While the association between HbA1c and progression of DR may resemble that seen in type 1 diabetes after initiating intensive insulin treatment or in T2D with tight blood glucose control,22,23 the reduction of risk in sight-threatening DR complications also occurs even in the shorter term using these agents.22,23 GLP-1 RAs may exert direct and indirect benefits on diabetic complications, primarily through improved glycemic control, which is reflected by decreased HbA1c levels. This evidence concerns the gene GLP1R and type 1 diabetes mellitus.