BLOOD-FLOW VELOCITIES IN THE EXTRAOCULAR VESSELS IN NORMAL VOLUNTEERS

PURPOSE: To determine normal values of bloodflow velocities in extraoc ular vessels. METHODS: In one eye each in 189 healthy adult volunteers , blood-flow velocities in the ophthalmic artery (OA), central retinal artery (CRA), central retinal vein (CRV), short lateral posterior cil iary artery (LPCA), and short medial posterior ciliary artery (MPCA) w ere measured by color Doppler imaging. In the arteries, peak systolic velocity (PSV), end diastolic velocity (EDV), and resistivity index (R I) were calculated. In the CRV, maximal and minimal blood-flow velocit ies were measured. Influence of age, gender, blood pressure, and heart rate on blood-flow velocities and the resistivity index were analyzed . RESULTS: Mean outcomes +/- S.D. cm/sec were as follows: in the OA, P SV was 39.2 +/- 5.3, EDV was 9.1 +/- 2.5, and RI was 0.77 +/- 0.05. In the CRA, PSV was 11.0 +/- 1.8, EDV was 3.3 +/- 0.9, and RI was 0.71 /- 0.05. In the short LPCA, PSV was 11.2 +/- 1.7, EDV was 3.7 +/- 1.0, and RI was 0.68 +/- 0.06, In the short MPCA, PSV was 11.2 +/- 11.7, E DV was 3.6 +/- 0.9, and RI was 0.68 +/- 0.05. In the CRV, mean maximal velocity was 4.5 +/- 0.9, and mean minimal velocity was 3.3 +/- 0.7. Age, gender, systolic blood pressure, diastolic blood pressure, and he art rate had no consistent statistically significant influence on the measured and calculated variables. CONCLUSION: Normal values for blood -flow velocities in the extraocular vessels serve as a basis in decidi ng whether a measured value of a patient is normal or abnormal.