cell and tissue regeneration and damage repair in recent years, its potential in stem cell therapy has received increasing attention. In particular, the potential therapeutic role of MSCs has been reported in several articles, suggesting that MSCs can enhance tissue repair after injury via MT and membrane vesicle release. For these reasons, in this review, we will discuss the different mechanisms of MSCs-mediated MT and therapeutic effects on different diseases such as neuronal, ischaemic, vascular and pulmonary diseases. Therefore, understanding the molecular and cellular mechanisms of MT and demonstrating its efficacy could be an important milestone that lays the foundation for future clinical trials.

Ferumoxytol-enhanced MR venography for mapping lower-extremity venous networks and evaluating varicose veins in patients with diabetes.

OBJECTIVES: Comprehensive evaluation of lower-extremity varicose veins (VVs) in patients with diabetes is crucial for treatment strategizing. The study aims to assess the feasibility of using ferumoxytol-enhanced MR venography (FE-MRV) for lower-extremity venous mapping and the detection of VVs in patients with diabetes. MATERIALS AND METHODS: As part of a phase II clinical trial of a generic brand of ferumoxytol, documented patients with diabetes were enrolled and underwent FE-MRV on a 3-Τ MRI system. Two observers assessed FE-MRV images for image quality, signal intensity ratio (SIR), perforator (PV) diameter, and luminal signal uniformity in deep-to-superficial venous networks with the assessment of intra- and inter-rater reliability. FE-MRV was used to detect lower-extremity VVs. RESULTS: Eleven patients underwent FE-MRV without adverse events. The average image quality, as scored by the two observers who assessed 275 venous segments, was 3.4 ± 0.6. Two observers strongly agreed on image quality (κ = 0.90) and SIR measurements (interclass correlation coefficient [ICC]: 0.72) and had good agreement on PV diameter (ICC: 0.64). FE-MRV revealed uniform luminal signals in deep and saphenous venous networks (0.13 ± 0.05 vs 0.08 ± 0.03). Below-knee segments exhibited a significantly higher heterogeneity index than above-knee (p = 0.039) segments. Superficial VVs were observed in 55% (12/22) of legs in 64% (7/11) of patients. Calf muscle VVs were present in 64% (14/22) of legs in 9 patients. CONCLUSION: FE-MRV safely and robustly mapped entire lower-extremity venous networks, enabling the detection and pre-treatment evaluation of both superficial, and deep VVs in patients with diabetes. CLINICAL RELEVANCE STATEMENT: Ferumoxytol-enhanced magnetic resonance venography offers a "one-stop" imaging strategy for the detection and pre-operative evaluation of both superficial and deep VVs in diabetic patients. KEY POINTS: Diabetic patients with VVs are at a higher risk of ulcer-related complications. FE-MRV allowed rapid and comprehensive visualization of the lower-limb venous networks and abdominopelvic veins in diabetic patients. This technique allowed for the detection of superficial and deep VVs in diabetic patients before the development of severe peripheral artery disease.

Systemic correlates of cutaneous manifestations of lupus erythematosus.

BACKGROUND: We aimed to investigate the prevalence of skin disease among patients with systemic lupus erythematosus (SLE) and determine whether LE skin disease had clinical or serologic correlates with SLE. METHODS: We reviewed records of 335 patients with SLE (seen at Mayo Clinic, Rochester, Minnesota, USA) and abstracted skin manifestations, fulfilled mucocutaneous SLE criteria, and clinical and serologic parameters. RESULTS: Of the 231 patients with skin manifestations, 57 (24.7%) had LE-specific conditions, 102 (44.2%) had LE-nonspecific conditions, and 72 (31.2%) had both. LE skin disease was associated with photosensitivity, anti-Smith antibodies, and anti-U1RNP antibodies (all P < 0.001). Patients without LE skin disease more commonly had elevated C-reactive protein levels (P = 0.01). Patients meeting 2-4 mucocutaneous American College of Rheumatology criteria less commonly had cytopenia (P = 0.004) or anti-double-stranded DNA antibodies (P = 0.004). No significant associations were observed for systemic involvement (renal, hematologic, neurologic, and arthritis) when comparing patients with or without LE skin involvement. LE skin involvement was not significantly associated with internal SLE disease flare, number of medications, or overall survival. CONCLUSIONS: LE skin disease commonly occurs in patients with SLE. The presence of LE skin disease had no mitigating impact on the severity of SLE sequelae, disease flares, number of medications, or overall survival.

Are Barriers to Physical Activity Associated With Changing Physical Activity Levels and Sedentary Time in Patients With Peripheral Arterial Disease? A Longitudinal Study.

The aims of the current study were to analyze the association between the barriers to and changes in physical activity levels and sedentary behavior, as well as to examine whether these barriers change over time in patients with peripheral artery disease. In this longitudinal study, we assessed 72 patients (68% men; 65.7 ± 9.2 years). Physical activity was measured over a 7-day period using an accelerometer, and data were collected on time spent in sedentary activities, low-light physical activities, and moderate-to-vigorous physical activities. Personal and environmental barriers to physical activity were collected using yes or no questions. Assessments were repeated in the same patients after 27 months (95% confidence interval [26, 28] months). Most barriers remained stable in these patients; however, those who reported lack of money experienced an increase in sedentary behavior (ß = 392.9 [159.7] min/week, p = .02) and a decrease in low-light physical activity (ß = -372.4 [140.1] min/week, p = .02). These findings suggest that patients with symptomatic peripheral artery disease typically exhibit stable barriers over time, and individuals reporting lack of money demonstrated a decrease in low-light physical activity and an increase in sedentary behavior after 27 months.

Design, synthesis, and evaluation of formylpiperazine analogs of Ferrostatin-1 as novel improved ferroptosis inhibitors.

In this study, a series of new formylpiperazine-derived ferroptosis inhibitors were designed and synthesized based on the structure of a known ferroptosis inhibitor, ferrostatin-1 (Fer-1). The anti-ferroptosis activity of these synthetic compounds in human umbilical vein endothelial cells (HUVECs) induced by Erastin was evaluated. It was found that some of the new compounds, especially compound 26, showed potent anti-ferroptosis activity, as evidenced by its ability to restore cell viability, reduce iron accumulation, scavenge reactive oxygen species, maintain mitochondrial membrane potential, increase GSH levels, decrease LPO and MDA content, and upregulate GPX4 expression. Moreover, compound 26 exhibited superior microsomal stability than Fer-1. The present results suggest that compound 26 is a promising lead compound for the development of new ferroptosis inhibitors for the treatment of vascular diseases.

Exosomes in Vascular/Neurological Disorders and the Road Ahead.

Neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), stroke, and aneurysms, are characterized by the abnormal accumulation and aggregation of disease-causing proteins in the brain and spinal cord. Recent research suggests that proteins linked to these conditions can be secreted and transferred among cells using exosomes. The transmission of abnormal protein buildup and the gradual degeneration in the brains of impacted individuals might be supported by these exosomes. Furthermore, it has been reported that neuroprotective functions can also be attributed to exosomes in neurodegenerative diseases. The potential neuroprotective functions may play a role in preventing the formation of aggregates and abnormal accumulation of proteins associated with the disease. The present review summarizes the roles of exosomes in neurodegenerative diseases as well as elucidating their therapeutic potential in AD, PD, ALS, HD, stroke, and aneurysms. By elucidating these two aspects of exosomes, valuable insights into potential therapeutic targets for treating neurodegenerative diseases may be provided.

Retinal microcirculation: A window into systemic circulation and metabolic disease.

The retinal microcirculation system constitutes a unique terminal vessel bed of the systemic circulation, and its perfusion status is directly associated with the neural function of the retina. This vascular network, essential for nourishing various layers of the retina, comprises two primary microcirculation systems: the retinal microcirculation and the choroidal microcirculation, with each system supplying blood to distinct retinal layers and maintaining the associated neural function. The blood flow of those capillaries is regulated via different mechanisms. However, a range of internal and external factors can disrupt the normal architecture and blood flow within the retinal microcirculation, leading to several retinal pathologies, including diabetic retinopathy, macular edema, and vascular occlusions. Metabolic disturbances such as hyperglycemia, hypertension, and dyslipidemia are known to modify retinal microcirculation through various pathways. These alterations are observable in chronic metabolic conditions like diabetes, coronary artery disease, and cerebral microvascular disease due to advances in non-invasive or minimally invasive retinal imaging techniques. Thus, examination of the retinal microcirculation can provide insights into the progression of numerous chronic metabolic disorders. This review discusses the anatomy, physiology and pathophysiology of the retinal microvascular system, with a particular emphasis on the connections between retinal microcirculation and systemic circulation in both healthy states and in the context of prevalent chronic metabolic diseases.