[Color Doppler Imaging of the orbital vessels]

In ophthalmologic ultrasonography, Color Doppler Imaging (CDI) is a valuable method for detecting hemodynamic information in the central vessels of the retrobulb (ophthalmic artery, central retinal artery and internal carotid artery, etc.) and complementing the diagnosis of eye and eyeground view. Especially in diabetics, if orbital peripheral vascular resistance goes up with progress of diabetic retinopathy, the ophthalmic artery flow velocity wave form undergoes remarkable change, and the ratio of systolic mean velocity to diastolic mean velocity (mean S/D ratio) increases. On the other hand, if carotid obstruction and carotid advanced stenosis arise in sphagitides by the progress of macroangiopathy, the ophthalmic artery becomes the collateral pathway. Then, the flow directional reversal responsible for the collateral pathway is recognized and enters cerebral circulation and, as a result, the ophthalmic artery causes a fall in retinal circulation. As mentioned above, CDI in the ophthalmologic field plays a useful role not only in eyeground management, but in elucidation of the mechanism of ocular ischemic syndrome.