title: Pulsatile ocular blood flow in untreated diabetic retinopathy.
abstract: OBJECTIVE
  To measure the pulsatile component of total ocular blood flow in patients with untreated diabetic retinopathy.
  
  
  METHODS
  An adapted pneumotonometer attached to a slit-lamp biomicroscope. 82 age-matched subjects divided into 4 groups: non-diabetic controls (n = 22); diabetics with no clinical retinopathy (n = 20); background diabetic retinopathy (n = 20); pre-proliferative/proliferative diabetic retinopathy (n = 20).
  
  
  RESULTS
  The mean pulsatile ocular blood flow values were found to be increased in all grades of diabetic retinopathy (no retinopathy 818 microl/min, background 1015 microl/min, pre-proliferative/proliferative 1097 microl/min) compared to the control group (644 microl/min). These pulsatile ocular blood flow values were significantly higher (p<0.05) in the background and pre-proliferative/proliferative retinopathy groups compared to controls. Pulse volume and pulse amplitude were also higher in the diabetic subjects. Mean arterial blood pressure did not differ across the groups studied.
  
  
  CONCLUSIONS
  Pulsatile ocular blood flow was found to be higher in diabetics compared to controls and appears to increase as the severity of retinopathy progresses. Such a hyperdynamic circulation may contribute to the pathogenesis of diabetic eye disease.
authors.affiliation: Princess Alexandra Eye Pavilion, Edinburgh, Scotland.
authors.forename: J R
authors.initials: JR
authors.lastname: MacKinnon
authors.forename: C
authors.initials: C
authors.lastname: O'Brien
authors.forename: K
authors.initials: K
authors.lastname: Swa
authors.forename: P
authors.initials: P
authors.lastname: Aspinall
authors.forename: Z
authors.initials: Z
authors.lastname: Butt
authors.forename: D
authors.initials: D
authors.lastname: Cameron
mesh_terms: D000368:Aged; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000503:physiopathology*; D005123:Eye / Q000098:blood supply*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D019722:Sphygmomanometers