Application Of Color Doppler Flow Imaging In The Hemodynamic Study Of Central Retinal Artery, Central Retinal Vein And Ophthalmic Artery In Diabetic Patients

IntroductionDiabetes Mellitus(DM) is a complicated metabolic disease. Small blood vessel is involved early,and many organs will be injured gradually.Diabetic retinopathy is one of the DM's main complications,is a main kind of disease which may cause blindness.Since the early 1990s',color Doppler flow imaging has been applied to the study of ocular hemodynamics in the DM patients.However,up to now,the study results aren't uniform completely.We examined 46 patients with DM and 55 healthy volunteers,so as to observe hemodynamic changes of central retinal artery, central retinal venous and ophthalmic artery in diabetic patients,to understand relations between hemodynamic changes and plasma glucose or durations.Materials and methodsHemodyanmic parameters of CRA, CRV and OA was determined in 55 healthy volunteers(100 eyes) and 46 diabetic patiens(92 eyes) by color Doppler flow imaging(CDFI). On the basis of funduscopic examination,46 diabetic patients was divided into two subgroups:31 patients (62 eyes)without retinopathy(NDR) and 15 patients(30 eyes)with background diabetic retinopathy(BDR).Hemodynamic parameters were compared among groups.Fast blood glucose,postprandial blood glucose,HbAlc were tested in all diabetic patients.Results1. Comparing with those of normal group,the blood flow velocity parameters of CRA and the end diastolic velocity (EDV)of OA in diabetic patients decreased signiflcantly,the maximum velocity(Vmax) of CRV in diabetic patients increased significantly .The resistance index(RI) and pulsatility index(PI) increased significantly.2. No significant difference were seen in peak systolic velocity(PSV), mean blood velocity(Vm) of OA among three groups(normal, NDR , BDR). The blood flow velocity parameters of CRA in NDR group were significantly lower than that in normal group,But the PK RI of CRA, CRV and OA were significantly higher .With the progression of early diabete,the blood flow velocity parameters of CRA and the end diastolic velocity (EDV)of OA decreased gradually,but the maximum velocity (Vmax) of CRV and PK RI of three observed vessels increased gradually.3.There is a negative correlation between EDV of CRA, OA and glycosylated hemoglobin(HbAlc), a positive correlation between RU PI and HbAlc.No correlations was found between blood flow parameters and FBG, PBG4.The blood flow velocity parameters of CRA and Vmin, EDV of OA were correlated with diabetic duration negatively,but Vmax,RI,PI,S/D of CRV and RI of OA was correlated with duration positively.ConclusionsWith the application of CDFI in measurement of CRA,CRV and OA,We can observe the pathophysiological conditions of retinal and choroid microcirculation.It can provide theoretic evidence for early detection , prevention, treatment of diabetic retinopathy clinically.Blood glucose and duration are the main factor which influence the ocular hemodynamics.