Retinal Microvascular Function Research Articles

High-intensity interval training in patients with glaucoma (HIT-GLAUCOMA): protocol for a multicenter randomized controlled exercise trial.

Glaucoma stands as a prominent global cause of irreversible blindness and the primary treatment approach involves reducing intraocular pressure (IOP). However, around one-third of patients exhibit disease progression despite effective IOP reduction. Microvascular endothelial function, chronic inflammation, and oxidative stress are known to affect retinal neuronal networks and have been associated with disease severity and progression. Exercise training has the potential to counteract these mechanisms as add-on treatment to usual care. The HIT-GLAUCOMA study will investigate the effects of a 6-month high-intensity interval training (HIIT) on intermediate endpoints such as local retinal microvascular and systemic large artery function, inflammation, and oxidative stress as well as clinical endpoints such as visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology. The study is a multi-center randomized controlled clinical trial in patients with both normal tension and high-tension primary open angle glaucoma. Across two study centers, 128 patients will be enrolled and randomized on a 1:1 basis into an exercise intervention group and a usual care control group. The primary microvascular endpoints are retinal arteriolar and venular flicker light-induced dilation at 6months. The primary endpoint in the systemic circulation is brachial artery flow-mediated dilation at 6months. We hypothesize that exercise therapy will improve retinal microvascular function and thus ocular blood flow in patients with glaucoma. As clinical outcomes, we will investigate the effect of exercise on visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology. HIT-GLAUCOMA is a blueprint trial design to study the effect of exercise training on neurodegenerative and cardiovascular diseases. Importantly, patients are also expected to benefit from improvements in general health and cardiovascular co-morbidities. If proven effective, exercise may offer a new add-on treatment strategy to slow glaucoma progression. The trial is registered at Clinicaltrials.gov under the identifier NCT06058598 and is currently in the recruitment stage.

Retinal microvascular function and incidence and trajectories of clinically relevant depressive symptoms: the Maastricht Study.

Cerebral microvascular dysfunction may contribute to depression via disruption of brain structures involved in mood regulation, but evidence is limited. We investigated the association of retinal microvascular function, a proxy for microvascular function in the brain, with incidence and trajectories of clinically relevant depressive symptoms. Longitudinal data are from The Maastricht Study of 5952 participants (59.9 ± 8.5 years/49.7% women) without clinically relevant depressive symptoms at baseline (2010-2017). Central retinal arteriolar equivalent and central retinal venular equivalent (CRAE and CRVE) and a composite score of flicker light-induced retinal arteriolar and venular dilation were assessed at baseline. We assessed incidence and trajectories of clinically relevant depressive symptoms (9-item Patient Health Questionnaire score ⩾10). Trajectories included continuously low prevalence (low, n = 5225 [87.8%]); early increasing, then chronic high prevalence (early-chronic, n = 157 [2.6%]); low, then increasing prevalence (late-increasing, n = 247 [4.2%]); and remitting prevalence (remitting, n = 323 [5.4%]). After a median follow-up of 7.0 years (range 1.0-11.0), 806 (13.5%) individuals had incident clinically relevant depressive symptoms. After full adjustment, a larger CRAE and CRVE were each associated with a lower risk of clinically relevant depressive symptoms (hazard ratios [HRs] per standard deviation [s.d.]: 0.89 [95% confidence interval (CI) 0.83-0.96] and 0.93 [0.86-0.99], respectively), while a lower flicker light-induced retinal dilation was associated with a higher risk of clinically relevant depressive symptoms (HR per s.d.: 1.10 [1.01-1.20]). Compared to the low trajectory, a larger CRAE was associated with lower odds of belonging to the early-chronic trajectory (OR: 0.83 [0.69-0.99]) and a lower flicker light-induced retinal dilation was associated with higher odds of belonging to the remitting trajectory (OR: 1.23 [1.07-1.43]). These findings support the hypothesis that cerebral microvascular dysfunction contributes to the development of depressive symptoms.

Impaired retinal micro-vascular function in patients with atrial fibrillation

BackgroundCardiovascular (CV) risk factors and CV diseases, in particular heart failure, are strongly associated with impaired microvascular retinal endothelial function. Whether atrial fibrillation (AF) contributes to vascular dysfunction is not clear. Therefore, the aim of this study was to investigate the impact of AF on retinal microvascular function. MethodsIn this study, vascular function was measured non-invasively with flicker-light induced vasodilatation of retinal arterioles (FIDart%). Patients with a history of AF and risk factors for heart failure (HF) or heart failure (n = 69; age 67.9 ± 9.2 years, 71% male, 35% HFrEF, 56% paroxysmal, 25% persistent, 19% permanent AF), as well as age, sex and ejection fraction matched patients with absent history of AF (n = 66; age 63.4 ± 10.6 years, 67% male, 47% HFrEF) were included. Patients with AF were further divided into those with paroxysmal AF (in sinus rhythm – AFSR: n = 38, age 71.4 ± 9.2, 73% male), and those with AF at the time of the study visit. ResultsRetinal microvascular function was impaired in patients with AF compared to patients without AF (FIDart% 1.1% [0.3–2.8] vs. 2.7% [1.3–5.1], p < 0.001). Patients currently in AF have poorer retinal microvascular function (FIDart% 0.8% [0.1–1.9) compared to patients with a history of AF but currently in SR at the time of retinal function measurement (1.5% [0.6–4.9] p = 0.017). In patients with AF, impaired retinal vascular function was independently associated with larger left atrial volume (mean 49.8 ± 18.4), even after correction for confounding factors in different models (SCR = -0. 251 to −0.256, p = 0.035–0.01). ConclusionsAF in patients with heart failure is associated with impaired vascular function, even if currently in sinus rhythm. The association of retinal microvascular dysfunction with left atrial volume, a surrogate for elevated cardiac filling pressures, may further highlight the important interplay between the vasculature and elevated filling pressures in the development of AF.

Retinal Microvascular Dysfunction Occurs Early and Similarly in Mild Alzheimer's Disease and Primary-Open Angle Glaucoma Patients.

To assess the similarities and differences in retinal microvascular function between mild Alzheimer's disease (AD) patients, early-stage primary open angle glaucoma (POAG) patients and healthy controls. Retinal vessel reactivity to flickering light was assessed in 10 AD, 19 POAG and 20 healthy age matched control patients by means of dynamic retinal vessel analysis (DVA, IMEDOS, GmbH, Jena, Germany) according to an established protocol. All patients additionally underwent BP measurements and blood analysis for glucose and lipid metabolism markers. AD and POAG patients demonstrated comparable alterations in retinal artery reactivity, in the form of an increased arterial reaction time (RT) to flicker light on the final flicker cycle (p = 0.009), which was not replicated by healthy controls (p &gt; 0.05). Furthermore, the sequential changes in RT on progressing from flicker one to flicker three were found to differ between healthy controls and the two disease groups (p = 0.001). AD and POAG patients demonstrate comparable signs of vascular dysfunction in their retinal arteries at the early stages of their disease process. This provides support for the concept of a common underlying vascular aetiology in these two neurodegenerative diseases.

Retinal vessel diameters and function in cardiovascular risk and disease.

In the last two decades evidence has gradually accumulated suggesting that the eye may be a unique window for cardiovascular risk stratification based on the assessment of subclinical damage of retinal microvascular structure and function. This can be facilitated by non-invasive analysis of static retinal vessel diameters and dynamic recording of flicker light-induced and endothelial function-related dilation of both retinal arterioles and venules. Recent new findings have made retinal microvascular biomarkers strong candidates for clinical implementation as reliable risk predictors. Beyond a review of the current evidence and state of research, the article aims to discuss the methodological benefits and pitfalls and to identify research gaps and future directions. Above all, the potential use for screening and treatment monitoring of cardiovascular disease risk are highlighted. The article provides fundamental comprehension of retinal vessel imaging by explaining anatomical and physiological essentials of the retinal microcirculation leading to a detailed description of the methodological approach. This allows for better understanding of the underlying retinal microvascular pathology associated with the prevalence and development of cardiovascular disease. A body of new evidence is presented on the clinical validity and predictive value of retinal vessel diameters and function for incidence cardiovascular disease and outcome. Findings in children indicate the potential for utility in childhood cardiovascular disease prevention, and the efficacy of exercise interventions highlight the treatment sensitivity of retinal microvascular biomarkers. Finally, coming from the availability of normative data, solutions for diagnostic challenges are discussed and conceptual steps towards clinical implementation are put into perspective.

Retinal Microvascular Abnormalities and Systemic Arterial Stiffness Are the First Manifestation of Cardiovascular Abnormalities in Patients with Untreated Moderate to Severe Obstructive Sleep Apnoea and with Low to Intermediate Cardiovascular Risk-A Pilot Study.

This study aimed to investigate macro- and microvascular function parameters and their relationship with known markers of cardiovascular risk in patients with untreated moderate to severe obstructive sleep apnoea (OSA). Fourteen patients with moderate to severe OSA and fourteen controls were included in the present study. General assessments included BMI, systemic blood pressure (BP) and circulating markers for oxidative stress and endothelial function. Additional assessments included 24 h BP and heart rate monitoring, as well as the assessment of heart rate variability. Macro- and microvascular assessments included augmentation index, carotid intima-media thickness, brachial artery flow-mediated dilation, as well as various retinal microvascular function assessments, using the Dynamic Retinal Vessel Analyzer. All participants completed the Short Form Health Survey, Functional Outcomes of Sleep Questionnaire, and Epworth Sleepiness Scale. The results show that, in comparison to controls, BMI (p = 0.003) and AIx (p = 0.025) were significantly higher in the OSA group. There was, however, no significant difference between groups with regard to other measured systemic general, vascular and circulatory parameters (all p > 0.05). Nevertheless, the retinal microvascular function showed various alterations in the OSA patients, including a delayed reaction time in response to flicker (p = 0.047), as well as a decreased dilation amplitude (p = 0.004), dilation slope (p = 0.004), and post-flicker constriction (p = 0.015). In addition, the observed SlopeAD alterations correlated negatively with BMI values only in the OSA group (r = −0.46, p = 0.045). In conclusion, individuals with untreated moderate to severe OSA but without overt CVD, exhibit signs of increased arterial stiffness and retinal microvascular dysfunction, which can be early indicators for future vascular complications.

The Use of Retinal Microvascular Function and Telomere Length in Age and Blood Pressure Prediction in Individuals with Low Cardiovascular Risk.

Ageing represents a major risk factor for many pathologies that limit human lifespan, including cardiovascular diseases. Biological ageing is a good biomarker to assess early individual risk for CVD. However, finding good measurements of biological ageing is an ongoing quest. This study aims to assess the use retinal microvascular function, separate or in combination with telomere length, as a predictor for age and systemic blood pressure in individuals with low cardiovascular risk. In all, 123 healthy participants with low cardiovascular risk were recruited and divided into three groups: group 1 (less than 30 years old), group 2 (31–50 years old) and group 3 (over 50 years old). Relative telomere length (RTL), parameters of retinal microvascular function, CVD circulatory markers and blood pressure (BP) were measured in all individuals. Symbolic regression- analysis was used to infer chronological age and systemic BP measurements using either RTL or a combination of RTL and parameters for retinal microvascular function. RTL decreased significantly with age (p = 0.010). There were also age-related differences between the study groups in retinal arterial time to maximum dilation (p = 0.005), maximum constriction (p = 0.007) and maximum constriction percentage (p = 0.010). In the youngest participants, the error between predicted versus actual values for the chronological age were smallest in the case of using both retinal vascular functions only (p = 0.039) or the combination of this parameter with RTL (p = 0.0045). Systolic BP was better predicted by RTL also only in younger individuals (p = 0.043). The assessment of retinal arterial vascular function is a better predictor than RTL for non-modifiable variables such as age, and only in younger individuals. In the same age group, RTL is better than microvascular function when inferring modifiable risk factors for CVDs. In older individuals, the accumulation of physiological and structural biological changes makes such predictions unreliable.

Retinal microvascular function is associated with the cerebral microcirculation as determined by intravoxel incoherent motion MRI

Background and aimsThe easily accessible retinal vessels provide a unique opportunity to study a proxy for cerebral small vessels. Associations between retinal vessel diameters and macrostructural brain white matter changes have already been demonstrated. Alterations in microvascular function, likely precede these structural abnormalities. We examined whether retinal microvascular function is related to cerebral microvascular properties, assessed by the intravoxel incoherent motion (IVIM) effect in brain MRI. MethodsSeventy participants (age 60 ± 8 years, 41% women) from the population-based Maastricht Study underwent brain IVIM diffusion imaging (3 Tesla) to determine the microvascular measures f (perfusion volume fraction) and D* (pseudo-diffusion of circulating blood). The retinal arteriolar and venular dilation response to flicker light stimulation were measured by a dynamic vessel analyzer. Linear regression analysis was used to investigate associations between retinal vasoreactivity and IVIM measures in white matter hyperintensities (WMH), normal-appearing white matter (NAWM) and cortical gray matter (CGM). ResultsMore retinal arteriolar dilation was significantly associated with stronger pseudo-diffusion (D*) in the NAWM and CGM (β 0.280 [95% CI 0.084–0.475], and β 0.310 [95% CI 0.091–0.528], respectively), but not with the cerebral blood volume fraction (f). No associations were observed between retinal venular dilation response and cerebrovascular IVIM measures. ConclusionsVariations in retinal arteriolar microvascular function and microcirculatory properties in the brain are linked. The retina could serve as a proxy for early detection of brain microvascular dysfunction.

Cognitive impairment and microvascular function in end-stage renal disease.

ObjectiveHemodialysis patients show an approximately threefold higher prevalence of cognitive impairment compared to the age‐matched general population. Impaired microcirculatory function is one of the assumed causes. Dynamic retinal vessel analysis is a quantitative method for measuring neurovascular coupling and microvascular endothelial function. We hypothesize that cognitive impairment is associated with altered microcirculation of retinal vessels.Methods152 chronic hemodialysis patients underwent cognitive testing using the Montreal Cognitive Assessment. Retinal microcirculation was assessed by Dynamic Retinal Vessel Analysis, which carries out an examination recording retinal vessels' reaction to a flicker light stimulus under standardized conditions.ResultsIn unadjusted as well as in adjusted linear regression analyses a significant association between the visuospatial executive function domain score of the Montreal Cognitive Assessment and the maximum arteriolar dilation as response of retinal arterioles to the flicker light stimulation was obtained.ConclusionThis is the first study determining retinal microvascular function as surrogate for cerebral microvascular function and cognition in hemodialysis patients. The relationship between impairment in executive function and reduced arteriolar reaction to flicker light stimulation supports the involvement of cerebral small vessel disease as contributing factor for the development of cognitive impairment in this patient population and might be a target for noninvasive disease monitoring and therapeutic intervention.

Effect of obstructive sleep apnoea on retinal microvascular function: a randomised controlled trial

PurposeRetinal microvascular endothelial dysfunction is thought to be of importance in the development of ocular vascular diseases. Obstructive sleep apnoea (OSA) causes macrovascular endothelial dysfunction, but the effect of OSA on retinal microvascular endothelial function is not known. We aimed to determine the effect of OSA on retinal microvascular function.MethodsWe conducted a multi-centre, double-blind, randomised, parallel, controlled trial in patients with known moderate-to-severe OSA, established on continuous positive airway pressure (CPAP). Participants were randomised to 14 nights of either continued CPAP or sham CPAP to generate a return of OSA. Retinal vascular responses to flickering light were measured using dynamic vessel analysis both at baseline and after 14 nights of intervention. The primary outcome was the change from baseline to follow-up in the area under the curve of the arteriolar response to flickering light, sham CPAP versus continued CPAP.ResultsNineteen patients were randomised to sham CPAP, and 18 patients were randomised to continued CPAP. There was no significant effect of CPAP withdrawal and return of OSA on retinal responses, with a change in the area under the curve of the arteriole response to flickering light of + 3.8 arbitrary units (95% CI − 10.6 to + 18.2, p = 0.59), sham CPAP versus continued CPAP.ConclusionsCPAP withdrawal and a return of OSA had no significant effect on retinal microvascular responses. This contrasts with the effect of CPAP withdrawal on macrovascular endothelial function and suggests that OSA has different effects on macrovascular and microvascular endothelial function.ISRCTN 78082983, 23/10/2014, Prospectively registered.

Oxysterols and Retinal Microvascular Dysfunction as Early Risk Markers for Cardiovascular Disease in Normal, Ageing Individuals.

The aim of the present paper is to assess the relationship between oxysterol levels and retinal microvascular function in individuals of various age groups, free of clinically evident diseases. Forty-two apparently healthy individuals were included in the present study (group 1: 19–30 years, group 2: 31–50 years, and group 3: 51–70 years). Retinal microvascular function was assessed using the dynamic retinal vessel analyzer (DVA, IMEDOS GmbH, Jena, Germany). Fasting plasma was obtained from all subjects and quantification of monohydroxy and dihydroxy oxysterols assessment was performed using LC-MS/MS following reverse phase chromatography. A Griess assay was used to evaluate the Nitric Oxide (NO) concentration in all individuals. The glutathione redox ratio was also analyzed by means of whole blood glutathione recycling assay. In all participants, the levels of 7-Ketocholesterol, 25-hydroxycholesterol and 7β-hydroxycholesterol correlated significantly and positively with the time to maximum arteriolar dilation. In addition, 25-hydroxycholesterol and 7β-hydroxycholesterol negatively correlated to the percentage of maximum arteriolar dilation. A negative correlation was observed for 27-hydroxycholesterol and 7β-hydroxycholesterol with microvascular arteriolar constriction. These results suggest that, with age, abnormal oxysterol levels correlate with early changes in microvascular bed function. This relationship could signal early risk for cardiovascular diseases (CVDs) in an ageing population.

Retinal microvascular function predicts chronic kidney disease in patients with cardiovascular risk factors

Background and aimsEndothelial dysfunction is a precursor to atherosclerosis and is implicated in the coexistence between cardiovascular disease (CVD) and chronic kidney disease (CKD). We examined whether retinal microvascular dysfunction is present in subjects with renal impairment and predictive of long-term CKD progression in patients with CVD. MethodsIn a single centre prospective observational study, 253 subjects with coronary artery disease and CVD risk factors underwent dynamic retinal vessel analysis. Retinal microvascular dysfunction was quantified by measuring retinal arteriolar and venular dilatation in response to flicker light stimulation. Serial renal function assessment was performed over a median period of 9.3 years using estimated GFR (eGFR). ResultsFlicker light-induced retinal arteriolar dilatation (FI-RAD) was attenuated in patients with baseline eGFR <90 mL/min/1.73 m2, compared to those with normal renal function (eGFR ≥90 mL/min/1.73 m2) (1.0 [0.4–2.1]% vs. 2.0 [0.8–3.6]%; p < 0.01). In patients with normal renal function, subjects with the lowest FI-RAD responses exhibited the greatest annual decline in eGFR. In uni- and multivariable analysis, among subjects with normal renal function, a 1% decrease in FI-RAD was associated with an accelerated decline in eGFR of 0.10 (0.01, 0.15; p = 0.03) and 0.07 mL/min/1.73 m2 per year (0.00, 0.14; p = 0.06), respectively. FI-RAD was not predictive of CKD progression in subjects with baseline eGFR <90 mL/min/1.73 m2. ConclusionsRetinal arteriolar endothelial dysfunction is present in patients with CVD who have early-stage CKD, and serves as an indicator of long-term CKD progression in those with normal renal function.

Improvement of retinal microvascular function after initiation of lipid-lowering therapy with PCSK9 inhibitors – an observational study

Abstract Background Hypercholesterolemia is associated with endothelial dysfunction. While good evidence exists for the beneficial endothelial effects of first-line lipid-lowering drugs (statins), less is known on the new class of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. This is particularly true for the differential effects on micro- and macrovascular endothelial function and arterial stiffness. Purpose The goal of this study was to study the change in retinal microvascular dysfunction, brachial artery endothelial function and arterial stiffness in high-risk cardiovascular risk patients before and after initiation of PCSK9 inhibitor therapy with alirocumab or evolocumab. Methods In this prospective observational study, cardiovascular high-risk patients with a clinical indication for PCSK9 inhibitors were included for the measurement of retinal microvascular function (flicker light-induced dilatation of retinal arterioles and venules, FIDart and FIDven respectively; retinal arteriovenous ratio, AVR), brachial artery flow-mediated dilatation (FMD) and arterial stiffness (pulse wave velocity, PWV; augmentation index, AI). Measurements were performed at baseline, after 3 months and after 12 months of PCSK9 inhibitor therapy. The primary endpoint was the change in FIDart after 12 months of therapy compared to baseline. Results We recruited 48 patients (mean age 57±11 years, 27% female, 81% coronary artery disease) which began treatment with alirocumab or evolocumab in our lipid outpatient clinic. 6 patients were excluded from the analysis (n=3 stopped due to side effects, n=1 stopped due to new metastatic cancer, n=1 moved abroad, n=1 no retinal vessel analysis possible). LDL cholesterol was reduced from 3.8±1.2 to 1.5±0.8 and 1.8±0.9 mmol/L at 3 and 12 months respectively (all p&amp;lt;0.001). There was no significant change in systolic blood pressure during therapy. The primary endpoint FIDart was significantly increased after 12 months of PCSK9 inhibitor therapy compared to baseline (3.4±2.3 vs. 2.6±1.6%, p=0.01). Among the secondary endpoints, augmentation index improved at 12 months vs. baseline (21±12 vs. 24±9%, p=0.03). No significant change was seen for FIDven, AVR, FMD and PWV after 3 and 12 months of therapy. Conclusion In cardiovascular high-risk patients, PCSK9 inhibition is associated with an improvement of retinal microvascular function and augmentation index after one year of therapy. No effects were seen for macrovascular parameters such as FMD or PWV in our cohort. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): University Hospital Zurich, AGLA Grant (sponsored by Amgen)

Retinal microvascular and neuronal function in patients with multiple sclerosis: 2-year follow-up

Objective: To determine the longitudinal changes in retinal microstructure, microvasculature, microcirculation, and axonal and neuronal functions in patients with relapsing-remitting multiple sclerosis (RRMS) over the time course of about two years.Methods: A total of 30 patients (60 eyes) with RRMS were followed for a period of 27 ± 6 months and evaluated with a battery of clinical tests including low contrast letter acuity (LCLA), intraretinal layer thicknesses by optical coherence tomography (OCT), ganglion cell function by steady-state pattern electroretinography (PERG), axonal function by polarization-sensitive OCT, volumetric vessel density (VVD) by OCT angiography, and retinal tissue perfusion (RTP) by retinal function imager.Results: Axonal function measured as retinal nerve fiber layer birefringence in the temporal quadrant and vessel density in the deep vascular plexus were significantly decreased at 2-year follow-up (P < 0.05). Subgroup analyses showed that the increased retinal blood flow volume occurred in patients with no evidence of disease activity (NEDA), and with stable or improved visual function (P < 0.05). There was no significant difference in the expanded disability state scale, LCLA, RTP, VVD, or PERG measures between the two visits (P > 0.05).Conclusion: To our best knowledge, this is the first 2-year prospective comprehensive study with a detailed assessment of retinal microstructure and neuronal functions in patients with RRMS. The recovery of retinal microcirculation occurred in patients with NEDA, and stable or improved visual function, suggesting these measurements as potential imaging biomarkers for monitoring disease progression.

Vascular ophthalmopathies - an interdisciplinary task

Retinal microvascular function is highly depending on macrovascular circulation and especially on blood pressure variability and nocturnal blood pressure. The eyes are more subject to central hemodynamics compared to peripheral pressures. Pulse wave analysis is essential here and can reveal masked aortic hypertension. Morphological and functional changes of retinal vessels are detected today in high resolution by digital imaging techniques. Early hypertensive changes can be visualized best by laser scanning multi-color devices, and the vessel diameters (AV-Ratio) are measured precisely by static vessel analysis. Functional disorders of vascular motility are delineated reproducibly by devices for dynamic vessel analysis. Also functional effects of cardiovascular therapy measures can be judged by these means: micro- meets macrocirculation.

Dry eye disease is associated with retinal microvascular dysfunction and possible risk for cardiovascular disease.

To explore the presence of microvascular endothelial dysfunction as a measure for early cardiovascular disease in individuals diagnosed with dry eye disease (DED) as compared to age-matched normal controls. Systemic blood pressure, Body Mass Index, intraocular pressure, blood levels of glucose (GLUC), triglycerides, cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)] as well as retinal and peripheral microvascular function were assessed in twenty-five 35-50year olds with diagnosed with DEDa (using the TFOS DEWS II criteria) and 25 age and sex-matched controls. After controlling all the influential covariates, individuals diagnosed with DED exhibited significant lower retinal artery baseline (p=0.027), artery maximum diameter (p=0.027), minimum constriction (p=0.039) and dilation amplitude (p=0.029) than controls. In addition, the time to reach the vein maximum diameter was significantly longer in the DED patients than in normal controls (p=0.0052). Only in individuals diagnosed with DED, artery maximum constriction correlated statistically significantly and positively with HDL-C blood levels (p=0.006). Similarly, artery slopeAD correlated positively with T-CHOL and LDL-C (p=0.006 & 0.011 respectively). Additionally, artery baseline diameter and maximum constriction were significantly and negatively correlated to T-CHOL/HDL-C ratio (p=0.032 and p=0.013 respectively) in DED individuals only. Individuals with positive diagnosis of DED exhibit abnormal retinal microvascular function and possible higher risk for CVD.

European Society of Cardiology/European Society of Hypertension versus the American College of Cardiology/American Heart Association guidelines on the cut-off values for early hypertension: a microvascular perspective

The aim of this study was to investigate retinal and peripheral microvascular function in asymptomatic individuals that fall into different BP groups when using either the ESC/ESH or the ACC/AHA guidelines. Retinal and peripheral microvascular function was assessed in 358 participants by means of dynamic retinal vessel analysis and digital thermal monitoring, respectively. Blood pressure and lipid panel were also evaluated. Retinal vascular function measured in all groups belonging to the ACC/ASH classifications were within the normal values for age-matched normal population. Individuals classed as grade 1 hypertension according to the ESC/ESH guidelines, however, exhibited a significantly decreased artery baseline (p = 0.0004) and MC (p = 0.040), higher slopeAD (p = 0.0018) and decreased vein MC (p = 0.0446) compared to age matched normal individuals. In addition, they also had significant lower artery baseline, artery BDF, MD and MC than individuals classed as stage 1 hypertension based on the ACC/ASH guidelines (p = 0.00022, p = 0.0179, p = 0.0409 and p = 0.0329 respectively). Peripheral vascular reactivity (aTR) was lower in ESC /ESH grade I compared to those graded ACC/ASH stage I hypertension (p = 0.0122). The conclusion of this study is that microvascular dysfunctions is present at multiple levels only in individuals with ESC/ESH grade 1 hypertension. This observation could be important when deciding personalised care in individuals with early hypertensive changes.

Retinal Microvascular Endothelial Function is Impaired in Subjects With Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is a common sleep-related breathing disorder associated with major adverse cardiovascular events (MACE). Endothelial dysfunction is a silent precursor to atherosclerosis and a proposed mechanistic link between OSA and consequent cardiovascular risk. We examined whether retinal microvascular endothelial dysfunction is impaired in subjects with OSA and predictive of long-term MACE.

Retinal Microvascular Endothelial Function is Impaired in Subjects With Chronic Kidney Disease

Endothelial dysfunction is a sentinel precursor to atherosclerosis and is implicated in the common coexistence between cardiovascular disease (CVD) and chronic kidney disease (CKD). We examined whether retinal microvascular endothelial dysfunction is present in subjects with CKD and further predictive of long-term CKD progression.

Association between Light-Induced Dynamic Dilation of Retinal Vessels and Echocardiographic Parameters of the Left Ventricular Function in Hypertensive Patients.

Background and Objectives: The goal was to evaluate the association of dynamic retinal vessel analysis (DVA) with echocardiographic parameters assessing systolic and diastolic function of the left ventricle in hypertension (HT) patients with preserved left ventricle ejection fraction. Materials and Methods: This observational retrospective study recruited 36 patients with HT and 28 healthy controls. Retinal vessel diameter and reactions to flicker light were examined. Each patient was examined with echocardiography to assess left ventricular systolic and diastolic function. Results: Multivariate analysis revealed that hypertension was an independent factor associated with lower flicker-induced arterial vasodilatation (β = −0.31, p = 0.029). In the HT group, there was a significant positive association between left ventricular ejection fraction and flicker-induced arterial vasodilation (Rs = +0.31, p = 0.007). Additionally, end-diastolic left ventricular diameter negatively correlated with both arterial (Rs = −0.26, p = 0.02) and venous (Rs = −0.27, p = 0.02) flicker responses. Additionally, the echocardiographic characteristics of the left atrium (LA) remodeling in the course of HT, including the area of the LA and its antero-posterior dimension, were both negatively correlated with the arterial flicker response (Rs = −0.34, p = 0.003; Rs = −0.33, p = 0.004, respectively). From tissue Doppler parameters, the left ventricular filling index E/e’ negatively correlated with AVR (arteriovenous ratio) values (Rs = −0.36, p = 0.002). Conclusions: We revealed that systolic and diastolic function of the left ventricle in hypertensive patients is associated with retinal microvascular function.