Magnetic resonance imaging and optical coherence tomography correlations in multiple sclerosis beyond anatomical landmarks.

Abstract Objective To investigate multiple sclerosis (MS) optical coherence tomography (OCT) cross-sectional correlations with central nervous system (CNS) magnetic resonance imaging (MRI). Material and methods Peripapillary retinal nerve fiber layer (pRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner (INL) and outer nuclear layer (ONL) of 54 relapsing remitting (RRMS) and 38 progressive (PMS, 9 primary and 29 secondary) patients were measured. With less than 3 months brain parenchymal fraction (BPF), spinal cord (SC), total gray matter (GM) and white matter volumes were calculated. Demographical and clinical data was compared according to the history of optic neuritis (HON). Relationships between OCT and MRI data were assessed using multivariable linear regression models, adjusting for age, gender and disease duration, taking into account HON and disease subtype. Results Cerebellum (p = 0.008), pRNFL (p = 0.001), GCL (p = 0.001) and IPL (p = 0.001) were thinner, while INL was thicker (p = 0.02) if HON. SC correlated better with nasal pRNFL sectors in eyes with HON (all eyes: average pRNFL p = 0.035 η2 = 0.213; N-pRNFL p = 0.04 η2 = 0.36, NI-pRNFL p = 0.0001 η2 = 0.484. RRMS eyes: N-pRNFL p = 0.034 η2 = 0.348; NI-pRNFL p = 0.013 η2 = 0.441), while it correlates with PMB (p = 0.032 η2 = 0.144), GCL (p = 0.03 η2 = 0.147) and IPL (p = 0.028 η2 = 0.151) in eyes without HON regardless of the disease subtype. INL presented no microcystic macular oedema and was inversely associated with BPF (p = 0.029 η2 = 0.363) and cerebellum (p = 0.015 η2 = 0.428) in PMS eyes without HON. Conclusions OCT data correlates with different CNS compartments, even with no anatomical or functional linkage, serving as useful neurodegeneration and inflammation surrogate marker.