RESUMEN
Screening for hypertensive organ damage is important in assessing cardiovascular risk in hypertensive individuals. In a 20-year follow-up of normotensive and hypertensive men, signs of end-organ damage were examined, focusing on hypertensive retinopathy. In all, 56 of the original 79 men were reexamined for hypertensive organ damage, including by digital fundus photography. The diameters of the central retinal artery equivalent (CRAE) and vein were estimated and the artery-to-vein diameter ratio calculated. Components of metabolic syndrome were assessed. Fifty percent of the normotensive men developed hypertension during follow-up. Significant differences appeared in CRAE between the different blood pressure groups (P=0.025) while no differences were observed for other markers of hypertensive organ damage. There were significant relationships between CRAE and blood pressure at baseline (r=-0.466, P=0.001) and at follow-up (r=-0.508, P<0.001). A linear decrease in CRAE was observed with increasing number of components of the metabolic syndrome (beta=-3.947, R(2)=0.105, P=0.023). Retinal vascular diameters were closely linked to blood pressures and risk factors of the metabolic syndrome. The diversity in the development of hypertensive organ damage, with changes in retinal microvasculature preceding other signs of damage, should encourage more liberal use of fundus photography in assessing cardiovascular risk in hypertensive individuals.
Asunto(s)
Presión Sanguínea , Hipertensión/complicaciones , Hipertensión/fisiopatología , Enfermedades de la Retina/etiología , Enfermedades de la Retina/fisiopatología , Adulto , Progresión de la Enfermedad , Estudios de Seguimiento , Hematócrito , Humanos , Masculino , Persona de Mediana Edad , Oftalmoscopía , Pacientes Ambulatorios , Fotograbar , Arteria Retiniana/patología , Enfermedades de la Retina/patologíaRESUMEN
BACKGROUND/AIMS: To assess the relative influence of genetic and environmental factors on retinal arterial tortuosity and the association between tortuosity and various health indices in healthy young to middle-aged persons. METHODS: This cross-sectional study included 57 monozygotic and 52 dizygotic same-sex healthy twin pairs, aged 20 to 46 years, who were characterised by determination of retinal vessel diameters, arterial blood pressure, blood glucose, body mass index, smoking habits and retinal arterial tortuosity, using a three-level grading scale (straight, wavy, tortuous). Heritability of retinal arterial tortuosity was estimated using structural equation modelling. RESULTS: Of 218 subjects, 79 (36.2%) had straight retinal arteries, 110 (50.5%) had wavy arteries, and 29 (13.3%) had tortuous arteries. Heritability of tortuosity was 82% (CI(95 )64, 92%), with unshared environmental factors accounting for the remaining 18% (CI(95 )8, 36%). Increasing values of mean arterial blood pressure and body mass index were both associated with decreasing levels of retinal arterial tortuosity. CONCLUSION: There was a large variation in tortuosity of retinal arteries in these healthy subjects and the predominant determinant was genetic influence, accounting for 82% of the observed variation in tortuosity.
Asunto(s)
Presión Sanguínea/fisiología , Arteria Retiniana/anatomía & histología , Gemelos Dicigóticos/fisiología , Gemelos Monocigóticos/fisiología , Adulto , Glucemia/análisis , Presión Sanguínea/genética , Índice de Masa Corporal , Estudios Transversales , Ambiente , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fumar/patología , Gemelos Dicigóticos/genética , Gemelos Monocigóticos/genéticaRESUMEN
We hypothesized that because depletion of vitamin A blocks the initiation of phototransduction, such inhibition of functional activation should lead to decrease retinal metabolism and perfusion. In a case study of a vitamin A-depleted patient, we found that retinal vessel diameters, a surrogate measure of retinal perfusion, increased in concert with the restitution of electroretinographic function following vitamin A supplementation. When normalized to conditions after treatment, the relative magnitude of study parameters at presentation were: scotopic electroretinography B-wave amplitude 1.2%, photopic electroretrinography B-wave amplitude 23%, retinal vein diameter 88%, retinal artery diameter 94%. These observations support that activation of the visual process results in increased retinal metabolism and perfusion.