Reproducibility of transcranial Doppler ultrasound examinations of the ophthalmic artery flow velocity.

Transcranial Doppler ultrasound measurements of ophthalmic artery velocity were made on 88 patients predominantly suffering from glaucoma. Of the four observed parameters, peak velocity, mean-enveloped velocity, diastolic velocity, and resistivity index, the latter was found to be the most reproducible (CV = 5.2%). The variability between patients was approximately twice that of the variability between consecutive measurements. Measurement error appeared to decrease as the operator gained experience.