Directional Power Doppler (dPd) in early ocular vs. renal vascular changes in diabetes mellitus type II

Abstract

pDd identifies early hemodynamic abnormalities in diabetes. We evaluated renal and ocular hemodynamics in early to advanced stages of diabetic nephropathy. 131 diabetic patients (62±8 y) grouped according to kidney failure, were studied: D1 (8 ♂, 1 ♀): creatinine clearance (ClCr.) ≥90ml/min; D2 (23 ♂, 14 ♀): ClCr.=89–60; D3 (30 ♂, 14 ♀): ClCr=59–30; D4 (14 ♂, 5 ♀): ClCr.=29–15; D5 (17 ♂, 5 ♀):ClCr. <15. Controls (C, 16 ♂, 16 ♀) were also studied. pDd measured Resistance Index (RI) at renal interlobe level; eye study evaluated systolic peak speed and RI of retina central (RCA). In diabetics ocular RI was always increased compared to controls: C=0.61±0.04; D1=0.82±0.11 (p<0.05 vs. C); D2=0.78±0.12 (p<0.05 vs. C); D3=0.85±0.09 (p<0,05 vs. C, D2); D4 and D5=0.88±0.08 (p<0.05 vs. C, D2, D3). RI was not related to age, diabetes duration, BMI, blood pressure, renal volume, glomerular filtrate, proteinuria and glycemia in all groups. The RCA flow velocity resulted reduced in diabetic nephropathy since early stages: D1=10.5±2.1cm/s; D2=10.5±2.4; D3=11.7±3.4; D4=10.5±3.1; D5=9.9±2.6. Renal interlobe artery IR was near normal in D1 and D2 (0.68±0.07) and significantly increased in D3 (0.77±0.10), D4 (0.88±0.08) and D5 (0.94±0.06). Directional Power Doppler is capable to detect early ocular hemodynamic abnormalities in diabetic patients. Thus, dPd should be a useful tool to early identify diabetic nephtropathy.