The DP-Receptor Agonist SQ27986 Raises but Does Not Lower Intraocular Pressure in Ocular Normotensive Monkeys

rostaglandin (PG) D2 and the DP-receptor selective analog BW245C have been shown to lower intraocular pressure (IOP) in rabbits, monkeys, and man. In these experiments, the effects of the DP-receptor selective agonist SQ27986 on IOP, pupil diameter, and refractive error in ocular normotensive cynomolgus monkeys were tested. Single or repeated (three days of twice-daily) unilateral doses of SQ27986 produced a 2–6 mm Hg rise in IOP 15–120 min after administration, which was not followed by ocular hypotension. The SQ27986 had no effect on pupil diameter, refraction, or anterior segment biomicroscopic appearance. Although other DP-receptor agonists can lower IOP slightly in normotensive eyes and more substantially in hypertensive eyes by decreasing aqueous formation, the inability of SQ27986 to reduce IOP in our ocular normotensive monkeys suggests that DP-receptor stimulation does not increase uveoscleral outflow or play a major role in IOP reduction by other relatively nonselective prostaglandins such as PGF2α.