title: The effects of a fixed combination of 0.5% timolol and 1% dorzolamide on optic nerve head blood circulation.
abstract: OBJECTIVE
  The purpose of the present study is to evaluate the effects of a fixed combination of 0.5% timolol maleate (TM) and 1% dorzolamide hydrochloride (DZ) (FCTD(1%)) on optic nerve head (ONH) blood circulation.
  
  
  METHODS
  A drop of 0.5% TM, 1% DZ, or FCTD(1%) was topically administered to the right eyes of 15 healthy Japanese subjects, and a drop of saline was likewise administrated to their left eyes. Systemic blood pressure, heart rates (HRs), intraocular pressures (IOPs), ocular perfusion pressures, and blood circulation by a laser speckle flowgraphy at the ONH were measured before administration, and again at 1.5 and 6 h afterward.
  
  
  RESULTS
  FCTD(1%) caused a significant increase in ONH blood circulation 6 h after the administration, while 0.5% TM and 1% DZ had no significant effect. The IOPs were significantly decreased in 0.5% TM (P<0.01) and FCTD(1%) (P<0.05) when compared with the saline-treated eyes at 1.5 and 6 h after administration, while 1% DZ did not show a statistically significant decrease. There were no significant changes in other systemic parameters except for a significant transient decrease in the HRs observed in 0.5% TM (P<0.01) when compared with the baseline at 1.5 h after the administration.
  
  
  CONCLUSIONS
  Our current results suggest that FCTD(1%) caused a significant increase in ocular blood circulation on the ONH in healthy Japanese subjects, presumably by a synergistic effect of 0.5% TM and 1% DZ, although neither 0.5% TM nor 1% DZ on their own had a significant effect.
authors.affiliation: Department of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan. ooguro@sapmed.ac.jp
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Ohguro
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohguro
mesh_terms: D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology*; D004338:Drug Combinations; D004357:Drug Synergism; D005123:Eye / Q000098:blood supply / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D009883:Ophthalmic Solutions; D009898:Optic Disk / Q000098:blood supply* / Q000187:drug effects*; D010477:Perfusion; D012039:Regional Blood Flow / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology*; D013876:Thiophenes / Q000494:pharmacology*; D013999:Timolol / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists; D002257:Carbonic Anhydrase Inhibitors; D004338:Drug Combinations; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013876:Thiophenes; D013999:Timolol; C062765:dorzolamide