[Color-coded Doppler sonography of orbital blood vessels with special reference to the central retinal artery and vein].

When certain conditions are met, parameters correlating with orbital and retinal perfusion can be investigated non-invasively with the use of Doppler ultrasonography. Color coding allows more rapid vessel localization and more precise definition of sample volume localization. Flow direction and blood velocity in the central retinal artery and vein, as well as in the ophthalmic artery, were evaluated under normal and pathological conditions using current B-scan Doppler instruments with color coding. Fourteen patients with central artery occlusion, 9 with central vein occlusion, and 9 with orbital arteriovenous fistulas were compared with a control group. In the patients with retinal venous prethrombosis and thrombosis, the blood velocities were not significantly decreased. Patients with retinal arterial occlusion had contradictory findings, presumably since recanalization had already taken place. Echographic flow imaging might be most useful when, particularly after treatment, flow velocity patterns in the orbital vessels are evaluated, and when angiographic procedures can be avoided. Illustrative cases such as spontaneous dura-cavernous sinus fistulas versus cavernous sinus thrombosis show that difficult diagnostic decisions can be made easier.