Changes in Retinal Circulation Time after Panretinal Photocoagulation in Patients with Nonproliferative and Proliferative Diabetic Retinopathy

ABSTRACT

Purpose@#To explore whether panretinal photocoagulation (PRP) improved retinal blood circulation in patients with diabetic retinopathy of various levels of severity based on changes in the retinal circulation time as measured by video fluorescein fundus angiography. @*Methods@#We recruited patients with severe diabetic retinopathy indicated for PRP; we performed video fluorescein fundus angiography before and after PRP. We measured changes in the arterial circulation time (ACT), arteriovenous passage time (APT), and venous filling time (VFT) in patients with diabetic retinopathy of varying severity, and compared the findings. We recorded HbA1c levels and hypertension status. @*Results@#We enrolled 33 patients, 17 with severe nonproliferative diabetic retinopathy (NPDR) and 16 with early proliferative diabetic retinopathy (PDR). After PRP, neither the ACT nor the APT changed significantly in patients with severe NPDR (p = 0.927, p = 0.138) or early PDR (p = 0.137, p = 0.268). After PRP, the VFT was significantly reduced in patients with both severe NPDR (p = 0.000) and early PDR (p = 0.022). The VFT reductions were similar in both groups (p = 0.217). @*Conclusions@#In patients with severe NPDR and early PDR, improvements in retinal blood circulation after PRP are reflected by reductions in the VFT evident on video fluorescein fundus angiography. We speculate that the improvements are similar in patients with severe NPDR and early PDR.