Are retinal microvascular abnormalities associated with large artery endothelial dysfunction and intima-media thickness? The Hoorn Study

Comparative analysis of retinal microvascular parameters in healthy individuals with or without carotid artery stenosis or plaque

PurposeTo evaluate the correlations between retinal microvascular changes and carotid artery stenosis (CAS) with and without plaques using fundus photography.MethodsPatients who had undergone bilateral carotid ultrasonography and bilateral fundus photography were divided into the following groups based on the carotid intima-media thickness (IMT) determined via ultrasonography in this retrospective, observational study: the control and CAS (comprising CAS with and without plaque subgroups) groups. The following retinal indicators were determined via fundus photography based on a deep learning algorithm: the arteriole-to-venule ratio (AVR), whole retinal fractal dimension (FD), arteriolar fractal dimension (AFD), venular fractal dimension (VFD), vascular density (VD), and VD within 3 mm (VD3mm) and 5 mm (VD5mm) from the macular fovea. The correlations between these indicators and IMT were also assessed.ResultsIn total, 715 participants, comprising 313 participants with CAS (CAS group; 91 with plaque and 222 without plaque) and 402 participants without CAS (control group), participated in this study. AFD, VFD, and FD in the CAS group were significantly lower than those in the control group (all p < 0.001). VD, VD3mm, and VD5mm showed significant differences between the groups (all p < 0.05). VFD in the CAS with plaque group was lower than that in the group without plaque (p = 0.014). VD3mm, and VD5mm showed significantly negative correlations with IMTmin in the CAS subgroup.ConclusionsAFD, VFD, FD, VD, VD3 mm, and VD5 mm decreased, and fundus photography based on deep learning algorithm may provide new approaches for screening of CAS.

The impact of serum BNP on retinal perfusion assessed by an AI-based denoising optical coherence tomography angiography in CHD patients

Background

To investigate the correlation between retinal vessel density (VD) parameters with serum B-type natriuretic peptide (BNP) in patients with coronary heart disease (CHD) using novel optical coherence tomography angiography (OCTA) denoising images based on artificial intelligence (AI).

Methods

OCTA images of the optic nerve and macular area were obtained using a Canon-HS100 OCT device in 176 patients with CHD. Baseline information and blood test results were recorded.

Results

Retinal VD parameters of the macular and optic nerves on OCTA were significantly decreased in patients with CHD after denoising. Retinal VD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillary (RPC) was strongly correlated with serum BNP levels in patients with CHD. Significant differences were noted in retinal thickness and retinal VD (SCP, DCP and RPC) between the increased BNP and normal BNP groups in patients with CHD.

Conclusion

Deep learning denoising can remove background noise and smooth rough vessel surfaces. SCP,DCP and RPC may be potential clinical markers of cardiac function in patients with CHD. Denoising shows great potential for improving the sensitivity of OCTA images as a biomarker for CHD progression.

Sex-specific association between carotid atherosclerosis and fundus arteriosclerosis in a Chinese population: a retrospective cross-sectional study

OBJECTIVES

Vascular stiffening is highly predictive of major adverse cardiovascular events. It is not clear whether microangiopathy, such as fundus arteriosclerosis, is related to carotid atherosclerosis. Hence, this study was designed to investigate the relationship between carotid atherosclerosis and fundus arteriosclerosis among individuals of different sexes in the Chinese health-examination population.

METHODS

This retrospective cross-sectional study involved 20,836 participants, including 13050 males and 7786 females. All participants underwent a detailed health examination, including medical history assessment, physical examination, assessment of lifestyle factors, fundus photography, Doppler ultrasound examination of the neck, and laboratory examinations. Two trained ophthalmologists analysed fundus arteriosclerosis based on fundus photographs, while carotid atherosclerosis was diagnosed using colour Doppler sonography of the neck. Binary logistic regression was used to analyse the relationship between carotid atherosclerosis and fundus arteriosclerosis.

RESULTS

In participants with fundus arteriosclerosis, the incidence of carotid atherosclerosis was higher than that of participants without fundus arteriosclerosis (52.94% vs. 47.06%). After adjustments for potential confounding factors, fundus arteriosclerosis was significantly associated with the risk of carotid atherosclerosis. The OR with 95% CI for fundus arteriosclerosis was 1.17 (1.02, 1.34) with p = 0.0262, and individuals who did not have fundus arteriosclerosis were used as a reference in the total population. Fundus arteriosclerosis was associated with the incidence of carotid atherosclerosis in males (p = 0.0005) but not in females (p = 0.0746).

CONCLUSIONS

Fundus arteriosclerosis was closely associated with carotid atherosclerosis in the Chinese population. This association was found in males but not in females.

Association of microvascular biomarkers in fluorescein angiography with macrovascular-related mortality in clinical routine data

Purpose

Early detection of microvascular changes in the retina may be important for the risk assessment of cardiovascular health. Therefore, the purpose of this study was to investigate imaging biomarkers in fluorescein angiography (FA) as potential predictors for cardiovascular mortality.

Methods

In this retrospective, matched case-control study, we included FA images from clinical routine data between 2007 and 2018 of 100 patients who died of macrovascular events (Group 1) and 100 age- and sex-matched controls (Group 2). All patients were under treatment for different, mostly retinal, ocular diseases. FA images were used for the measurement of the foveal avascular zone (FAZ) and the arteriolar and venular caliber.

Results

Patients mean age on examination day was 69.5 ± 8.3 years with a 1:1 female:male subject ratio. Mean FAZ area of our sample was 0.340 ± 0.135 mm² for Group 1 and 0.264 ± 0.137 mm² for Group 2 (P < 0.001), showing a larger FAZ area in patients who subsequently died of macrovascular-related systemic diseases.

Conclusions

Individuals effected by a macrovascular-related disease show a larger FAZ on FA examinations before the event compared to patients which are unaffected. Our results highlight a possible role of the FAZ as additional biomarker for the cardiovascular condition.

Retinal changes in patients with angina pectoris and anginal equivalents: a study of patients with normal coronary angiography

Background and aims. Approximately 10-30% of the patients with typical symptoms of angina pectoris have normal angiography showing normal macrovasculature. In these patients, however, the microvascular problems should be monitored. Hence, the main aim of this study is to evaluate retinal changes in normal angiographic patients.Methods. In this descriptive cross-sectional study, 60 normal angiographic patients with typical chest pain or anginal equivalents visiting Modarres Hospital Cardiology Research Center between 2018 and 2019 were enrolled and retinal changes were determined in Labbafinejad Hospital by Optical Coherence Tomography Angiography using Foveal Avascular Zone (FAZ), Superficial Vascular Density (SVD), and Deep Vascular Density (DVD).Results. The results of this study demonstrated that FAZ was normal in all subjects, but SVD and DVD were abnormal in 45% and 8.3%, respectively. Totally, 18.5% and 66.7% showed abnormal SVD among stable angina (SA) and unstable angina (UA) cases, respectively (P < 0.001). There was no statistically significant difference between abnormal DVD in SA and UA cases (P = 0.058). Abnormal SVD was significantly more common among diabetic patients (P < 0.001), while DVD was not related to diabetes presence in the study population (P > 0.05). Moreover, abnormal SVD was more common among patients with chest pain (P = 0.036), while there was no significant difference for DVD (P = 0.371). Interestingly, abnormal ECG was associated with both abnormal DVD and SVD.Conclusions. The results of this study showed that nearly half of the patients with angina pectoris or anginal equivalents who revealed normal angiographic findings may suffer from retinal changes. Thus, retinal assessment is needed in these patients to evaluate microvascular changes.

Positive relationship of hypertensive retinopathy with carotid intima--media thickness in hypertensive patients

OBJECTIVES

We aimed to explore the relationship of hypertensive retinopathy with carotid intima--media thickness (CIMT), and to examine the possible effect modifiers in Chinese adults with hypertension.

METHODS

We conducted a cross-sectional study of 12 342 hypertensive patients with complete exit site visit data from the China Stroke Primary Prevention Trial. CIMT was measured by carotid ultrasonography. Hypertensive retinopathy was diagnosed according to the Keith--Wagener--Barker classification.

RESULTS

The mean (SD) CIMT among study participants was 739.9 (111.4) μm. Compared with patients with grade 1 hypertensive retinopathy or without hypertensive retinopathy, a significantly higher CIMT level (β, 7.63, 95% CI: 2.54--12.73) was observed in patients with grade 2-4 hypertensive retinopathy. Moreover, the association between hypertensive retinopathy (grade 2-4 versus grade 1 or normal) and CIMT was stronger in participants of younger age (<60 years; β, 13.70, 95% CI: 5.65--21.75; versus ≥60 years; β, 1.03, 95% CI: -5.58 to 7.63; P interaction = 0.006); or with lower total homocysteine levels [<12.1 μmol/l (median); β, 12.70, 95% CI: 5.98--19.42; versus ≥12.1 μmol/l; β, 2.07, 95% CI: -5.63 to 9.78; P interaction = 0.030). None of the other variables, including sex, BMI, study centers, treatment group, SBP, triglycerides, total cholesterol, fasting blood glucose, folate, serum creatinine, current smoking and alcohol drinking, significantly modified the relation of hypertensive retinopathy with CIMT levels.

CONCLUSION

Hypertensive retinopathy (grade 2 and higher) was significantly associated with increased CIMT in hypertensive patients. The association was stronger in those of younger age or with lower total homocysteine levels.

Relation between retinal vessel diameter and posterior segment optical coherence tomography variables in middle-aged Caucasians: the Northern Finland Birth Cohort Eye Study

AIMS

Studying the relationship between retinal vessel diameter (RVD) with (1) macular thickness and volume, (2) retinal nerve fibre layer (RNFL), (3) ganglion cell-inner plexiform layer (GC-IPL) and (4) optic nerve head (ONH) in a population cohort of middle-aged Caucasians.

METHODS

We collected data from 3070 individuals. We used a semiautomated computer-assisted programme to measure central retinal arteriolar equivalent and central retinal venular equivalent. Macular and ONH parameters were assessed by optical coherence tomography.

RESULTS

Data from 2155 persons were analysed. A larger RVD was associated with a thicker macula and increased macular volume; each SD increase in average macular thickness and volume was associated with a 3.28 µm and a 3.19 µm increase in arteriolar diameter and a 5.10 µm and a 5.08 µm increase in venular diameter, respectively (p<0.001 for all). A larger rim area, greater GC-IPL and RNFL thicknesses were associated with larger RVD; each SD increase in rim area, GC-IPL thickness and RNFL thickness was associated with a 1.21 µm, 2.68 µm and a 3.29 µm increase in arteriolar diameter and a 2.13 µm, 4.02 µm and 5.04 µm increase in venular diameter, respectively (p<0.001 for all).

CONCLUSIONS

Increased macular thickness, macular volume, GC-IPL thickness, RNFL thickness and optic nerve rim area were associated with larger RVDs in all subjects. This study clarified the anatomical correlations between both macular and ONH parameters with RVD for middle-aged Caucasians; these can represent a basis for further studies investigating the vascular aetiology of eye diseases.

Association Between Atherosclerosis and Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes Mellitus

AIM

To explore the association between the atherosclerosis and diabetic retinopathy (DR) in Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

This hospital-based cross-sectional study included 949 patients (700 males and 249 females) with T2DM. The atherosclerotic parameters were assessed using the cardio-ankle vascular index (CAVI), ankle-brachial index (ABI), and carotid plaque. DR was assessed and graded using digital retinal photography and fundus fluorescein angiography as either nonproliferative DR (NPDR) or proliferative DR (PDR). Multiple logistic regression analysis was performed to identify the associations between the atherosclerotic parameters and DR status.

RESULTS

The prevalence of DR was 23.6% in total patients, including 167 (17.6%) patients with NPDR and 57 (6.0%) patients with PDR. Patients with NPDR and PDR were more likely to have higher prevalence of increased CAVI, increased ABI, and carotid plaque than those without DR. In multivariable adjusted logistic regression analysis, patients with NPDR showed an odds ratio (OR) of 2.59 [95% confidence interval (CI), 1.61-4.19] for increased CAVI, 1.99 (0.62-6.34) for increased ABI, and 1.75 (1.13-2.71) for carotid plaque. Patients with PDR showed an OR of 7.83 (3.52-17.41) for increased CAVI, 10.65 (3.33-34.04) for increased ABI, and 11.40 (2.67-48.63) for carotid plaque.

CONCLUSION

Both NPDR and PDR were independently associated with increased CAVI and presence of carotid plaque in Chinese patients with T2DM.

Relationship between retinal vessel diameter with both retinal nerve fibre layer thickness and optic nerve head parameters in middle-aged Caucasians: the Northern Finland Birth Cohort Eye study

Purpose

To study the normal relationship between retinal vessel diameter (RVD) with retinal nerve fibre layer (RNFL) thickness and optic nerve head (ONH) parameters in a cohort of middle‐aged Caucasians.

Methods

We investigated 3070 individuals (6140 eyes). Central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were measured in the right eye using a semi‐automated computer‐assisted program. Retinal nerve fibre layer (RNFL) thickness and ONH parameters were assessed with Heidelberg retinal tomography (HRT).

Results

Data from 2217 persons were analysed including RNFL, CRAE, CRVE, sex, body mass index, mean arterial pressure, diabetes status, smoking status, optic disc area, rim area, spherical refraction and intraocular pressure. A larger RVD was associated with a thicker mean global RNFL thickness especially in global and inferior segments of the retina and with larger optic discs. Each 10 μm increase in the retinal arteriolar calibre was associated with a 5.58 μm increase in mean global RNFL thickness; the corresponding value for a 10 μm increase in venular calibre was 3.79 μm (p < 0.001 for both). Retinal venular calibre displayed consistent associations with RNFL thickness in both genders (p < 0.001 for all), whereas the association of arteriolar calibre and RNFL was more prominent in men (p < 0.001).

Conclusion

We found strong associations between larger RVD and thicker RNFL in all subjects. This study helps to clarify the association between RVD, RNFL thickness and ONH parameters and provides normal values for middle‐aged Caucasians that will help in future studies investigating the role of vascular aetiology in systemic and eye diseases.

A full-width half-maximum method to assess retinal vascular structural changes in patients with ischemic heart disease and microvascular anginga

Chest pain patients without obstructive ischemic heart disease (IHD) have increased attention in the clinical practice as carrying higher cardiovascular (CV) risk and impaired life quality. Retinal vasculature is a novel but reliable risk factor of atherosclerosis and systemic vascular diseases. However, the association of retinal blood vessels and unobstructed IHD, as known as microvascular anginga (MA) is poorly understood. This study compared retinal vascular structures of obstructive IHD and MA using spectral domain optical coherence tomography (SD-OCT) and full-width half-maximum (FWHM) methods to provide new risk predictive evidence of MA. Fundus vessels of 120 IHD patients, including 91epicardial IHD and 29 MA patients, and 66 control subjects were evaluated. Significant differences in the retinal arterial lumen diameter (RALD), retinal arterial outer diameter (RAOD), and arteriovenous ratio (AVR) have been found (P < 0.05). The severity of IHD was negatively correlated with diameters of RAOD, RALD and AVR (P < 0.05). In conclusion, there were significant differences in the retinal vascular structure between IHD patients and patients with MA. Thus, assessment of retinal vascular structure is suggested to evaluate CV risk of IHD patients, despite having no obstructive IHD.

Neural dysfunction and retinopathy in persons with type 1 diabetes

OBJECTIVE

To determine associations of microvascular and neuropathic complications of diabetes cross-sectionally and longitudinally in persons with long-term type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

Persons receiving care for T1D in South Central Wisconsin were identified in 1979-1980 and examined approximately every 5 years. Associations between neuropathic and microvascular complications were examined at most prior visits, when information on several neuropathic complications was collected. Temporal relationships were examined by modeling incidence between examinations across the visits.

RESULTS

Adjusting for duration of diabetes, glycated hemoglobin, and systolic blood pressure, the following were cross-sectionally associated with prevalent PDR (proliferative diabetic retinopathy): the presence of sensory neuropathy (SN) as reported at each Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) examination (odds ratio (OR) = 2.76, confidence interval (CI) = 1.71, 4.48) and the heartrate variability measures RMSD (square root of the mean of squared differences of successive RR intervals) (OR = 0.24, CI = 0.16, 0.37) and SDNN (standard deviation of successive RR intervals) (OR = 0.26, CI = 0.17, 0.39). Findings were similar for prevalent ME (macular edema) as assessed from spectral-domain optical coherence tomography (SD-OCT). The presence of PDR (OR = 2.13, CI = 1.63, 2.78) and ME (OR = 2.36, CI = 1.66, 3.34) were both significantly associated with incident WESDR SN. WESDR SN was associated with incident PDR (OR = 1.53, CI = 1.09, 2.15) but not incident ME (OR = 1.31, CI = 0.92, 1.87).

CONCLUSIONS

Sensory neuropathy and heartrate variability were significantly associated with prevalent PDR and ME in people with long-term T1D. PDR and ME were significantly associated with incident sensory neuropathy, and sensory neuropathy was significantly associated with incident PDR. Studies using earliest detectable markers of microvascular and neurologic abnormalities are needed to determine which of the two systems 'fails' first. Such information might suggest a temporal sequence of diabetes complications.

Review of the association between retinal microvascular characteristics and eye disease

Computerized retinal imaging technologies enable the static and dynamic measurement of a range of retinal microvascular parameters. Large population-based studies have reported associations between these microvascular indices and various ophthalmic diseases including diabetes, age-related macular degeneration, retinal artery embolism, retinal vein occlusion, glaucoma and non-glaucomatous optic neuropathies. Increasingly, sophisticated imaging and analysis techniques have the potential to provide relevant clinical information regarding disease risk and progression; however, further studies are required to verify associations and strengthen the predictive power of these techniques. We summarize the current state of knowledge regarding retinal microvascular characteristics and eye disease.

Association Between Blood Pressure and Retinal Vessel Diameters Among Police Officers in the US Northeast

OBJECTIVE

The aim of this study was to examine relationships of blood pressure with central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) among 242 police officers.

METHODS

Computerized retinal images of each eye were taken. Mean values of CRAE and CRVE were compared across hypertension status categories using analysis of variance and analysis of covariance. Associations of mean arterial blood pressure (MABP) with CRAE and CRVE were obtained using regression models.

RESULTS

CRAE was significantly narrower in officers with uncontrolled hypertension (142.8 ± 2.7 μm), compared with those with controlled hypertension (153.6 ± 2.7 μm, P = 0.0013) and those with no hypertension (156.4 ± 1.0 μm, P ≤ 0.0001) after covariate adjustment. CRAE decreased by 3.43 μm for each 5 mm Hg increase in MABP (P ≤ 0.0001).

CONCLUSION

Uncontrolled hypertension was significantly associated with narrower retinal arterioles. No association was observed with retinal venules.

Using Retinal Imaging to Study Dementia

The retina offers a unique "window" to study pathophysiological processes of dementia in the brain, as it is an extension of the central nervous system (CNS) and shares prominent similarities with the brain in terms of embryological origin, anatomical features and physiological properties.  The vascular and neuronal structure in the retina can now be visualized easily and non-invasively using retinal imaging techniques, including fundus photography and optical coherence tomography (OCT), and quantified semi-automatically using computer-assisted analysis programs. Studying the associations between vascular and neuronal changes in the retina and dementia could improve our understanding of dementia and, potentially, aid in diagnosis and risk assessment.  This protocol aims to describe a method of quantifying and analyzing retinal vasculature and neuronal structure, which are potentially associated with dementia. This protocol also provides examples of retinal changes in subjects with dementia, and discusses technical issues and current limitations of retinal imaging.

Assessing Microvascular Function in Humans from a Chronic Disease Perspective

Microvascular dysfunction (MVD) is considered a crucial pathway in the development and progression of cardiometabolic and renal disease and is associated with increased cardiovascular mortality. MVD often coexists with or even precedes macrovascular disease, possibly due to shared mechanisms of vascular damage, such as inflammatory processes and oxidative stress. One of the first events in MVD is endothelial dysfunction. With the use of different physiologic or pharmacologic stimuli, endothelium-dependent (micro)vascular reactivity can be studied. This reactivity depends on the balance between various mediators, including nitric oxide, endothelin, and prostanoids, among others. The measurement of microvascular (endothelial) function is important to understand the pathophysiologic mechanisms that contribute to MVD and the role of MVD in the development and progression of cardiometabolic/renal disease. Here, we review a selection of direct, noninvasive techniques for measuring human microcirculation, with a focus on methods, interpretation, and limitations from the perspective of chronic cardiometabolic and renal disease.

Endothelial dysfunction in human essential hypertension

Although the endothelium has a number of important functions, the term endothelial dysfunction is commonly used to describe impairment in its vasodilatory capacity. It is increasingly recognized that this is related to hypertension, although whether it predates essential hypertension or is a consequence of it is still unknown. In this review, we explore the mechanisms of endothelial dysfunction in essential hypertension, its prognostic significance and methods of pharmacological reversal.

Shiftwork and the Retinal Vasculature Diameters Among Police Officers

OBJECTIVE

To investigate associations of central retinal arteriolar equivalent (CRAE), a measure of retinal arteriolar width, and central retinal venular equivalents (CRVE), a measure of retinal venular width, with shiftwork in 199 police officers (72.9% men).

METHODS

Shiftwork (day, afternoon, night) was assessed using electronic payroll records. Four digital retinal images per officer were taken. Mean diameters of the retinal vasculature were compared across shifts using analysis of variance (ANOVA)/analysis of covariance (ANCOVA).

RESULTS

Among all officers (mean age = 46.6 ± 6.8 years), shiftwork was not significantly associated with CRAE or CRVE. However, among current and former smokers, night-shift officers had a wider mean (±standard error [SE]) CRVE (230.0 ± 4.5 μm) compared with day shift officers (215.1 ± 3.5 μm); adjusted P = 0.014.

CONCLUSIONS

Night shift schedule in current and former smokers is associated with wider retinal venules. Reasons for this association are not known. Longitudinal studies are warranted.

Association between diabetic retinopathy and subclinical atherosclerosis in China: Results from a community-based study

PURPOSE

To evaluate the association of diabetic retinopathy with subclinical atherosclerosis in middle-aged and elderly Chinese with type 2 diabetes.

METHODS

A cross-sectional community-based study was performed among 1607 patients aged 40 years or older in Shanghai. Non-mydriatic digital fundus photography examination was used in diabetic retinopathy detection. Presence of elevated carotid intima-media thickness or carotid plaque was defined as subclinical atherosclerosis.

RESULTS

The prevalence of diabetic retinopathy was 15.1% in total patients. Patients with diabetic retinopathy were more likely to have elevated carotid intima-media thickness, carotid plaque and subclinical atherosclerosis than those without diabetic retinopathy (37.9% vs 30.7%, 57.6% vs 49.6% and 64.6% vs 57.1%, respectively). The presence of diabetic retinopathy was significantly associated with increased odds of subclinical atherosclerosis (odds ratio = 1.93, 95% confidence interval = 1.03-3.60) after full adjustments.

CONCLUSION

The presence of diabetic retinopathy was significantly associated with subclinical atherosclerosis in middle-aged and elderly patients with type 2 diabetics in China.

Relationship between Initial Lens Transparency and Ocular Circulation in Adolescents with Type-1 Diabetes Mellitus, Unstable Glycaemia and Lipid Parameters

BACKGROUND

The aim of this study was to determine the relationships between lens opacity, vascular and lipid factors and retrobulbar blood flow parameters in type-1 diabetic (DM) adolescents.

MATERIAL/METHODS

Glycated haemoglobin (HbA1c), total cholesterol (TCH), high- and low-density cholesterol, triglycerides (TG) and apolipoprotein B (ApoB) were determined in 28 patients with (DM-1) and without (DM-0) lens opacity and 18 controls. In the ophthalmic, central retinal (CRA) and temporal posterior ciliary (TPCA) arteries, the systolic (PSV), end-diastolic and mean blood flow velocities as well as pulsatility and resistance (RI) indices were measured.

RESULTS

Ten (35.71%) diabetic patients exhibited lens opacification. Higher TG and TCH levels in the DM-1 group and HbA1c level in the DM-0 and DM-1 groups were observed (P≤0.05). Diabetic patients had lower PSV and higher RI within CRA and TPCA (P≤0.05). Significant correlations between biochemical and blood flow parameters were found.

CONCLUSIONS

Glycaemic and lipid factors may play a vasoconstrictive role in retrobulbar endotheliopathy.

Validation of the automatic image analyser to assess retinal vessel calibre (ALTAIR): a prospective study protocol

INTRODUCTION

The fundus examination is a non-invasive evaluation of the microcirculation of the retina. The aim of the present study is to develop and validate (reliability and validity) the ALTAIR software platform (Automatic image analyser to assess retinal vessel calibre) in order to analyse its utility in different clinical environments.

METHODS AND ANALYSIS

A cross-sectional study in the first phase and a prospective observational study in the second with 4 years of follow-up. The study will be performed in a primary care centre and will include 386 participants. The main measurements will include carotid intima-media thickness, pulse wave velocity by Sphygmocor, cardio-ankle vascular index through the VASERA VS-1500, cardiac evaluation by a digital ECG and renal injury by microalbuminuria and glomerular filtration. The retinal vascular evaluation will be performed using a TOPCON TRCNW200 non-mydriatic retinal camera to obtain digital images of the retina, and the developed software (ALTAIR) will be used to automatically calculate the calibre of the retinal vessels, the vascularised area and the branching pattern. For software validation, the intraobserver and interobserver reliability, the concurrent validity of the vascular structure and function, as well as the association between the estimated retinal parameters and the evolution or onset of new lesions in the target organs or cardiovascular diseases will be examined.

ETHICS AND DISSEMINATION

The study has been approved by the clinical research ethics committee of the healthcare area of Salamanca. All study participants will sign an informed consent to agree to participate in the study in compliance with the Declaration of Helsinki and the WHO standards for observational studies. Validation of this tool will provide greater reliability to the analysis of retinal vessels by decreasing the intervention of the observer and will result in increased validity through the use of additional information, especially in the areas of vascularisation and vessel branching patterns.

TRIAL REGISTRATION NUMBER

Clinical Trials.gov Identifier: NCT02087605.

A histological investigation into the correlation of central retinal artery atherosclerosis with the systemic circulation

Current research suggests that retinal arterial changes such as arteriovenous nicking and arterial narrowing are pathologically distinct from atherosclerosis. Other studies have found a positive correlation between retinal changes and systemic atherosclerosis. However, limited recent histopathologic evidence assessing atherosclerosis in the central retinal artery exists. We investigated atherosclerosis in the central retinal artery and how it correlates to atherosclerosis in the carotid and coronary arteries. Twenty-two cadavers (12 males, 10 females) were dissected, obtaining one orbit, one carotid artery, and one coronary artery from each. The specimens were sectioned and stained for histologic analysis by light microscopy using hematoxylin and eosin, Verhoeff's elastic, and Gomori's trichrome stains. The degree of atherosclerosis was graded from absent, or I (least severe) to VIII (most severe) based on the current American Heart Association guidelines. Atherosclerotic changes were present in the central retinal, coronary, and carotid arteries. A positive correlation was found between the central retinal artery and the carotid artery (r = 0.23, P = 0.15), the central retinal artery and the coronary artery (r = 0.31, P = 0.08), and the carotid artery and the coronary artery (r = 0.45, P = 0.02). The presence of low-grade atherosclerosis in the central retinal artery is prevalent in a population of advanced vascular disease. However, central retinal artery atherosclerotic lesion severity is poorly correlated with disease severity in the carotid and coronary arteries.

Retinal microvascular abnormalities are associated with early carotid atherosclerotic lesions in hospitalized Chinese patients with type 2 diabetes mellitus

OBJECTIVE

Controversies concerning the association of retinal microvascular abnormalities (RMAs) with atherosclerosis in patients with diabetes exist. The objective of this study was to investigate the association between RMAs and carotid atherosclerotic lesions in Chinese inpatients with type 2 diabetes.

METHODS

This cross-sectional study involved 2870 type 2 diabetic patients including 1602 men aged 15-90 years and 1268 women aged 17-88 years. Both retinal arteriosclerosis (RA) and diabetic retinopathy (DR) were determined by digital fundus photography using a standardized protocol. RMAs are defined as the presence of either RA or DR. Carotid atherosclerotic lesions including carotid intima-media thickness (CIMT), carotid atherosclerotic plaque and stenosis were assessed and compared between patients with and without RMAs based on Doppler ultrasound. The association of RMAs with carotid atherosclerotic lesions was analyzed by linear and binary logistic regression analyses.

RESULTS

The CIMT values in both male and female diabetics with RMAs were significantly greater than in those without RMAs after controlling for age (0.88±0.21 vs. 0.77±0.20 mm for men, p=0.002; and 0.84±0.19 vs. 0.76±0.21 mm for women, p=0.002). The prevalence of carotid plaque was also markedly higher in patients with RMAs than in those without RMAs after adjusting for age (54.3% vs. 23.9% for men, p<0.001; 48.4% vs. 32.0% for women, p=0.046). However, no significant difference was observed in the prevalence of carotid stenosis in either men or women with or without RMAs. After controlling for multiple confounding factors, RMAs were independently associated with increased CIMT in both men (β: 0.067, 95% CI: 0.026-0.269, p=0.018) and women (β: 0.087, 95% CI: 0.058-0.334, p=0.005) with type 2 diabetes, and they were also closely associated with the presence of carotid plaque (OR: 2.17, 95% CI: 1.54-3.05, p<0.001 for men; OR: 1.38, 95% CI: 0.91-2.08, p=0.129 for women) in men with type 2 diabetes.

CONCLUSIONS

RMAs were closely associated with early carotid atherosclerotic lesions in hospitalized Chinese patients with type 2 diabetes. Our results suggested that changes in retinal microvasculature may play a role in the pathogenesis of atherosclerosis and may be used as an indicator of early atherosclerosis in patients with type 2 diabetes.

Relationship between target organ damage and blood pressure, retinal vessel calibre, oxidative stress and polymorphisms in VAV-2 and VAV-3 genes in patients with hypertension: a case-control study protocol (LOD-Hipertension)

INTRODUCTION

Target organ damage (TOD) is associated with increased cardiovascular risk. The study objectives were to analyse the relationship of TOD to blood pressure, size of retinal arteries and veins, oxidative stress and different polymorphisms in the VAV-2 and VAV-3 genes in participants with hypertension.

METHODS AND ANALYSIS

A case-control study to analyse the relationship between clinical, biochemical and genetic parameters and presence of cardiac, vascular and renal TOD in 486 patients with hypertension. Participants with TOD will be considered as cases, and those without TOD will be enrolled as controls. This will be a collaborative study conducted by the groups of Primary Care, Cardiovascular and Metabolic and Degenerative Diseases of the Instituto de Investigación Biomédica of Salamanca (IBSAL). Assessment of cardiac, renal and vascular TOD. Measurement of peripheral and central blood pressure, size of eye fundus arteries and veins, and oxidative stress, and polymorphisms in the VAV-2 and VAV-3 genes.

ETHICS AND DISSEMINATION

The study will be conducted after approval is obtained from the Ethics Committee of Hospital Clínico Universitario of Salamanca. All study participants will sign an informed consent to agree to participate in the study, and another consent to agree on the genetic study, in compliance with the Declaration of Helsinki and the WHO standards for observational studies. The results of this study will allow for an understanding of the relationship of the different TODs with blood pressure, retinal artery and vein diameters, oxidative stress and polymorphisms in VAV-2 and VAV-3 genes.

TRIAL REGISTRATION NUMBER

Clinical Trials. gov Identifier: NCT02022618.

Diabetic retinopathy and endothelial dysfunction in patients with type 2 diabetes mellitus

BACKGROUND

We investigated the relationship between endothelial dysfunction and diabetic retinopathy (DR) in patients with type 2 diabetes.

METHODS

We used a cross-sectional design to examine 167 patients with type 2 diabetes mellitus. All patients underwent biochemical and ophthalmological examination. We assessed endothelial dysfunction by a flow-mediated vasodilation method of the brachial artery. Changes in vasodilation (flow-mediated vasodilatation, %FMD) were expressed as percent change over baseline values.

RESULTS

The mean±standard deviation of patient age was 54.1±8.6 years. The %FMD was significantly lower in patients with DR than without DR. The prevalence of retinopathy decreased across increasing tertiles of %FMD. After adjusting for patients' age, sex, diabetes duration, use of insulin, use of antihypertensive, antiplatelet, and lipid lowering medications, systolic blood pressure, fasting plasma glucose, 2-hour plasma glucose, glycated hemoglobin, and urinary albumin excretion, participants with a reduced %FMD were more likely to have DR (odds ratio, 11.819; 95% confidence interval, 2.201 to 63.461; P=0.004, comparing the lowest and highest tertiles of %FMD).

CONCLUSION

Endothelial dysfunction was associated with DR, which was most apparent when the endothelial dysfunction was severe. Our study provides insights into the possible mechanism of the influence of endothelial dysfunction on the development of DR.

Clinical determinants of carotid intima-media thickness in patients with diabetes mellitus type 2

BACKGROUND AND PURPOSE

Early atherosclerotic changes in carotid arteries can be detected using ultrasound examination. The aim of this study was to assess correlations between intima-media thickness (IMT) and gender, age and clinical features of diabetes mellitus (DM).

MATERIAL AND METHODS

The study group consisted of 73 patients with type 2 DM (mean age: 63.6 ± 7.5 years), and 74 controls without DM (mean age 62.2 ± 7.5 years). Analysed clinical features of diabetes included disease duration, anti-diabetic treatment, glycaemic control (HbA1c level), presence of metabolic syndrome, and complications of macro- and microangiopathy. IMT was measured using ultrasonography in the carotid arteries (common - CCA, bifurcation, internal - ICA) bilaterally.

RESULTS

Mean and maximum IMT in the CCA was greater in diabetic patients than in controls. Age and male sex, but not vascular risk factors, were independent predictors of increased IMT in all segments. Macroangiopathy correlated with IMT within both CCA in univariate analysis. After adjusting for age and gender, this relationship remained significant in the right CCA in middle-aged patients (59-67 years; p = 0.01 for mean IMT, p = 0.02 for maximum IMT). In patients without metabolic syndrome, IMT in the right CCA bifurcation correlated with HbA1c level (p = 0.05). Patients treated simultaneously with insulin and oral antidiabetic drugs had smaller IMT in the right ICA than those treated with insulin only (0.471 ± 0.105 vs. 0.678 ± 0.209 mm; p = 0.04).

CONCLUSIONS

In diabetic patients, ultrasound IMT measurement can be used to assess the cardiovascular risk and to determine indications for intensified anti-diabetic treatment. IMT is a sensitive marker of early carotid atherosclerosis, particularly on the right side.

The levels of the circulating cellular adhesion molecules ICAM-1, VCAM-1 and endothelin-1 and the flow-mediated vasodilatation values in patients with type 1 diabetes mellitus with early-stage diabetic retinopathy

OBJECTIVE

Endothelial dysfunction plays an important role in the development of diabetic retinopathy. The aim of this study was to evaluate endothelial dysfunction using different approaches in patients with type 1 diabete mellitus with early stages of diabetic retinopathy. For this purpose, we investigated the serum levels of cellular adhesion molecules, including intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1) and endothelin-1 (ET-1), which have emerged as specific markers of endothelial dysfunction, and measured the flow-mediated dilatation (FMD), a noninvasive technique used to evaluate endothelial dysfunction.

METHODS

The study group included 59 patients with type 1 diabetes mellitus (DM) and 30 age-matched healthy control subjects. The diabetic patients were divided into two groups according to the ophthalmoscopic findings: Group 1, composed of type 1 diabetic patients having no signs of diabetic retinopathy (DRP), and Group 2, composed of type 1 diabetic patients having findings of the early stages of nonproliferative diabetic retinopathy (NPDR).

RESULTS

The serum levels of ET-1 (fmol/mL), ICAM-1 (ng/mL) and VCAM-1 (ng/mL) were 8.52±0.699 vs. 478.39±46.22 vs. 728.64±35.081 in the patients without retinopathy, 8.91±1.354 vs. 451.79±48.262 vs. 863.59±62.37 in the diabetic patients with NPDR and 10.73±1.04 vs. 608.15±74.92 vs. 872.95±57.63 in the control group. There were no significant differences in the serum levels of the three molecules between the groups. The FMD values were 6.51±0.46% in the diabetic patients without retinopathy, 6.66±0.29% in the diabetic patients with NPDR and 6.68±0.51% in the control group. No significant differences were found between the groups.

CONCLUSION

The early stages of diabetic retinopathy cannot be considered in the evaluation of systemic markers of endothelial dysfunction.

A new tool to assess retinal vessel caliber. Reliability and validity of measures and their relationship with cardiovascular risk

OBJECTIVE

To analyze the reliability and validity of a semiautomated tool for assessing retinal vessel caliber and to describe the relationship of measures taken to cardiovascular risk and target organ damage.

METHODS

A total of 210 patients aged 34-75 years were selected with retinography. Retinal photographs were digitized, and superior and inferior temporal vessels were measured in an area 0.5-1 disk diameter from the optic disc with semiautomated software [arteriole/venule index (AVIx) calculator]. AVIx was also estimated. Vascular damage was assessed using carotid intima-media thickness and pulse wave velocity, cardiac damage using Cornell voltage-duration product, renal damage using the glomerular filtration rate and microalbuminuria, and cardiovascular risk with the Framingham score.

RESULTS

Interobserver intraclass correlation coefficient (ICC) ranged from 0.96 [95% confidence interval (CI) 0.94-0.97] to 0.99 (95% CI 0.98-0.99), and intraobserver ICC ranged from 0.97 (95% CI 0.94-0.98) to 0.99 (95% CI 0.99-0.99). In the Bland-Altman plot, the limit of interobserver agreement was -0.009 (0.066 to -0.086) in right AVIx and -0.001 (0.083 to -0.085) in left AVIx, whereas the limit of intraobserver agreement for overall AVIx was -0.005 (-0.057 to -0.047). Cardiovascular risk and albumin-creatinine ratio were higher in the first tertile of AVIx as compared with the other two (P < 0.05). In multiple regression, AVIx and venule caliber, but not artery caliber, behaved as predictors of cardiovascular risk and microalbuminuria.

CONCLUSION

This tool showed a high intraobserver and interobserver reliability, and results of the validity analysis agree with those from large studies in estimation of cardiovascular risk and evaluation of target organ damage.

Association between diabetic retinopathy and flow-mediated vasodilation in type 2 DM

OBJECTIVE

Retinal endothelial dysfunction is a key in the etiogenesis of diabetic retinopathy (DR), in patients with type 2 diabetes mellitus (DM). Brachial artery flow-mediated vasodilation (FMD) is a marker of endothelial function associated with production of endogenous nitric oxide. Using FMD, we investigated the relationship between macrovascular function and DR.

METHODS

We studied 74 patients with type 2 DM, including non-DR (NDR) (n = 30); mild nonproliferative DR (NPDR) (n = 16); moderate NPDR (n = 10); severe NPDR (n = 10); and proliferative DR (PDR) (n = 8); and 21 age-matched controls. We measured FMD in each group. Retinal blood flow and pulsatility ratios were measured using laser Doppler velocimetry.

RESULTS

FMD decreased significantly in patients with DM compared with healthy control subjects. No significant differences were found in FMD among the NDR, mild NPDR, and moderate NPDR groups. FMD decreased significantly in the severe NPDR and PDR groups compared with the NDR group. FMD was significantly and negatively correlated with duration of DM and pulsatility ratio.

CONCLUSION

Systemic endothelial dysfunction appears to be associated with DR and vascular abnormalities in patients with type 2 DM.

Diabetic retinopathy is related to both endothelium-dependent and -independent responses of skin microvascular flow

OBJECTIVE

Endothelial dysfunction has been hypothesized as a possible pathogenic factor in the development of diabetic retinopathy (DR). We examined the relationship of DR to endothelium-dependent and endothelium-independent responses in skin microvascular flow.

RESEARCH DESIGN AND METHODS

Participants consisted of 224 individuals with diabetes: 85 with type 1 diabetes and 139 with type 2 diabetes. Sodium nitroprusside (SNP) and acetylcholine (ACh) were delivered across the skin by iontophoresis. Laser Doppler flowmetry was used to assess the skin microcirculation response to SNP (endothelium-independent response) and ACh (endothelium-dependent response). The presence and severity of DR were graded from retinal photographs using a standard protocol.

RESULTS

Of 224 participants, 64.3% had DR. After multivariable adjustment, participants with reduced responses to SNP or ACh were more likely to have DR, with an odds ratio (OR) of 2.33 (95% CI 1.09-5.01) for SNP and 2.20 (1.05-4.61) for ACh, comparing participants with responses below and above the median values. Participants with reduced responses (below the median) to both SNP and ACh were nearly four times more likely to have DR (OR 3.86 [1.45-10.3]) than those with SNP and ACh both above the median values.

CONCLUSIONS

The presence of DR was associated with a reduction in skin microcirculation responses to iontophoresis of both SNP and ACh, suggesting that vascular processes associated with both endothelial dysfunction and endothelial function-independent mechanisms may be pathogenically related to DR.

Reduced retinal blood flow velocity in diabetic retinopathy

PURPOSE

The purpose of this study was to compare the retinal blood flow velocities of patients with diabetes and healthy control subjects. We used a novel device offering a noninvasive diagnostic of retinal function.

METHODS

Flow velocities in retinal arterioles and venules were quantitatively analyzed by retinal function imager scanning in 58 eyes of 42 patients with nonproliferative diabetic retinopathy and 51 eyes of 32 normal subjects. Group differences were assessed by the mixed-model effect.

RESULTS

Average velocity in arterial compartments (in mm/s) was 3.74 +/- 1.09 for the diabetic group and 4.19 +/- 0.99 for the control subjects. The average velocity of all segments, taking associated heart rate and individual segment widths into account, was 17% slower in the diabetic group (P < 0.0001). In both groups, average venous compartment velocity was lower than the arterial velocity (2.61 +/- 0.65 for the diabetic group; 3.03 +/- 0.59 for the control subjects). Individual vein velocities, taking heart rate and segment widths into account, was 17% slower, on average, in the diabetic group (P < 0.0001).

CONCLUSION

Our measurement showed significantly decreased flow velocities in the retinal arterioles and venules of patients with diabetes compared with healthy control subjects, supporting the view of abnormal vessel function in eyes with nonproliferative diabetic retinopathy.

Retinal vascular caliber and brachial flow-mediated dilation: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND PURPOSE

Retinal vascular caliber changes have been shown to predict stroke, but the underlying mechanism of this association is unknown. We examined the relationship between retinal vascular caliber with brachial flow-mediated dilation (FMD), a measure of systemic endothelial function.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based study of persons 45 to 84 years of age residing in 6 US communities free of clinical cardiovascular disease at baseline. Brachial FMD data were collected at baseline (July 2000 to June 2002), and retinal vascular caliber was measured from digital retinal photographs at the second examination, immediately after the first (August 2002 to January 2004). Data were available for 2851 participants for analysis.

RESULTS

The mean brachial FMD was 4.39+/-2.79%. After adjusting for age and gender, brachial FMD was reduced in persons with wider retinal venular caliber (changes in FMD -0.25, 95% CI, -0.36, - 0.13; P<0.001, per SD increase in venular caliber). This relationship persists after adjusting for systolic blood pressure, serum total cholesterol, use of lipid-lowering and antihypertensive medication, body mass index, current smoking status, and hemoglobinA(1C) (-0.18; 95% CI -0.30, - 0.06; P=0.004, per SD increase in venular caliber). Brachial FMD was not associated with retinal arteriolar caliber.

CONCLUSIONS

Persons with wider retinal venules have reduced brachial FMD, independent of other vascular risk factors. This suggests that retinal venular caliber, previously shown to predict stroke, may be a marker of underlying systemic endothelial dysfunction.

The relationship between retinal microvascular abnormalities and coronary heart disease: a review

Heart disease remains the leading cause of death in the United States despite decades of advancement in its diagnosis and treatment. Because of the limitations of traditional risk stratification for heart disease, evaluation of the retinal vasculature has been proposed as an easily and safely measured adjunct to commonly used screening methods. This article provides a comprehensive review of the literature concerning the relationships between retinal microvascular abnormalities and coronary heart disease. We outline details of the most recent large epidemiologic studies and discuss their potential implications for clinical practice. Finally, we propose a change to the current guidelines regarding the screening of "low-risk" women, a group that is often failed by traditional evaluation algorithms.

Cerebrovascular disease in diabetes mellitus: the role of carotid intima-media thickness

BACKGROUND AND PURPOSE

Cerebrovascular disease in diabetes appears to be less considered than coronary and peripheral disease, the reason being the intrinsic difficulty in finding available diagnostic tools for its early identification. Among these, carotid artery intima-media thickness (cIMT) represents the simplest measurable parameter for pre-atherosclerotic lesions in extra-cranic arteries.

METHODS

The role of cIMT as a surrogate marker of cerebral atherosclerosis and predictor of stroke, its relationship to microangiopathy and chronic inflammation, along with its role as an outcome parameter in anti-hyperglycemic therapeutical intervention trials in type 2 and 1 diabetes mellitus are discussed in this paper.

RESULTS AND CONCLUSIONS

Carotid IMT is increased in diabetes. It is an independent predictor of stroke, in particular of the ischemic subtype, and of stroke recurrence in diabetic, as well as in non-diabetic populations. A possible role of cIMT as a predictor of microangiopathy has also been suggested, but it needs further investigation. A weak association with chronic inflammation has been demonstrated in diabetic patients. Carotid IMT has been successfully employed as an outcome parameter for several anti-hyperglycemic therapeutic trials. However data on cIMT as a predictor of cerebrovascular disease are scarce in diabetic patients, particularly in type 1 diabetes, and more studies are needed to define the risk of cerebrovascular disease in diabetic patients.

Retinal vascular caliber and extracranial carotid disease in patients with acute ischemic stroke: the Multi-Centre Retinal Stroke (MCRS) study

BACKGROUND AND PURPOSE

Previous studies show that both retinal vascular caliber and carotid disease predict incident stroke in the general population, but the exact relationship between these 2 microvascular and macrovascular structural risk factors is unclear. We studied the relationship between retinal vascular caliber and carotid disease in patients presenting with acute ischemic stroke.

METHODS

We conducted a cross-sectional study of patients with acute ischemic stroke recruited from 3 centers (Melbourne, Sydney, Singapore). The caliber of retinal arterioles and venules was measured from digital retinal photographs. Severe extracranial carotid disease was defined as stenosis >or=75% or occlusion determined by carotid Doppler using North American Symptomatic Carotid Endarterectomy Trial-based criteria.

RESULTS

Among the 1029 patients with acute stroke studied, 7% of the population had severe extracranial carotid disease. Retinal venular caliber was associated with ipsilateral severe carotid disease (P<0.001 in multivariate models). Patients with wider retinal venular caliber were more likely to have severe ipsilateral carotid disease (multivariable-adjusted OR, 3.81; 95% CI, 1.80 to 8.07, comparing the largest and smallest venular caliber quartiles). The retinal venular caliber-carotid disease association remained significant in patients with large artery stroke.

CONCLUSIONS

In patients with acute stroke, retinal venular widening was strongly associated with ipsilateral severe extracranial carotid disease. Our findings suggest concomitant retinal and cerebral microvascular disease may be present in patients with carotid stenosis or occlusion disease. The pathogenesis of stroke due to carotid disease may thus be partially mediated by microvascular disease.

Functional imaging using the retinal function imager: direct imaging of blood velocity, achieving fluorescein angiography-like images without any contrast agent, qualitative oximetry, and functional metabolic signals

The Retinal Function Imager (RFI; Optical Imaging, Rehovot, Israel) is a unique, noninvasive multiparameter functional imaging instrument that directly measures hemodynamic parameters such as retinal blood-flow velocity, oximetric state, and metabolic responses to photic activation. In addition, it allows capillary perfusion mapping without any contrast agent. These parameters of retinal function are degraded by retinal abnormalities. This review delineates the development of these parameters and demonstrates their clinical applicability for noninvasive detection of retinal function in several modalities. The results suggest multiple clinical applications for early diagnosis of retinal diseases and possible critical guidance of their treatment.

Retinopathy in type 2 diabetes mellitus is associated with increased intima-media thickness and endothelial dysfunction

BACKGROUND

Microangioathy and macroangiopathy in type 2 diabetes mellitus (T2DM) frequently coexist. Both types of vascular complications share traditional risk factors. It is not clear whether the presence of microangiopathy, such as diabetic retinopathy (DR), constitutes a predictor of atherosclerosis in T2DM. Here we described the search for the association between DR and intima-media thickness (IMT) in T2DM. We also compared endothelial function in subjects with and without DR.

MATERIAL AND METHODS

We examined 182 consecutive patients with T2DM for at least 5 years (mean age at examination 56.3 +/- 6.52 years). We assessed (i) IMT of carotid artery by ultrasound and (ii) endothelial function by flow-mediated dilatation (FMD) method as well as by measurement of concentrations of von Willebrand factor (vWF) and s-ICAM-1. All patients underwent ophthalmological examination. Statistical analysis included Student's, Mann-Whitney, chi-square, Fisher tests and multiple regression.

RESULTS

DR was found in 71 (39.0%) subjects. IMT was higher in patients with DR than those without DR (0.87 mm vs. 0.79 mm, respectively, P = 0.0001). FMD was lower in the complication group than in subjects without DR (8.38% vs. 10.45%, respectively, P = 0.0023). Concentrations of s-ICAM-1 and vWF were not different between the groups. In multiple regression analysis, DR was among the predictors of increased IMT (P = 0.016) and decreased FMD (P = 0.002). We did not find a significant association of DR with vWF and s-ICAM-1 (P = 0.09 and P = 0.11, respectively).

CONCLUSIONS

DR is associated with increased IMT and endothelial dysfunction in T2DM. Impaired endothelial function may be a common denominator of pathogenesis of microvascular complications and atherosclerosis in T2DM.

Relative importance of systemic determinants of retinal arteriolar and venular caliber: the atherosclerosis risk in communities study

OBJECTIVE

To examine the relative contributions of systemic cardiovascular factors to retinal arteriolar and venular caliber in men and women and in whites and African Americans.

METHODS

In the Atherosclerosis Risk in Communities study, retinal arteriolar caliber (central retinal arteriolar equivalent), and venular caliber (central retinal venular equivalent) were measured from digitized retinal photographs of 8794 participants.

RESULTS

The main systemic determinants of narrower central retinal arteriolar equivalent were, in order of relative decreasing contribution, higher current mean arterial blood pressure, lower serum albumin level, current alcohol consumption, and higher body mass index (calculated as weight in kilograms divided by height in meters squared). The main systemic determinants of wider central retinal venular equivalent were current cigarette smoking and higher current mean arterial blood pressure, followed by higher white blood cell count, body mass index, and plasma low-density lipoprotein cholesterol levels. These associations were generally similar in whites and African Americans and in men and women.

CONCLUSIONS

The major systemic determinant of narrower retinal arteriolar caliber is higher blood pressure, while those of wider retinal venular caliber are cigarette smoking, higher blood pressure, systemic inflammation, and obesity. These data offer further insights into the systemic processes influencing arteriolar and venular characteristics and may help explain the observed associations of retinal vascular caliber and the risk of clinical cardiovascular disease.

Retinal vascular signs in diabetes and hypertension--review

The retinal vasculature is a unique site where the microcirculation can be noninvasively imaged in vivo. This presents an opportunity to study otherwise inaccessible structural features of the microcirculation. Recently, a number of population-based studies have developed quantitative methods of measuring these retinal signs, and investigated how these signs relate to metabolic disorders such as diabetes, hypertension, obesity, and metabolic syndrome. These studies have reported fairly consistent associations of retinopathy lesions, arteriolar narrowing and venular dilation with these metabolic disorders, suggesting a microvascular component in either the pathogenesis or manifestation of these disorders. Further, several of these signs have been associated with future risk of cardiovascular outcomes, such as coronary heart disease and stroke, independently of traditional risk factors. This review will examine in detail the evidence linking retinal vascular signs with metabolic disorders and discuss their implications for research and clinical practice.