Aleksandra Mandecka

Abnormal retinal autoregulation is detected by provoked stimulation with flicker light in well-controlled patients with type 1 diabetes without retinopathy.

AIMS Investigation of retinal vasodilation under flickering light is considered a dynamic analysis in contrast to the static analysis of retinal vessel equivalents (mean retinal vessel diameter). We investigated whether dynamic analysis apart from the static one in type 1 diabetic patients without diabetic retinopathy with well-controlled diabetes could lead to additional information regarding retinal autoregulation. METHODS 18 normotensive type 1 diabetic patients without retinopathy and 19 healthy subjects were included. Diameter of retinal vessels was measured with Dynamic Vessel Analyzer. Changes in vasodilation are expressed as percent change over baseline values. RESULTS HbA(1c) was 7.5+/-1.0% in diabetic patients. In arteries, the response to flicker was diminished in diabetic patients compared to healthy volunteers (p<0.023). In patients flicker stimulation increased arterial diameter by +2.7% in contrast to +4.4% in controls. Venous vessel diameter increased by +3.1% in diabetic individuals and by +5.3% in the control group (p<0.002). There were no differences in static analysis between both groups. CONCLUSIONS Diabetic patients without retinopathy with relatively good glycemic control show reduced retinal vasodilation after flicker indicating dysfunction in retinal autoregulation. The use of provocation test in conjunction with static analysis could lead to additional information regarding abnormal retinal autoregulation.

Influence of Flickering Light on the Retinal Vessels in Diabetic Patients Response to Nguyen, Cheung, and Wong

OBJECTIVE Stimulation of the retina with flickering light increases retinal vessel diameters in humans. Nitric oxide is a mediator of the retinal vasodilation to flicker. The reduction of vasodilation is considered an endothelial dysfunction. We investigated the response of retinal vessels to flickering light in diabetic patients in different stages of diabetic retinopathy. RESEARCH DESIGN AND METHODS We studied 53 healthy volunteers, 68 type 1 diabetic patients, and 172 type 2 diabetic patients. The diameter of retinal vessels was measured continuously online with the Dynamic Vessel Analyzer (DVA). Diabetic retinopathy was classified using Early Treatment Diabetic Retinopathy Study criteria. Changes in vasodilation are expressed as percent change over baseline values. RESULTS After adjustments for age, sex, and antihypertensive treatment, the response of retinal arterioles to diffuse luminance flicker was significantly diminished in patients with type 1 diabetes compared with healthy volunteers. The vasodilation of retinal arterioles and venules decreased continuously with increasing stages of diabetic retinopathy. The retinal arterial diameter change was 3.6 +/- 2.1% in the control group, 2.6 +/- 2.5% in the no diabetic retinopathy group, 2.0 +/- 2.7% in the mild nonproliferative diabetic retinopathy (NPDR) group, 1.6 +/- 2.2% in the moderate NPDR group, 1.8 +/- 1.9% in severe NPDR group, and 0.8 +/- 1.6% in proliferative diabetic retinopathy group. CONCLUSIONS Flicker responses of retinal vessels are abnormally reduced in diabetic patients. This decreased response deteriorated with increasing stages of retinopathy. The response was already reduced before clinical appearance of retinopathy. The noninvasive testing of retinal autoregulation with DVA might prove to be of value in early detection of diabetic vessel pathological changes.

Dynamic Vessel Analyzer (DVA) – a new method to detect endothelial dysfunction in chronic heart failure: correlation between DVA and asymmetric dimethyl arginine (ADMA)

Background Chronic heart failure (CHF) is the leading cause of hospitalization and death in industrialized countries. CHF is frequently associated with humoral and metabolic disturbances, including reduced bioavailability of the important signalling molecule nitric oxide (NO), which has vasodilating properties. Several studies reported high plasma levels of asymmetrical NG, NG-dimethyl-L-arginine (ADMA), an endogenous inhibitor of NO production, in CHF, contributing to endothelial dysfunction. The Dynamic Vessel Analyzer (DVA) enables dynamic analyses of retinal vessels. NO is a mediator of retinal vasodilator response to flicker light. Reduced response of retinal arterioles to flicker light may be an attractive technique to non-invasively assess endothelial dysfunction. The aim of the study was to test the hypothesis that retinal vessel response to flicker light is reduced in patients with CHF and correlates inversely with serum ADMA levels.

Inflammatory Obstruction of the Ureter Caused by Infrarenal Aortitis

50-year-old man was admitted to the hospital becauseof diminished urinary stream and postvoid leakage. Theanamnesis was inconspicuous. Sonography revealed dilationof the left ureter with a hydronephrosis grade II. Computedtomography (CT) showed an infrarenal thickening of theaortic wall (Figure 1A and 1B, arrowhead) and proximalvessel wall of the iliaca communis of both arteries (Figure1C, arrowhead). Furthermore, direct surrounding wall thick-ening of the vessels obstructed the left ureter (Figure 1C,arrow) with dilation of the proximal left ureter (Figure 1A,arrow). The urography phase of CT confirmed a hydrone-phrosis grade II (Figure 1D, asterisk).For further characterization, an (18)F-fluorodeoxyglucosepositron emission tomography (PET)–CT of the whole body