Prostaglandins E3 and D3 lower intraocular pressure

The effects of the prostaglandin (PG)-3 series products PGE3 and PGD3 on the intraocular pressure of rabbits were studied. PGE3 at 0.001 and 0.01 mg/eye and PGD3 at 0.01 and 0.05 mg/eye doses were applied topically (in 50-microliters volume) to the normal rabbit eye. Both PGE3 and PGD3 significantly lowered intraocular pressure at all doses tested and the IOP lowering response lasted at least 240 min. Topical PGE3 at 0.01 mg/eye caused mild conjunctival hyperemia which lasted up to 180 min. PGD3, on the other hand, did not induce conjunctival hyperemia. In addition, following application of these PGs, there was no miosis or other sign of intraocular inflammation detectable by slit-lamp examination.