[An apparatus using laser speckle phenomenon for noninvasive 2-dimensional analysis of choroidal microcirculation].
A new instrument using the laser speckle phenomenon for noninvasive 2-dimensional analysis of the choroidal microcirculation was developed. The fundus was illuminated with a diode laser spot and its image speckle was detected with an area sensor. The difference between the average of the output data (I-mean) and the output data from successive scannings of the image speckles at the sensor plane was calculated and integrated to give as D-mean, and I-mean/D-mean was defined as normalized blur (NB), which is a quantitative index of blood flow velocity. The results were displayed in color graphics showing the 2-dimensional variation of the NB level in the area of interest. The NB had good correlation with the speed measured on ground glass in the range between 2 and 130mm/sec. Using this instrument, the effect of intraocular pressure on the chroidal circulation of the rabbit was studied. The coefficient of reproducibility was 6.9% when measured in the same area twice at 5-minute intervals. A stepwise reduction in the ocular perfusion pressure was introduced by elevating the intraocular pressure manometrically. A linear correlation was found between the NB and the ocular perfusion pressure.
Tamaki
Y
Y
Eye Clinic, Tokyo Metropolitan Geriatric Hospital, Itabashi-ku, Japan.
Kawamoto
E
E
Eguchi
S
S
Araie
M
M
Fujii
H
H
D000818:Animals; D001783:Blood Flow Velocity; D002829:Choroid / Q000098:blood supply*; D007429:Intraocular Pressure; D017078:Laser-Doppler Flowmetry / Q000295:instrumentation* / Q000379:methods; D008833:Microcirculation; D011817:Rabbits