title: [Measurement of flow velocity in feeder vessels of choroidal neovascularization with a scanning laser ophthalmoscope and image analysis system].
abstract: OBJECTIVE
  To measure flow velocities in feeder vessels of choroidal neovascularization(CNV) secondary to age-related macular degeneration(AMD).
  
  
  METHODS
  We examined early images of indocyanine green(ICG) angiography in 29 eyes with CNV secondary to AMD, in which feeder vessels could be identified. ICG videoangiographic images recorded at 30 frames per second with a scanning laser ophthalmoscope were installed in a personal computer. With original software, optical density measurements made with an image analyzer were performed on ICG videoangiograms for determination of dye-dilution curves. The time(T50) from the beginning of a dye-dilution curve to the ascending parts of the curve at 50% of the peak intensity was calculated. Flow velocity in a feeder vessel was obtained by dividing the distance between two points by the circulation time between T50 s at the two points on the feeder vessel.
  
  
  RESULTS
  The mean flow velocity in feeder vessels was 33.8 +/- 32.5 (mean +/- standard deviation) mm/sec. The mean velocity in the feeder vessels of large CNV with greatest linear diameter of 1 disc diameter(DD) or larger was 43.4 +/- 30.6 mm/sec; the mean velocity in the feeder vessels of small CNV with greatest linear diameter smaller than 1DD was 20.3 +/- 20.2 mm/sec. There was a significant difference between them.
  
  
  CONCLUSIONS
  The flow velocity in feeder vessels of CNV could be measured with ICG angiography and a computer-based image analysis system. This system would be useful in evaluation of choroidal circulation.
authors.affiliation: Department of Ophthalmolmology, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamamoto
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D020256:Choroidal Neovascularization / Q000503:physiopathology*; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007208:Indocyanine Green; D007834:Lasers; D008268:Macular Degeneration / Q000150:complications; D008297:Male; D009887:Ophthalmoscopy / Q000379:methods*
chemical_list: D007208:Indocyanine Green