GLP1R and type 2 diabetes mellitus: Synthetic glucagon-like peptide-1 receptor (GLP-1R) agonists are a popular class of therapy for type 2 diabetes mellitus, which a number of studies have suggested may be a risk factor for glaucoma (Hayes et al., 2014; Zhou et al., 2014; Tella and Rendell, 2015; Zhao et al., 2015).