Smaller optic nerve diameters and reduced flow velocity of ophthalmic artery suggest a history of optic neuritides: Transorbital Ultrasonography and Doppler Ultrasound in multiple sclerosis

Changes of the optic nerve (ON) reflect the overall pathology in multiple sclerosis (MS). We preliminarily explored morphological and haemodynamic changes in a sample of MS patients with Transorbital Ultrasonography (TOUS) and Doppler Ultrasound (DUS). 85 MS patients, 65 women and 20 men aged 43.6 (12.1) and 45.0 (14.6) (p = ns) years, were enrolled. EDSS score was 0–2.5 in 55 (64.7%) and > 2.5 in 30 (35.3%) subjects. Morphometric (ON diameters) and haemodynamic (from ophthalmic artery, OA, central retinal artery, CRA, posterior ciliary arteries, PCA) features were computed for affected (AE) vs. non affected (nAE) eyes. ANCOVA was used to control for sex, age, number of optic neuritides (ONt). A history of ONt (hONt) was detected in 48 (28,2%) patients, 8 (16,7%) men and 40 (83,3%) women. HONt was associated with lower EDSS scores (75% with EDSS 0–2.5 vs. 25% >2.5). 160 eyes were studied, 53 (33.1%) with hONt. AE was associated with younger mean (SD) age (40.3 (10.5) vs. 44.6 (13.3) years). ON diameter at 3 mm, and ON sheath diameters at 3 and 5 mm from papilla were smaller in AE (Mann-Whitney U, p = 0.013, p = 0.033, and p = 0.026, respectively). No differences were observed for the myelination index ratio. Marginal means of flow velocities were lower for OA in AE vs. nAE (ANCOVA, p = 0.011), but not for CRA and PCA. In MS patients, smaller ON diameters and a reduced flow velocity in OA detected with TOUS and DUS may suggest hONt.