DPP4 and type 2 diabetes mellitus: We conducted a nationwide cohort study to compare the risk of sight-threatening retinopathy (including severe diabetic retinopathy and macular edema) associated with SGLT2is and other second-line glucose-lowering medications (including pioglitazone, sulfonylureas, and dipeptidyl peptidase-4 inhibitors [DPP-4is]) in patients with T2D.