title: Ocular blood flow velocity determined by color Doppler imaging in diabetic retinopathy.
abstract: OBJECTIVE
  To measure and investigate changes of blood flow velocity by color Doppler imaging in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (PCA) in diabetic retinopathy (DR) and to compare the results with those in healthy control subjects.
  
  
  METHODS
  In this investigation we included 44 eyes of 44 diabetic patients with different stages of DR forming group NPDR (11 eyes with mild and 11 eyes with moderate nonproliferative DR) and group SNPDR/PDR (19 eyes with severe nonproliferative and 3 eyes with proliferative DR) and 22 eyes of 22 healthy age- and sex-matched subjects forming control group HC. With color Doppler imaging we measured the peak systolic velocity (PSV, cm/s) and end-diastolic velocity (EDV, cm/s) of blood flow in the OA, CRA and PCA. The resistance index of each vessel was then calculated. Statistical analysis comparing the results of groups NPDR, SNPDR/PDR and HC was carried out. Statistical significance was set at p < 0.05.
  
  
  RESULTS
  There was a statistically significant increase in PSV in the OA in group SNPDR/PDR compared with group HC (35.71 +/- 6.90 vs. 31.45 +/- 4.32 cm/s; mean +/- SD). There was a statistically significant decrease in PSV in the CRA in group NPDR compared with group HC (8.50 +/- 1.62 vs. 10.61 +/- 1.75 cm/s; mean +/- SD) and in group SNPDR/PDR compared with group HC (7.34 +/- 1.78 vs. 10.61 +/- 1.75 cm/s; mean +/- SD), also there was a statistically significant decrease in EDV in group SNPDR/PDR compared with group HC (2.05 +/- 0.53 vs. 3.00 +/- 0.81 cm/s; mean +/- SD). A statistically significant decrease in EDV in the PCA in group SNPDR/PDR compared with group HC (2.95 +/- 1.04 vs. 3.95 +/- 0.98 cm/s; mean +/- SD) was found, also there was a statistically significant increase in the resistance index in group SNPDR/PDR compared with group NPDR (0.72 +/- 0.05 vs. 0.67 +/- 0.07; mean +/- SD) and in group SNPDR/PDR compared with group HC (0.72 +/- 0.05 vs. 0.67 +/- 0.05; mean +/- SD).
  
  
  CONCLUSIONS
  In this investigation, color Doppler imaging was used to determine significant changes of blood flow velocity in the OA, CRA and PCA in DR compared with healthy control subjects and the changes of blood flow velocity become further significant considering the progression of DR. This points to the presence of circulatory changes in the OA, CRA and PCA in diabetic patients with DR.
authors.affiliation: Department of Ophthalmology, Maribor Teaching Hospital, Maribor, Slovenia. tomaz.gracner@sb-mb.si
authors.forename: Tomaz
authors.initials: T
authors.lastname: Gracner
mesh_terms: D001783:Blood Flow Velocity; D019842:Ciliary Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D005123:Eye / Q000098:blood supply*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging / Q000469:parasitology; D012039:Regional Blood Flow; D012161:Retinal Artery / Q000000981:diagnostic imaging / Q000502:physiology; D018615:Ultrasonography, Doppler, Color