CTSH and diabetic maculopathy: High levels of Cathepsin H increased the risk of DR (OR = 1.0496, 95% CI = 1.0155–1.0849, P = 4.1 × 10− 3), and other two subtypes of DR, including PDR (OR = 1.0587, 95% CI = 1.0233–1.0954, P = 1.0 × 10− 3) and diabetic maculopathy (OR = 1.075, 95% CI = 1.0176–1.1357, P = 9.8 × 10− 3), as shown in Fig. 3A. The WM method and the weighted model method further confirmed a significant association between higher Cathepsin H levels and an increased risk of DR, PDR and diabetic maculopathy (Fig. 3).