Table 1 shows demographic data. There were no significant differences in gender, HbA1c, duration of diabetes, SBP, DBP, IOP, HR, Hb, total cholesterol, triglyceride, or LDL among the groups, while there were significant differences in age (p = 0.001), serum creatinine (p < 0.001), and eGFR (p < 0.001) among the groups. Here, GSTM1 is linked to diabetes mellitus.