Figure 6

The numbers of intercapillary spaces with an increased area/perimeter ratio. (A) The numbers of intercapillary spaces with an area/perimeter ratio greater than 0.025 (A.U.) increase according to the DR severity grades. *P < 0.05, **P < 0.01 versus nondiabetic eyes. ^†P < 0.05 versus no apparent retinopathy or mild NPDR. The ROC curves to discriminate referable DR from no apparent retinopathy and mild NPDR (B); severe NPDR and PDR from no apparent retinopathy, mild NPDR, and moderate NPDR (C); and PDR from NPDR (D). The AUC shows the significant power of intercapillary spaces with an area/perimeter ratio greater than 0.025 (A.U.) to discriminate referable DR from no apparent retinopathy and mild NPDR.