Fig. 2

Characterization of retinal vessel in the POI and control groups.Nipping,arteriole-venous nipping;Aocclusion,arteriole occlusion;Tortuosity,tortuosity; Hemorrhage,hemorrhages; Exudates, exudates;Aasym, asymmetry index of arterioles; Vasym, asymmetry index of venules;BCV,bifurcation coefficient of venule; BCA,bifurcation coefficient of arterioles; Vangle, bifurcation angles of venule; Aangle,bifurcation angles of arterioles;CRAE,central retinal artery equivalent; CRVE,central retinal vein equivalent. AVR, CRAE to CRVE ratio; FDv,the fractal dimension of the retinal vasculature;arterioles FDa, the fractal dimension of the retinal arterioles