title: Effect of topical ophthalmic dorzolamide(2%)-timolol(0.5%) solution and ointment on intraocular pressure in normal horses.
abstract: OBJECTIVE
  To compare the effect of commercially available solution and compounded ointment formulations of dorzolamide(2%)-timolol(0.5%) on intraocular pressure (IOP) of normal horses.
  
  
  METHODS
  Eighteen clinically normal horses.
  
  
  METHODS
  A randomized, masked prospective design was used with horses divided into two equal groups. One eye of each horse was selected for topical ophthalmic treatment with either 0.2 mL of dorzolamide(2%)-timolol(0.5%) solution or 0.2 g of dorzolamide(2%)-timolol(0.5%) ointment every 12 h for 5 days. The contralateral eye of horses in both groups was untreated. Rebound tonometry was performed every 6 h starting 2 days prior to and ending 2 days after the treatment period.
  
  
  RESULTS
  The mean IOP reduction in eyes treated with the solution or ointment formulations was 13%. Untreated eyes in both groups experienced a lesser but still statistically significant reduction in IOP. The IOP values did not return to baseline within 48 h of the last treatment.
  
  
  CONCLUSIONS
  The commercially available solution and compounded ointment formulations of ophthalmic dorzolamide(2%)-timolol(0.5%) had similar effects on IOP in normal horses. Persistent IOP reduction following cessation of treatment may indicate prolonged drug effect or acclimation of horses to tonometry.
authors.affiliation: Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: Kyle L
authors.initials: KL
authors.lastname: Tofflemire
authors.affiliation: Veterinary Pathology, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Whitley
authors.affiliation: Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Flinn
authors.affiliation: Terrington Veterinary Center, Terrington St. Clement, King's Lynn, PE34 4NE, UK.
authors.forename: Valerie L
authors.initials: VL
authors.lastname: Dufour
authors.affiliation: Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: Gil
authors.initials: G
authors.lastname: Ben-Shlomo
authors.affiliation: Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Allbaugh
authors.affiliation: Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: Angela N
authors.initials: AN
authors.lastname: Griggs
authors.affiliation: Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: Chimene S
authors.initials: CS
authors.lastname: Peterson
authors.affiliation: Department of Veterinary Clinical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, 50011, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Whitley
mesh_terms: D060433:Administration, Ophthalmic; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000627:therapeutic use; D000818:Animals; D004338:Drug Combinations; D005260:Female; D006736:Horses; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D009824:Ointments; D009883:Ophthalmic Solutions; D013449:Sulfonamides / Q000008:administration & dosage* / Q000627:therapeutic use; D013876:Thiophenes / Q000008:administration & dosage* / Q000627:therapeutic use; D013999:Timolol / Q000008:administration & dosage* / Q000627:therapeutic use; D014065:Tonometry, Ocular / Q000662:veterinary
chemical_list: D000319:Adrenergic beta-Antagonists; D004338:Drug Combinations; D009824:Ointments; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013876:Thiophenes; D013999:Timolol; C062765:dorzolamide
keywords: compounded medication; dorzolamide; horse; intraocular pressure; timolol