Reproducibility of Perifoveal Fluorescent Dots Velocity Measurements on Fluorescein Angiography with a Scanning Laser Ophthalmoscope

ABSTRACT

To evaluate the reproducibility in measuring the velocities of perifoveal hyperfluorescent dots, we analyzed fluorescein angiographs of 24 eyes[24 patients]which had central serous retinopathy. Fluorescein angiography was performed with a scanning laser ophthalmoscope[SLO, Rodenstock, Mnchen, Germany]Distances between 5 moving hyperfluorescent dots in a perifoveal capillary were measured at each consecutive frame[interval 1/30 sec]. And then velocities of 5 fluorescent dots were measured with image analysis program by converting the distances to real retinal size using the Littmann's curve in 20 eyes. In the other 4 eyes, the velocities between 5 fluorescent dots of each 2 to 4 capillaries were measured. Perifoveal capillary mean blood flow velocity and standard deviation were 2.08 +/-0.36 mm/sec, and mean coefficient of variation of the velocities measured in a vessel of one patient was 12.58%. However, reliability of the velocities of 2 to 4 capillaries on the 4 eyes was relatively low. In conclusion, the measurement of velocities between perifoveal fluorescent dots with scanning laser ophthalmoscope may be a reproducible method for a perifoveal capillary. However, reliability of measuring velocities was not sufficient enough to use the velocity of one perifoveal capillary as macular blood flow.