1Department of Ophthalmology, St. Marianna University School of Medicine, 2Department of Laboratory Medicine, St. Marianna University School of Medicine, 3Department of Ophthalmology, Nissan Tamagawa Hospital
Purpose: Direction of blood flow in the ophthalmic artery observed using the Doppler method in ocular diseases and in relation to occlusive carotid artery diseases has been discussed by many researchers in various departments. Underlying problems are discussed from the fact that any type of flow pattern, even reversal, may be obtained simply by changing the angle of the probe. Subjects and Methods: Pulsed Doppler waves were recorded in the orbital ophthalmic arteries of healthy individuals under prospectively obtained informed consent. An SSA-700A (Toshiba) ultrasound unit equipped with a 7.5 MHz linear probe was used. Color Doppler images were acquired in the supine position through a closed eyelid while gazing straight ahead with the collateral eye and contact methods employing hydroxyethyl cellulose ophthalmic solution as an acoustic coupler. Pulsed Doppler images were recorded while slightly changing the angle of the probe pointing at the targeted position. Results and Discussion: Forward, backward, and bidirectional waves were recorded from the same part of the orbital ophthalmic artery of the same person while varying the angle of the probe. Various pulsed Doppler wave forms were detected from the same examinee. The intraorbital course in the ophthalmic artery is known to retain rich anatomical variations. A detailed description of probe-positioning is an absolute requirement when considering direction of flow and the flow pattern of the ophthalmic artery. We think that examinations of velocimetry in the ophthalmic artery need to be conducted, so as to minimize the angle between the underlying direction of blood flow and the ultrasound beam, which is reproducible in measuring more than three times. Conclusion: This study suggests that forward, backward, and bidirectional pulsed Doppler waves may be obtained by simply changing the angle of the Doppler beam and the ophthalmic artery.