Effects of AGN 192024, a new ocular hypotensive agent, on aqueous dynamics

PURPOSE: To determine the mechanism of intraocular pressure lowering for th e Ocular Hypotensive Lipid, AGN 192024 (Allergan, Inc, Irvine, California). METHODS: Twenty-five normal human volunteers between the ages of 21 and 48 took part in a randomized, double masked, placebo controlled, paired-compar ison study in which intraocular pressure, aqueous humor now, and tonographi c resistance to outflow were studied. Measurements of aqueous flow were mad e during the day and at night while subjects slept. Intraocular pressure wa s measured with the Goldmann tonometer, and resistance to outflow was measu red by electronic recording Schiotz tonography. RESULTS: Intraocular pressure was decreased by 20% on day 3 in AGN 192024-t reated eyes in comparison with placebo-treated eyes in normal subjects (P < .001). Aqueous humor flow was stimulated 13% during the day (P = .007) and 14% at night (P = .014) by the drug. Tonographic resistance to outflow was decreased 26% by AGN 192024 (P < .001), and apparent resistance to outflow (the ratio of intraocular pressure to aqueous now) was decreased 31% (P < .001). Assuming that AGN 192024 does not cause prolonged lowering of episcl eral venous pressure, the results show that pressure-insensitive outflow is enhanced by 50%, whereas tonographic facility of outflow (reciprocal of re sistance) was enhanced 35%, CONCLUSIONS: AGN 192024 is an ocular hypotensive agent that works by enhanc ing both pressure-sensitive and pressure-insensitive aqueous humor outflow without diminishing aqueous humor formation. (C) 2001 by Elsevier Science I nc.