title: Ocular blood flow before, during, and after vitrectomy determined by laser speckle flowgraphy.
abstract: OBJECTIVE
  Vitrectomy markedly alters the intraocular milieu, which can then affect the physiology of the retina and choroid. This study investigates whether vitrectomy also alters ocular blood flow as determined by laser speckle flowgraphy (LSFG).
  
  
  METHODS
  Twenty eyes of 20 patients that underwent vitrectomy for idiopathic macular hole or epiretinal membrane were studied. Standard 23-gauge microincision vitreous surgery was performed. Ocular blood flow of the optic nerve head, retinal vessels, and choroid was determined by LSGF before, during, and 2 weeks and 1 month after vitrectomy.
  
  
  RESULTS
  Postoperative blood flow of the optic nerve head, retinal vessels, and choroid did not differ significantly from preoperative values. Intraoperative blood flow of the optic nerve head and retinal vessels decreased significantly from baseline with increasing infusion pressure from 20 mm Hg to 40 mm Hg (P < .01), and choroidal blood flow decreased significantly when the infusion pressure increased from 8 mm Hg to 20 mm Hg and from 20 mm Hg to 40 mm Hg (both P < .01).
  
  
  CONCLUSIONS
  Blood flow did not differ significantly postoperatively versus preoperatively, but it was significantly reduced during vitrectomy with increasing infusion pressure. Careful attention should be paid to infusion pressure during vitrectomy.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okamoto
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Matsuura
authors.forename: Nahoko
authors.initials: N
authors.lastname: Ogata
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002829:Choroid / Q000098:blood supply*; D019773:Epiretinal Membrane / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000098:blood supply*; D018918:Phacoemulsification; D012039:Regional Blood Flow / Q000502:physiology; D012167:Retinal Perforations / Q000503:physiopathology / Q000601:surgery*; D012171:Retinal Vessels / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology; D014821:Vitrectomy