Figure 4. Illustration of the normal L-Asp 58 spontaneously converted to L-isoAsp 58, D-Asp 58, and D-isoAsp 58 in diabetic lenses. (A) The main difference in racemization at Asp residues in the lenses of DC patients was an increased percentage of D-Asp 58 in the cortex, leading to the early stage of cortical opacification in DC. (B) Over the protracted duration of diabetes, the percentage of D-isoAsp 58 in the nucleus increased, leading to the further nuclear opacification on the original basis of cortical opacification in the late stage of DC. L-Asp = L-Asp 58, L-isoAsp = L-isoAsp 58, D-Asp = D-Asp 58, D-isoAsp = D-isoAsp 58.