Vascular network changes in the retina during ageing in normal subjects: a computerized quantitative analysis.

BACKGROUND: Direct ophthalmoscopic examination of fundus oculi is widely used for the qualitative evaluation of target organ damage in several pathological conditions. At present, there are no reliable techniques available to quantify retinal vascular damage. The aim of this study was to develop a computerized technique for the quantitative analysis of fundus oculi. METHODS: We studied 68 non-smoking, normotensive normal subjects, with a visual acuity > 8/10. From each subject retinal images were taken using a non-mydriatic ophthalmoscope and digitized onto a personal computer. In each image the area of analysis was set to a circular selection, corresponding to 25% of the whole fundus oculi, concentric with the optic disc. From each selection arterial and venous area and mean arteriolar bifurcation angle were obtained. Measurements were taken in a blinded way by two operators and, by the same operator, twice at different times. Parameters were correlated with age and body surface area. RESULTS: Retinal arterial density (arteries 7.44 +/- 1.25%; bifurcation angle 75 +/- 16 degrees) was significantly correlated with age, but not with body surface area. Intra- and interobserver coefficient of variation resulted 2.5 and 3.2%, respectively. CONCLUSIONS: Computerized analysis of the fundus oculi with the evaluation of vascular density indexes represents a simple and reproducible technique that could be useful in identifying changes in retinal vascular network during ageing.

Blood pressure-independent cardiac hypertrophy in acromegalic patients.

OBJECTIVE: Acromegaly is frequently associated with an increase in left ventricular mass, even in the absence of systemic hypertension. Pathological studies on acromegalic hearts have shown an extensive interstitial fibrosis, suggesting the existence of a specific acromegalic cardiomyopathy. The aim of this study was to assess left ventricular wall structure in acromegaly by ultrasonic tissue characterization. DESIGN AND METHODS: We studied 10 untreated acromegalic patients and 10 age-matched healthy control subjects. The echo patterns of two-dimensional long-axis end-diastolic echocardiograms were assessed by colour-scale analysis of the interventricular septum, with estimates of the mean colour scale value, the broad band (Bb) and the derived collagen volume fraction (dCVF). We also measured electrocardiographic QT interval dispersion (QTd) as a marker of dyshomogeneous ventricular repolarization. RESULTS: Seven patients had left ventricular hypertrophy according to the sex-independent criteria; of these, two had arterial hypertension. None of our patients had echocardiographic evidence of diastolic or systolic dysfunction. All patients showed significantly increased myocardial echoreflectivity (Bb = 106.4+/-12.1 versus 79.3+/-6.5; dCVF% = 2.78+/-0.53 versus 1.58+/-0.29; P < 0.0001) and QTd (66+/-13 ms versus 54+/-8 ms, P < 0.05). A significant correlation was found between dCVF and the duration of acromegaly (r = 0.80; P = 0.005). CONCLUSIONS: Left ventricular remodelling observed in acromegaly is not related to the presence of arterial hypertension; we hypothesize that the increased echoreflectivity and QTd are long-term consequences of cardiac hypertrophy and prolonged exposure to high levels of growth hormone and insulin-like growth factor-I.