Effects of prostaglandin E2 and cholinergic drugs on intraocular pressure.

Effects of prostaglandin E2 (PGE2) and cholinergic drugs on intraocular pressure (IOP) have been studied in the rabbit. PGE2 injected intracamerally in a dose of 5 micrograms produced a long-lasting increase in IOP. Topical pretreatment with carbachol, physostigmine and pilocarpine abolished the rise of IOP after the intracameral injection of PGE2. When the IOP had already been increased by PGE2 topical application of pilocarpine and physostigmine did not change it. Carbachol even potentiated the pressor effect of PGE2. Topical application of cholinergic drugs only slightly increased protein content of the aqueous humor. Intracameral injection of PGE2 significantly increased protein content of the aqueous humor, and subsequent application of carbachol produced further elevation of protein content. On the other hand, when PGE2 was injected after topical application of cholinergic drugs, protein content was the same as after PGE2 alone. The relationship between PGE2 and cholinergic drugs regarding the IOP was thus demonstrated.