[The variability of blood velocity in the ophthalmic artery with color Doppler imaging].

ABSTRACT

Non-invasive measurements of blood velocities of the ophthalmic artery (BVA) in color Doppler imaging (CDI) are increasingly used to assess the influence of disease on the hemodynamics of the eye. Such measurements are only valid when compared to spontaneous variability. Therefore, the aim of this study was to examine the variability of BVA in healthy subjects. Within-a-day short-term variability was assessed from measurements obtained during one day from 5 healthy young male subjects as the coefficient of variation (CV) of 10 consecutive measurements. Between-days variability was assessed by comparing measurements made on three different days at one month intervals. The left and right BVA were measured five consecutive times to evaluate the difference in BVA between left and right eyes in 5 healthy young male subjects. In the within-a-day variability, mean CV in maximum systolic BVA (V max), minimum end diastolic BVA (V min), time-averaged BVA (V mean), resistive index (RI), and pulsatility index (PI) were found to be 6.6%, 14.0%, 14.9%, 3.2%, and 17.4%, respectively. The between-days variability was just as high as the within-a-day variability. There was significant difference in BVA between left and right eyes in two of the five subjects. We concluded that the within-a-day variability and the between-days variability of BVA measured using CDI are reproducible. The CDI can be used to assess the influence of disease and drugs on the hemodynamics of the eye.