Figure 5. Measurement of blood–retinal barrier breakdown by Evans blue. A: Bar graph show standard curve for Evans blue concentration in formamide (background-subtracted absorbance at 620–740 nm; concentration from 1 to 80 μg/ml). B: Histogram shows retinal Evans blue leakage in diabetic rats at different times. *Values of treatment were compared to that of normal control * p value <0.05, ** p value<0.01. Values of treatment were compared to that of paired control # p value <0.05, ## p value<0.01