title: The effect of acetazolamide on different ocular vascular beds.
abstract: OBJECTIVE
  To assess the effect of acetazolamide (AZ) on different ocular vascular beds.
  
  
  METHODS
  In a prospective study, 32 healthy volunteers (16 male, 16 female) with a mean age of 23.9 ± 3.3 years (20-39 years) were included. Before and after intravenous administration of 1,000 mg AZ (single dose), ocular microcirculation parameters were measured every 20 min for 2 h. Retinal vessel diameters (VD) were measured by the retina vessel analyzer, blood flow (BF) in the neuroretinal rim by the laser doppler flowmeter according to Riva, and the parapapillary retinal BF by the scanning laser Doppler flowmeter. Additionally, the Langham ocular blood flow system was used to determine the ocular pulse amplitude (OPA) and the pulsatile ocular blood flow (pOBF). The measurements were correlated with systemic blood pressure (BP), ocular perfusion pressure (OPP), capillary base excess parameters and serum AZ levels.
  
  
  RESULTS
  Arterial and venous VD were significantly increased by about 4-5% each. Papillary BF increased significantly about 40%. Parapapillary retinal flow dropped significantly about 19% (120 min). OPA and pOBF showed no statistically significant changes. BP showed no significant changes, and OPP was significantly increased. There were no correlations with pH or systemic perfusion parameters.
  
  
  CONCLUSIONS
  AZ leads to a dilatation of retinal VD, to an increase of BF in the optic nerve head, and to a decrease of parapapillary retinal BF. The different BF changes in different vascular beds might be due to different regulatory mechanisms, steal effects, or different distributions of the carbonic anhydrase.
authors.affiliation: Department of Ophthalmology, University of Dresden, Dresden, Germany. michael.haustein@uniklinikum-dresden.de
authors.forename: Michael
authors.initials: M
authors.lastname: Haustein
authors.forename: Eberhard
authors.initials: E
authors.lastname: Spoerl
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Boehm
mesh_terms: D000086:Acetazolamide / Q000008:administration & dosage*; D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007275:Injections, Intravenous; D007429:Intraocular Pressure / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D009898:Optic Disk / Q000098:blood supply; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000187:drug effects*; D012161:Retinal Artery / Q000502:physiology*; D012169:Retinal Vein / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects*; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D000086:Acetazolamide