title: Effects of topical epinephrine on aqueous humor dynamics in the cat.
abstract: The purpose of this study was to investigate, in cats, the effects of topical epinephrine on aqueous humor dynamics as measured by the non-invasive method of fluorophotometry and by other methods. Measurements were carried out on 12 cats before and after one week of twice daily treatment with 2% epinephrine hydrochloride to one eye. Aqueous flow and outflow facility were determined using fluorophotometry. Uveoscleral outflow was calculated from these results and was evaluated with anterior chamber perfusion of FITC-dextran. Outflow facility also was measured by tonography. Epinephrine-treated eyes, compared with their baseline values, showed a 31% reduction in intraocular pressure (P<0.001), a 23% reduction in aqueous flow (P<0.05), a 60% increase in fluorophotometric outflow facility (P<0.05), and a 43% increase in tonographic outflow facility (P<0.05). Treated eyes, compared with contralateral control eyes, showed a 27% reduction in IOP (P<0.005), a 25% reduction in aqueous flow (P<0.005), a 38% increase in fluorophotometric outflow facility (P<0.05), and a 34% increase in tonographic outflow facility. When evaluated by both fluorophotometry and FITC-dextran tracer methods, epinephrine had no significant effect on uveoscleral outflow. It was concluded that, in cats treated with topical epinephrine twice daily for a week, a reduction in intraocular pressure is induced by an increase in outflow facility and decrease in aqueous flow.
authors: The Department of Ophthalmology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5540, USA.
authors: Y L
authors: YL
authors: Wang
authors: C B
authors: CB
authors: Toris
authors: G
authors: G
authors: Zhan
authors: M E
authors: ME
authors: Yablonski
mesh_terms: D000287:Administration, Topical; D000322:Adrenergic Agonists / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D001082:Aqueous Humor / Q000187:drug effects* / Q000502:physiology; D002415:Cats; D004837:Epinephrine / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D015590:Fluorophotometry; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male
chemical_list: D000322:Adrenergic Agonists; D004837:Epinephrine