Retinal nerve fibre layer thickness associates with cognitive impairment and physical disability in multiple sclerosis

Abstract

PurposeReductions in the retinal nerve fibre layer (RNFL) have been indicated even in early‐stages of multiple sclerosis (MS). The aim was to assess the potential of the RNFL quadrant measurements in differentiating disease phenotypes and their association with cognitive impairment and physical disability.MethodsFour hundred and sixty‐five MS patients and 168 healthy controls (HCs) were included. MS subjects were divided in subgroups according to disease phenotype. All subjects underwent optical coherence tomography (OCT) examination of all retinal quadrants using Canon OCT HS‐100. Associations were tested using linear mixed effect models.ResultsThe global RNFL thickness was 6.4 μm thinner (95% CI: −8.5 to −4.3, p < 0.001) in relapsing‐remitting MS (RRMS), 11.6 μm thinner (95% CI: −14.4 to −8.8 μm, p < 0.001) in secondary progressive MS (SPMS) and 10.7 μm thinner (95% CI: −16.0 to −5.5, p < 0.001) in primary progressive MS (PPMS) compared with HCs. Global RNFL and temporal quadrant showed high correlation to cognitive impairment and physical disability in MS.ConclusionsWe report that RNFL thickness reduction is significantly associated with physical and cognitive disability and OCT measurements are useful for axonal loss. We suggest the use of temporal quadrant RNFL thickness as a more sensitive outcome as oppose to the global RNFL thickness.