Ultra-widefield Fluorescein Angiography Compared With ETDRS 7-standard Fields Fluorescein Angiography For Evaluation Of Diabetic Retinopathy

Purpose:To evaluate the area of visualized retina and retinal pathology and to grading for patients with diabetic retinopathy(DR)by comparing ultra-widefield fluorescein angiography(UWFFA)with Early Treatment Retinopathy Study(ETDRS)7-standard fields(7SF)fluorescein angiography.To characterize the correlaton between several common angiographic features of diabetic retinopathy.Methods:Seventy-one diabetic patients were included.Using the Optos 200 Tx imaging system to take ultra-widefield color images and angiography for each eye.Using the protocol for obtaining 7SF images as described in the ETDRS.Seven 30° circles were combined to create a digital 7SF template.This template was then overlaid on the UWFFA image to identify the potential viewable area of 7SF.One trained ophthalmologist analyzed each UWFFA and 7SF image and then measured viewable retinal area and the area of non-perfusion(NP)and retinal neovascularization(NV).Then,exploring the presence of peripheral vessel leakage(PVL)and peripheral non-perfusion in relation to diabetic macular edema(DME)and neovascularization.Finally,the consistency of the grading of DR was evaluated after analyzing all images with UWFFA and 7SF angiography by two trained ophthalmologists.Results:1.When compared with 7SF,UWFFA showed 3.05(0.57)times more total retinal area(t=7503.00,P<0.001),2.97(2.09)times more non-perfusion area(include NV)(t=347.00,P=0.009)which had significant difference.But UWFFA showed 1.00(0.18)times more neovascularization(t=777.50,P=0.737),1.15(0.32)times more non-perfusion area(exclude NV)(t=557.00,P=0.523)whichhad no significant difference.A total of 3 eyes were found to have neovascularization only outside the simulated 7SF boundary.2.PVL was associated with diabetic macular edema(P<0.0001,Contingency Coefficient=0.575).PVL was associated with neovascularization(P<0.0001,Contingency Coefficient=0.370).Peripheral non-perfusion was associated with neovascularization(P<0.0001,Contingency Coefficient=0.563).Peripheral non-perfusion was associated with diabetic macular edema(P<0.0001,Contingency Coefficient=0.387).3.Based on UWFFA,the results were as follows:no DR(n=14,[12.6%]),mild-NPDR(n=3,[2.7%]),moderate-NPDR(n=19,[17.1%]),severe-NPDR(n=42,[37.8%]),PDR(n=33,[29.7%]).Based on 7SF,the results were as follows:no DR(n=18,[16.2%]),mild-NPDR(n=0,[0%]),moderate-NPDR(n=21,[18.9%]),severe-NPDR(n=42,[37.8%]),PDR(n=30,[27.0%]).There was a good consistency between UWFFA and 7SF fluorescein angiography in the grading of DR(Kappa=0.876,P<0.001).Conclusions:1.Ultra-widefield fundus examination is much wider in observation.2.Non-perfusion area and peripheral vessel leakage of diabetic retinopat-hy located outside the conventional 7SF may have significance in clinical work.3.Ultra-widefield fluorescein angiography is more precise than conventi-onal 7SF fluorescein angiography in grading DR.