A Study on Microcirculation Time Including Retinal Periphery in Diabetic Retinopathy using the Fluorescein Angiography

ABSTRACT

On video fluorescein angiogram, it is known that arm-to-retinal circulation(ART)influences retinal macrocirculation and arterio-venous passage time(AVP)influences microcirculation.In diabetic retinopathy(DR), midperiphery involved earlier than posterior pole.However, there has been no study on the circulation of the entire retinal circulation including the peripheral retina. The authors conducted a prospective study by performing fluorescein angiography on 19 controls and 19 DR patients in order to measure the ART, AVP and venous filling time(VFT). The VFT correspond to the circulation of the peripheral retina. In the DR group, the retina circulation time was compared with the existence of proliferative diabetic retinopathy(PDR), distribution of nonperfusion area and beading vessels. There was no significant difference between diabetic group and the control group in the ART.AVP was 1.8+/-0.7sec in the control group and 2.5+/0.7sec(p=0.04)in the DR group and venous filling time was 6.4+/-2.4sec and 8.9+/-1.5sec(p=0.006)respectively. Patients with PDR showed prolongation only in VFT compared to patients with non-proliferative diabetic retinopathy(NPDR). In addition, patients presenting with nonperfusion areas and beading of vessels showed longer prolongation of VFT than of AVP. In conclusion, the VFT is delayed in DR compared to control group and in PDR compared to NPDR. The VFT can be utilized as an indicator of DR to measure the retinal circulation including the peripheral retina.