Abstract
Purpose: :
To evaluate whether the hemodynamics of the retinal vein can be measured by an invasive device, a laser speckle flowgraph (LSFG-NAVI, Softcare, Ltd., Japan), in cases with branch retinal vein occlusion (BRVO).
Methods: :
Fourteen patients with untreated BRVO were analyzed. A retinal blood flow pattern was recorded by laser speckle measurement using the LSFG-NAVI. A skewed value in the LSFG-NAVI recording represents a gap in the blood flow distribution curve. The alternating current (AC) represents the range of the blood flow distribution curve and the direct current (DC) represents the mean value of this curve in the LSFG-NAVI measurement. The LSFG-NAVI selected three areas as measurement points, then calculated the skew value and AC/DC value at each point in each eye. The first point was a main upper temporal branch retinal vein, the second point was a main lower temporal branch retinal vein, and the third point was a disc area.
Results: :
There were no significant differences in the mean skew values between the right and left eyes or between the upper and lower temporal veins, in all of the eyes examined. In eyes with BRVO, the mean AC/DC values were 0.39 in non-occluded veins and 0.52 in occluded veins (p=.0062).
Conclusions: :
The skew value, an index of vascular stiffness, did not differ significantly between BRVO eyes and fellow eyes. However, the AC/DC value, an index of changes of blood flow volume, differed significantly from the occluded vein to the non-occluded vein. These results suggest that the measurement of retinal blood flow with the LSFG-NAVI may help to prove the broken homeostasis of blood flow volume in the occluded veins of BRVO eyes.
Keywords: retina • blood supply