Efforts to avoid systemic effects of THC in glaucoma treatment led to studies of topical preparations, such as 1 percent THC in peanut oil. However, no effect of the preparation on IOP was found by Jay and Green (big bud feminized). Animal studies have yielded conflicting results about the mechanism of action of THC on the IOP. The studies by Green in rabbits suggested central effects mediated through the adrenergic nervous system (Green 1979), but the studies of Colasanti (1990) in cats indicated no effect of either sympathetic or parasympathetic denervation on the action of THC. She also found that THC has no effect on aqueous production in anesthetized cats, but rather increased aqueous outflow facility threefold.