Morphometric Age-Related Evaluation of Small Retinal Vessels by Scanning Laser Doppler Flowmetry

Michelson, Georg; Wärntges, Simone; Baleanu, D.; Welzenbach, Jürgen; Ohno-Jinno, Akiko; Pogorelov, P.; Harazny, Joanna

doi:10.1097/01.iae.0000243032.33738.f7

Cited by 28 publications

(20 citation statements)

References 27 publications

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“…Techniques such as scanning laser doppler flowmetry and scanning laser ophthalmoscopy 40,41 permit in vivo measurement of microcirculatory blood flow that is inaccessible in any other microcirculation. When coupled with imaging of the retinal vessels, estimates of retinal vessel wall thickness may be obtained, 40,41 providing a unique means of determining actual arteriolar and venular wall thickness, which is clearly of value in assessing the health of the microcirculation. Some studies have shown that these measures may track the microcirculatory response to therapy for hypertension and may identify increased cerebrovascular risk.…”

Section: Functional Measures Of the Retinal Microvasculature Complemementioning

confidence: 99%

Retinal Vascular Imaging

Liew

Wang

Mitchell

et al. 2008

Circ: Cardiovascular Imaging

281

101

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Abstract-T he microcirculation represents the bulk of the circulatory system; yet, its role in the cardiovascular disease is less clear than the role of the macrocirculation (ie, large vessel disease). This is partly because current methods to investigate the microvasculature are invasive and can be performed only in highly specialized settings, which limits their utility as tools to understand the clinical consequences of microvascular disease.The retina is a unique site where the in vivo microvasculature can be directly visualized and monitored repeatedly over time. Recent advances in retinal photographic imaging techniques have facilitated the development of computerassisted methods to measure and quantify subtle variations and abnormalities in the retinal microvasculature. 1,2 These quantitative assessments have been applied to large populations, of both adults and children, and in community and clinic settings. Existing data now convincingly show links between a range of retinal microvascular signs and both clinical and subclinical cerebrovascular, cardiovascular, and metabolic outcomes. 3 Thus, retinal vascular imaging offers the potential to provide information that summarizes the cumulative microcirculatory effects of an individual's lifetime exposures to lifestyle and environmental factors, and the body's responses to these exposures, which may in turn be modified by genetic predisposition.Retinal vascular imaging is currently used in 2 broad areas of cardiovascular research. First, retinal imaging is a novel, noninvasive research tool to probe the role and pathophysiology of the microvasculature, typically defined as vessels between 100 and 300 m in size, in the development of clinical cardiovascular disease. 4 Second, retinal vascular imaging is explored in clinical settings as a risk stratification tool to aid clinicians in identifying patients with microvascular signs who are at high risk of future clinical cardiovascular and cerebrovascular events. A third possibility is under investigation: retinal vascular imaging has potential as a surrogate measure of the microvascular benefits of new therapeutic agents in early phase II or even phase III studies. 5 Although this prospect has been raised, several critical issues must be addressed before retinal vascular imaging can be considered a valid surrogate for assessing outcomes in cardiovascular clinical trials. The unique perspective offered by retinal vascular image analysis is used by an increasing number of researchers and research groups to address scientific questions that are difficult to answer through other means. Some key questions this new technique has been applied to are described later, as are major issues that remain to be addressed. Retinal Vascular Imaging TechnologiesSeveral semiautomated programs to measure retinal vascular caliber have been developed and described. The most widely used program was developed and validated in the Atherosclerosis Risk in Communities Study to examine the retinal vascular signs of arteriosclerosis in 11 1...

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Section: Functional Measures Of the Retinal Microvasculature Complemementioning

confidence: 99%

Retinal Vascular Imaging

Liew

Wang

Mitchell

et al. 2008

Circ: Cardiovascular Imaging

281

101

View full text Add to dashboard Cite

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“…OD was measured in reflection images and ID was measured in perfusion images. The algorithm on which the assessment of OD and ID is based was described previously in detail [17]. Analyses of diameters were performed offline with AFFPIA (SLDF version 3.7 by Welzenbach).…”

Section: Measurement Of Retinal Arteriolar Structurementioning

confidence: 99%

Wall-to-lumen ratio of retinal arterioles is related with urinary albumin excretion and altered vascular reactivity to infusion of the nitric oxide synthase inhibitor N-monomethyl-L-arginine

Ritt

Harazny

Ott

et al. 2009

Journal of Hypertension

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“…19 The mean retinal capillary blood flow was calculated in the area of interest and expressed as arbitrary units.…”

Section: Measurement Of Retinal Capillary Blood Flowmentioning

confidence: 99%

“…18 Thereby, vessel diameters are detected by AFFPIA in reflectivity images, as described previously. 19 The mean retinal capillary blood flow was calculated in the area of interest and expressed as arbitrary units.…”

Section: Measurement Of Retinal Capillary Blood Flowmentioning

confidence: 99%

Impaired Increase of Retinal Capillary Blood Flow to Flicker Light Exposure in Arterial Hypertension

et al. 2012

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Abstract-We hypothesized that the increase of retinal capillary blood flow (RCF) to flicker light exposure is impaired in subjects with arterial hypertension. In 146 nondiabetic untreated male subjects with (nϭ50) or without (nϭ96) arterial hypertension, RCF was measured before and after flicker light exposure noninvasively and in vivo using scanning laser Doppler flowmetry. In addition, in a subgroup of 28 subjects, the change of RCF to flicker light exposure was again assessed during parallel infusion of nitric oxide synthase inhibitor N-monomethyl-L-arginine (L-NMMA). The increase of RCF to flicker light exposure was lower in patients with untreated hypertension compared with normotensive subjects when expressed in absolute terms (7.69Ϯ54 versus 27.2Ϯ44 AU; P adjustedϭ0.013) or percent changes (2.95Ϯ14 versus 8.33Ϯ12%; P adjustedϭ0.023). Systolic (␤ϭϪ0.216; Pϭ0.023) but not diastolic blood pressure (␤ϭϪ0.117; Pϭ0.243) or mean arterial pressure (␤ϭϪ0.178; Pϭ0.073) was negatively related to the percent change of RCF to flicker light exposure, independently of other cardiovascular risk factors. In the subgroup of 28 subjects, the increase of RCF to flicker light exposure was similar at baseline and during parallel infusion of L-NMMA when expressed in absolute terms (20.0Ϯ51 versus 22.6Ϯ56 AU; Pϭ0.731) or percent changes (7.12Ϯ16 versus 8.29Ϯ18%; Pϭ0.607). The increase of RCF to flicker light exposure is impaired in arterial hypertension. In the subgroup of the total study cohort, nitric oxide was not a major determinant of the increase of RCF to flicker light exposure. (Hypertension. 2012;60:871-876.)Key Words: retina Ⅲ capillary blood flow Ⅲ vasodilatory properties Ⅲ nitric oxide Ⅲ arterial hypertension A rterial hypertension is a major determinant of morbidity and mortality due to cardiovascular complications. 1 Reduction in systolic and diastolic blood pressure levels was found to reduce and slow the occurrence of cardiovascular events in subjects with arterial hypertension 2 ; however, blood pressure levels per se might be unreliable indicators of cardiovascular risk in the individual subjects. In arterial hypertension, elevated blood pressure levels lead to structural and functional changes of blood vessels and organ damage, such as retinopathy, thickening of carotid arteries, large artery stiffening, left ventricular hypertrophy, and increased urinary albumin excretion, among others. These subclinical parameters represent intermediate end points that frequently precede major cardiovascular events and indicate the need for aggressive medical blood pressure control in context of individual global cardiovascular risk profile. 2Since the famous work by Keith, Wagener, and Barker,3 several studies have demonstrated the prognostic significance of retinal vascular alterations for predicting morbidity and mortality in subjects with arterial hypertension [4][5][6] ; however, owing to improvement in patient management, nowadays, grade 3 and grade 4 hypertensive retinopathy are seldom observed, and grade 1 and 2 hype...

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Morphometric Age-Related Evaluation of Small Retinal Vessels by Scanning Laser Doppler Flowmetry

Abstract: In a group of subjects aged 21 years to 70 years, we detected an increase of Delta(VD-FD)/2 in the retinal temporal superior artery and vein with age.

Cited by 28 publications

References 27 publications

Retinal Vascular Imaging

Retinal Vascular Imaging

Wall-to-lumen ratio of retinal arterioles is related with urinary albumin excretion and altered vascular reactivity to infusion of the nitric oxide synthase inhibitor N-monomethyl-L-arginine

Impaired Increase of Retinal Capillary Blood Flow to Flicker Light Exposure in Arterial Hypertension

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