[Color Doppler echography of the orbit. Its normal aspects and pathological conditions with vascular involvement]

This study was aimed at investigating the role of color-Doppler US in the assessment of orbital vasculature under normal conditions; the results were then applied to the flowmetric analysis of some vascular diseases of the orbit, i.e., retinitis pigmentosa, simple chronic glaucoma, low-tension glaucoma and carotid-cavernous fistulas. The study consisted of two phases: first, a group of 20 healthy volunteers was examined and then 39 patients were divided into 4 subgroups. The patients (18 men and 21 women, age range: 52-68 years) were further divided into 4 subgroups: 12 of them had retinitis pigmentosa, 15 simple chronic glaucoma, 8 low-tension glaucoma and 4 carotid-cavernous fistulas. Color-Doppler yielded useful pieces of information on the position of orbital vessels and flow direction, while pulsed Doppler allowed the measurement of several variables, i.e., time average velocity, protosystolic velocity, peak systolic velocity, mesodiastolic velocity, end diastolic velocity, resistive index and pulsatility index. The study of the 20 healthy volunteers yielded valuable information on the anatomy and flow patterns of some vessels, such as the ophthalmic artery, the central retinal artery, the lacrimal artery and the posterior ciliary arteries, all of them visible in 90-100% of patients; the central retinal vein, the superior ophthalmic vein and venae varicosae were demonstrated in about 10-30% of them. In the group of patients, the mean flow velocities of the examined arteries were significantly lower than those in the normal volunteers; in the patients with carotid-cavernous fistulas an ectasic superior ophthalmic vein was demonstrated, with its typical flow "arterialization" pattern. The results suggest that color-Doppler could play a mayor role in the study of ocular hemodynamics.