COLOR DOPPLER IMAGING OF ORBITAL VENOUS FLOW IN DYSTHYROID OPTIC NEUROPATHY

Color Doppler imaging was performed to evaluate the venous stasis in 3 9 orbits, including 9 optic neuropathy orbits, of 20 patients with dys thyroid ophthalmopathy and 22 orbits of 11 healthy subjects. The super ior ophthalmic vein (SOV) was detected in 26 dysthyroid ophthalmopathy orbits and in 13 control orbits. The blood flow in the SOV was in the anteroposterior direction in 20 dysthyroid ophthalmopathy orbits and in 13 control orbits. Reversed how, ie, the flow in the posteroanterio r direction, was seen in 6 dysthyroid ophthalmopathy orbits and in non e of the control orbits. In dysthyroid ophthalmopathy orbits, the bloo d flow in the SOV was reversed in 5 (36%) of the 14 orbits with apical orbital crowding observed on computed tomography, which means there w as compression of the optic nerve by enlarged extraocular muscles, as compared to in 1 (4%) of the 25 orbits without apical orbital crowding (P<0.05). The percentage of the orbits having reversed flow in SOV wa s 44% of dysthyroid ophthalmopathy orbits with optic neuropathy as opp osed to 7% of those without optic neuropathy (P<0.05). Reversed blood flow in the SOV strongly supported the existence of severe venous stas is in the orbits, which may be related to the development of dysthyroi d optic neuropathy.