SOD1 and age-related macular degeneration: Accordingly, the drusen size in patients with AMD correlated positively with SOD, GPx and GSH transferase activities in RBCs (Rs = 0.31, p < 0.001; Rs = 0.16, p = 0.003; and Rs = 0.18, p < 0.001, respectively) and negatively correlated with both RBC activity and PLT GSH concentration (Rs = −0.27, p < 0.001; and Rs = −0.24, p < 0.001, respectively).