A fluorescent vesicle system for the measurement of blood velocity in the choroidal vessels.
OBJECTIVE
Evaluation of the pathophysiologic mechanisms involved in the choroidal circulation is difficult because of the presence of the retinal pigment epithelium. The authors have developed a technique for measuring blood velocity in individual choroidal vessels using the scanning laser ophthalmoscope and intravenously injected indocyanine green encapsulated in multilamellar vesicles. In this report, the authors describe their attempts to measure choroidal blood velocity in three different regions of the choroid of the primate eye.


METHODS
A video-to-digital processor was used to digitize the video images of the choroid of a monkey at a sample rate of 1/30 of a second. The blood velocity in the selected choroidal vessel segments was calculated by measuring the distance the liposome traveled in a given time.


RESULTS
The average blood velocities were 5.16 mm/s under the macula, 4.04 mm/s in the vortex vein system, and 2.03 mm/s in the choroidal circulation nasal to the optic nerve.


CONCLUSIONS
This technique is an effective method of measuring blood velocity in a primate model and has several important advantages compared with the dye dilution technique.
Peyman
G A
GA
LSU Eye Center, Louisiana State University Medical Center School of Medicine, New Orleans 70112-2234, USA.
Khoobehi
B
B
Shaibani
S
S
Shamsnia
S
S
Ribeiro
I
I
D000818:Animals; D001783:Blood Flow Velocity; D002829:Choroid / Q000098:blood supply* / Q000502:physiology*; D004396:Coloring Agents; D007091:Image Processing, Computer-Assisted; D007208:Indocyanine Green; D007834:Lasers; D008081:Liposomes; D008253:Macaca mulatta; D019721:Ophthalmoscopes; D010857:Pigment Epithelium of Eye / Q000166:cytology
D004396:Coloring Agents; D008081:Liposomes; D007208:Indocyanine Green