Figure 4. Correlation between erythrocyte sorbitol levels and aldose reductase activity. Correlation (r=0.188) between erythrocyte sorbitol levels and aldose reductase (ALR2) activity in control, diabetics without diabetic retinopathy (DNR), and diabetics with retinopathy (DR) was found to be significant at p<0.05. Correlation was done for those samples in which sorbitol was determined.