title: Ocular hemodynamic effects of acute ethanol ingestion.
abstract: OBJECTIVE
  Because the protean biological effects of ethanol include acute alterations in both cortical function and circulatory control, we investigated the effect of acute alcohol consumption on retrobulbar hemodynamics and contrast sensitivity in healthy human volunteers.
  
  
  METHODS
  Twelve young adults received orange juice with and without ethanol in a double-masked fashion. The ethanol dose was sufficient to raise blood alcohol to 0.07 +/- 0.003 g/dl. Retrobulbar hemodynamics were assessed at baseline and twice at elevated blood alcohol by color Doppler imaging.
  
  
  RESULTS
  Acute elevation of blood alcohol lowered intraocular pressure from 13.0 +/- 0.7 to 10.7 +/- 0.7 mm Hg (p < 0.05). In contrast, elevated blood alcohol left peak systolic velocity, end-diastolic velocity and the resistance index constant in three retrobulbar arteries (ophthalmic, central retinal and posterior ciliary). For example, in the central retinal artery, peak systolic velocity, end-diastolic velocity and the resistance index averaged 11.0 +/- 1.3 cm/s, 2.8 +/- 0.4 cm/s and 0.75 +/- 0.03 before ethanol, as compared with 10.5 +/- 1.0 cm/s, 2.9 +/- 0.3 cm/s and 0.72 +/- 0.03 after ethanol (all p = NS). Alcohol ingestion also failed to alter either visual acuity or contrast sensitivity, as assessed under both photopic and mesopic conditions.
  
  
  CONCLUSIONS
  Although ethanol has widespread cognitive and cardiovascular effects, at blood levels near legal definitions of intoxication we found it ineffective in altering either retrobulbar hemodynamics or contrast sensitivity.
authors.affiliation: Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, USA.
authors.forename: A
authors.initials: A
authors.lastname: Harris
authors.forename: D
authors.initials: D
authors.lastname: Swartz
authors.forename: D
authors.initials: D
authors.lastname: Engen
authors.forename: D
authors.initials: D
authors.lastname: Beck
authors.forename: D
authors.initials: D
authors.lastname: Evans
authors.forename: K
authors.initials: K
authors.lastname: Caldemeyer
authors.forename: B
authors.initials: B
authors.lastname: Martin
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D015350:Contrast Sensitivity / Q000187:drug effects; D018592:Cross-Over Studies; D000431:Ethanol / Q000494:pharmacology*; D005123:Eye / Q000098:blood supply / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure; D009799:Ocular Physiological Phenomena; D009880:Ophthalmic Artery / Q000187:drug effects* / Q000502:physiology; D012016:Reference Values; D012161:Retinal Artery / Q000187:drug effects* / Q000502:physiology; D016037:Single-Blind Method; D018615:Ultrasonography, Doppler, Color
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol