Assessment of the optic nerve and its arterial supply by ultrasound imaging in multiple sclerosis patients

Background Transorbital sonography (TOS) has emerged as a promising assessment tool of the optic nerve and orbital arterial supply in multiple sclerosis (MS) patients. Objective To evaluate optic nerve diameter (OND), optic nerve sheath diameter (ONSD), and orbital hemodynamics using TOS in MS patients. Methods Forty MS patients and 28 matched healthy controls were included. Thirty-three eyes with previous optic neuritis (ON) and 47 eyes without previous ON of MS patients were examined. All subjects were submitted to assessment of OND, ONSD, and parameters of orbital hemodynamics using orbital ultrasound. Results OND and ONSD were smaller in MS eyes with previous ON than in controls. MS eyes with and without previous ON had statistically significant higher peak systolic and mean velocity of posterior ciliary arteries than the control eyes. Orbital blood flow velocities were negatively correlated with the duration of disease and Expanded Disability Status Scale (EDSS). A statistically significant decrease in blood flow velocities of the central retinal artery was detected in secondary progressive MS (SPMS) patients than in relapsing-remitting MS patients (RRMS). Conclusion TOS can be used as a feasible tool to detect optic atrophy in MS patients. MS patients may have abnormal retrobulbar hemodynamics compared to healthy controls.