MR analysis demonstrated significant associations between Cathepsin H cis-eQTLs and increased risks of DR (OR = 1.0622, 95% CI = 1.0296–1.0958, P = 1.0 × 10− 4), PDR (OR = 1.0671, 95% CI = 1.0328–1.1026, P = 9.99 × 10− 5), and diabetic maculopathy (OR = 1.1273, 95% CI = 1.0654–1.1928, P = 3.17 × 10− 5). This evidence concerns the gene CTSH and diabetic maculopathy.