Nicholas W. Witt

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Abnormalities of the retinal microcirculation are found in hypertension and diabetes and predict cardiovascular mortality. This study examined the relationship between abnormalities of the retinal microvasculature and death from ischemic heart disease (IHD) and stroke. A population-based, nested case-control study was undertaken within the Beaver Dam Eye(More)
BACKGROUND The impact of early life factors on the microvasculature is relatively unknown. OBJECTIVES We hypothesized that small birth size may be associated with structural variations in the retinal vasculature in children. METHODS The Avon Longitudinal Study of Parents and Children followed a cohort of children born in 1991-1992 from birth. The(More)
PURPOSE Diabetes has adverse effects on the retinal microvasculature. The purpose of this study was to compare the effects of inhalation of hypoxic, hyperoxic and normoxic-hypercapnic gas mixtures on retinal vessel diameter in people with and without diabetes. METHODS Sixty-one participants (aged 24-50 years) 29 with (male : female ratio 2.6 : 1) and 32(More)
OBJECTIVE To study the association of the inflammatory markers serum amyloid A (SAA) and C-reactive protein (CRP) with retinal microvascular parameters in hypertensive individuals with and without type 2 diabetes. RESEARCH DESIGN AND METHODS This cross-sectional analysis was a substudy in 711 patients (159 with and 552 without diabetes) of the(More)
BACKGROUND Recent studies have shown that changes in the retinal microvasculature predict cardiovascular disease (CVD); however, little is known regarding influences on the retinal microvasculature in healthy people without overt cardiovascular or metabolic disease. METHODS We used a semiautomated computerized technique to analyze digitized retinal(More)
Conventionally, the relationship between parent and daughter vessels at vascular bifurcations has been expressed by the junction exponent (x), and deviations of this parameter from the optimal conditions predicted by Murray's law (x = 3) have been shown to be associated with vascular disease. However, the junction exponent is normally calculated iteratively(More)
OBJECTIVE We hypothesized that preterm birth and being born SGA would be associated with changes in retinal microvascular architecture and that these changes would be more marked among those born preterm. We further hypothesized that these microvascular changes would correlate with early markers of CVD in mid-adulthood. METHODS The Cardiovascular Risk in(More)
BACKGROUND AND PURPOSE Abnormalities of the retinal circulation may be associated with cerebrovascular disease. We investigated associations between retinal microvascular abnormalities and (1) strokes and subclinical cerebral infarcts and (2) cerebral white matter lesions in a UK-based triethnic population-based cohort. METHODS A total of 1185(More)
Changes in the retinal microcirculation are associated with hypertension and predict cardiovascular mortality. There are few data describing the impact of antihypertensive therapy on retinal vascular changes. This substudy of the Anglo-Scandinavian Cardiac Outcomes Trial compared the effects of an amlodipine-based regimen (373 patients) with an(More)
1 Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital and University of Bern, Bern, Switzerland 2 International Center for Circulatory Health, NHLI, Imperial College, London, UK 3 Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland 4 International Public Health Unit, School of Public Health and(More)