title: Choroidal blood flow after isovolemic hemodilution in an eye with retinal vein occlusion and the contralateral healthy eye.
abstract: OBJECTIVE
  To evaluate the effect of hemodilution on subfoveal choroidal blood flow in the human eye with or without retinal vein occlusion.
  
  
  METHODS
  Choroidal blood flow was measured using laser Doppler flowmetry in 28 patients with retinal vein occlusion in 1 eye. Isovolemic hemodilution was performed when hematocrit was >35%. Laser Doppler flowmetry parameters, velocity, volume, and flow were measured in both eyes in 4 sessions: 1 hour before and 1 hour after the first hemodilution on Day 1 and Day 7.
  
  
  RESULTS
  Hematocrit decreased significantly by 23.7%, 19.8%, and 16.1% in the first hour, on the first day, and the seventh day after hemodilution, respectively (P < 0.001). The ocular perfusion pressure of the healthy eye and the eye with retinal vein occlusion decreased by 7.7% and 7.2% after 1 hour and by 5.3% and 4.7% 1 day after hemodilution, respectively (P < 0.01). After hemodilution, subfoveal choroidal blood velocity, volume, flow, and vascular resistance did not significantly change in either eye.
  
  
  CONCLUSIONS
  Laser Doppler flowmetry measurement in the subfoveal choroid is a feasible technique for blood flow assessment in patients with retinal vein occlusion. A substantial change of hematocrit after isovolemic hemodilution does not lead to a significant change in choroidal blood flow. Vascular regulation is expected to keep blood flow constant and needs to be further explored.
authors.affiliation: Department of Ophthalmology, University Hospital of Grenoble, Joseph Fourier University, Grenoble, France. cchiquet@chu-grenoble.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Chiquet
authors.forename: Matthieu
authors.initials: M
authors.lastname: Tonini
authors.forename: Philippe
authors.initials: P
authors.lastname: Drillat
authors.forename: Viviane Vinh Moreau
authors.initials: VV
authors.lastname: Gaudry
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Romanet
authors.forename: Martial Henri
authors.initials: MH
authors.lastname: Geiser
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002829:Choroid / Q000098:blood supply*; D005260:Female; D005451:Fluorescein Angiography; D006339:Heart Rate / Q000502:physiology; D006400:Hematocrit; D006438:Hemodilution; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D009799:Ocular Physiological Phenomena; D010865:Pilot Projects; D012039:Regional Blood Flow; D012170:Retinal Vein Occlusion / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity