Ocular hypotensive effects of SCH23390 (selective dopamine D1 receptors antagonist) in POAG

Purpose. In our previous studies we reported that D1 dopaminergic agents increase IOP in presence of an intraocular hydrodynamic disorder. Such effect is antagonized by means of SCH23390, a selective D1 antagonist. The aim of the present paper was to evaluate if SCH23390 was able to decrease IOP in POAG Methods. 16 POAG patients underwent to a 15-day pharmacological wash-out. SCH23390 1% was administered topically in one eye, leaving the other eye as control. IOP was measured before (baseline) and 1 hour after SCH23390 administration Results. After 1 hour SCH23390 induced a significant decrease of IOP (5.6 mmHg SD 0.86) in 56% of treated eyes. The hypotensive effect was correlated to baseline value (R=0.6; p=0.02). In 44% of patients no significant change in IOP was observed Conclusions. These preliminary results open new trends in physio-parmacological studies of D1 dopaminergic antagonists and their potential application as antiglaucomatous agents. Further investigations will clarify the role of D1 receptors in aqueous humor dynamics