title: Trabecular outflow facility and formation rate of aqueous humor during intravenous cocaine or lidocaine in rabbits.
abstract: This study examined the effect of cocaine and lidocaine on intraocular pressure (IOP), fluid formation, outflow facility, and compliance. Fourteen New Zealand White rabbits were anesthetized with halothane (0.8-1.0% inspired concentration) in nitrous oxide (2 L/min) and oxygen (1 L/min). Pancuronium was given intravenously (i.v.) to produce neuromuscular block, and the lungs were mechanically ventilated through a tracheal tube. In one group (n = 8) cocaine 0.5 mg/kg followed by 1.0 microgram.kg-1.min-1 i.v. was added to halothane/nitrous oxide/oxygen anesthesia. In the second group (n = 6) lidocaine 0.5 mg/kg followed by 1.0 microgram.kg-1.min-1 i.v. was added to halothane/nitrous oxide/oxygen anesthesia. In both groups a series of intraocular infusions was made via a 30-gauge needle in the anterior chamber and IOP, the rate of aqueous humor formation, trabecular outflow facility, and intraocular compliance were determined. In Group I, IOP was 15.0 +/- 6.3 mmHg prior to and 14.5 +/- 7.1 mm Hg after cocaine. The rate of anterior chamber aqueous formation was 3.79 +/- 1.25 microL/min and trabecular outflow facility was 0.141 +/- 0.090 microL.min-1.mm Hg-1. In Group 2, IOP was 14.4 +/- 4.8 mm Hg prior to lidocaine and IOP decreased (P < 0.05 compared to precocaine in Group 1 and prelidocaine in Group 2) to 11.9 +/- 6.8 mm Hg after lidocaine. The rate of anterior chamber aqueous formation was 2.59 +/- 0.86 microL/min and trabecular outflow facility decreased (P < 0.05 compared to Group 1) to 0.077 +/- 0.040 microL.min-1.mm Hg-1. Intraocular compliance during cocaine, 36 +/- 12 nL/mm Hg, was similar to that during lidocaine, 33 +/- 14 nL/mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anesthesiology, University of Washington School of Medicine, Seattle 98195.
authors.forename: A A
authors.initials: AA
authors.lastname: Artru
mesh_terms: D000771:Anesthesia, Intravenous; D000779:Anesthetics, Local; D000818:Animals; D001082:Aqueous Humor / Q000187:drug effects*; D003042:Cocaine; D008012:Lidocaine; D011817:Rabbits; D014129:Trabecular Meshwork / Q000187:drug effects / Q000502:physiology*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D003042:Cocaine