Science Cannabis

166 THE SCIENCE OF MARIJUANAFigure 4.4. Double-blind placebo controlled trial of smoked marijuana(2% THC content) versus placebo cigarettes in 18 patients with glaucoma,measuring intraocular pressure (IOP). Results are mean values ± standarderror. From Merritt et al. (1980). Reprinted courtesy of Ophthalmalogy.IOP, which lasted for 3-4 hours. He concluded, as have most otherophthalmologists, that treatment of glaucoma with cannabis is impractical.Patients would have to smoke marijuana several times a day in orderto maintain lowered IOP, a regime that would not be practicable in viewof the psychoactive effects of the drug and its effects on cognitive function.There are no reports of controlled studies involving the long-termuse of marijuana in glaucoma patients, so it is impossible to assess