糖尿病大鼠视网膜血流动力学的彩色多普勒超声研究

Study on hemodynamics of retina in diabetic rats using colour Doppler ultrasound

目的应用彩色多普勒超声对糖尿病大鼠视网膜动、静脉血流及内径进行测定,探讨糖尿病大鼠视网膜血流动力学的变化规律。方法选取Wistar大鼠33只,Stroptozocin(STZ)诱导造模,造模前及造模后的每个月对大鼠视网膜中央动、静脉进行彩色多普勒超声检查,记录收缩期峰值血流速度(Peaksystolicvelocity,PSV)、舒张末期流速(Enddiastolicvelocity,EDV)、平均血流速度(Meanvelocity,MV)、搏动指数(Pulsatilityindex,PI)以及阻力指数(Resistanceindex,RI)等参数,连续观察6个月。结果1个月时,糖尿病大鼠视网膜中央动脉的MV、PI改变明显(P<0.01);2个月视网膜中央动脉内径增宽;3个月时PSV、EDV显著降低,5、6个月时RI、PI增高(P<0.05),血糖与PI相关(r=0.349,P=0.003)。结论在持续高血糖状态下,极早期MV即发生改变,随着病程延长,血流参数发生变化,因而,视网膜血流减少与血液灌注不良为糖尿病视网膜病变重要的发病因素。

Objective To investigate the retinal hemodya amics in the diabetic rats through detecting central retinal artery (CRA), central vein with color Doppler imaging.Methods Using 33 Wistar rats the blood stream and innerdiameter Stroptozocin-induced diabetic model was established.The circulatory para-meters of CRA of rat's eyes before experiment and after experiment were detected using color Doppler imaging for six months, including peak psystolic velocity (PSV),end diastolic velocity (EDV),mean velocity(MV),pulse index(PI), resistance index (RI) and diameter of the blood vessel(D). Results In 1st month, MV and PI in CRA changed significantly; in 2nd month, CRA diameter significantly increased;in 3rd month,PSV, EDV and blood velocity in the diabetic rats was lower significancy than that in the control, on the contrary, RI and PI in the diabetic rats was higher significancy.Conclusion The abnormal changes of retinal blood stream occur at early stage of Diabetes. The consistently decreased blood flow and poor perfusion of retinal blood are the important causes of diabetic retinopathy.