NR3C1 and open-angle glaucoma: While chronic glucocorticoid (GC) therapy leads to ocular hypertension in about one third of individuals, almost all primary open-angle glaucoma (POAG) patients show this response and are called “steroid responders.” Two differentially spliced isoforms of the glucocorticoid receptor (GR), GRα and GRβ, regulate GC responsiveness in trabecular meshwork (TM) cells.