An α2-adrenergic receptor agonist (Kis = 2.7, 52, and 44 nM for α2A, α2B, and α2C-ARs, respectively, in CHO cells); selective for α2-ARs over α1-ARs (Ki = 1,800 nM in human brain); topical application lowers intraocular pressure in DBA/2J mice, a glaucoma model, to control levels at 0.1% solution; inhibits glutamate release, prevents upregulation of NMDA receptors containing NR1 and NR2A subunits, and protects rat retinal ganglion cells against glutamate excitotoxicity in a rat model of retinal ischemia at 1 mg/kg per day