The Clinical Significance of Venous Filling Time through Panretinal Photocoagulation in Proliferative Diabetic Retinopathy

ABSTRACT

PURPOSE: To verify the clinical correlation between retinopathy progression and the change of venous filling time (VFT), measured before and after panretinal photocoagulation (PRP), in proliferative diabetic retinopathy (PDR) patients. METHODS: We conducted this study on 32 patients (32 eyes) who received PRP for PDR. These patients were subdivided into two groups in accordance with the clinical course of PRP the stabilized group in which retinal neovascularization was regressed and the progressed group in which retinal neovascularization was continued and a complication, such as vitreous hemorrhage or tractional retinal detachment, was developed within 12 months of laser treatment. Arteriovenous passage time (AVP) and VFT were measured by video fluorescein angiogram (FAG) using scanning laser ophthalmoscope (SLO) before and after PRP. VFT values were assigned by measuring by the time duration from start of venous lamina flow to the fullness of fluorescence on the vascular arch. RESULTS: In the stabilized group, AVP was decreased by 0.20+/-0.89sec and VFT was decreased by 0.30+/-1.69 sec through PRP. In the progressed group, AVP was increased in 0.12+/-1.22 sec and VFT was increased by 0.99+/-1.60 sec through PRP. In both groups, the VFT changes were significant (P=0.04) but the AVP changes were not (P=0.34). CONCLUSIONS: VFT was significantly decreased in the stabilized group and significantly increased in the progressed group after PRP. Accordingly, we suggest that VFT changes after PRP can be utilized as a prognostic indicator for evaluating clinical course of diabetic retinopathy after performing PRP and for monitoring the clinical effect of PRP.