Retinal nerve fibre layer thickness correlates with brain white matter damage in multiple sclerosis
The aim of this study was to investigate the association of retinal nerve fibre layer thickness (RNFL) with white matter damage assessed by diffusion tensor imaging (DTI).
The authors recruited 44 patients with multiple sclerosis (MS): 12 without optic neuritis (ON) history, 14 with history of unilateral ON and 18 with history of bilateral ON. Neurological disability was assessed according to the Expanded Disability Status Scale (EDSS). A group of healthy controls (n = 30) received the same measurement protocol.
DTI data were acquired at 3T scanner. Optical coherence tomography (OCT) was performed with a Heidelberg Spectralis SD-OCT. DTI processing was performed with FMRIB Software Library (FSL). They restricted analysis to masks of the optic radiation (OR), the central corpus callosum and the remainder of the whole skeleton after excluding these two masks.
Tract-based spatial statistics (TBSS) analysis showed a significant positive correlation between nerve fibre layer thickness (RNFL) and fractional anisotropy (FA) and RD along the OR but also beyond that region. The correlation analysis between RNFL and DTI parameters inside the OR, central corpus callosum and whole skeleton (including and excluding these two regions) confirmed the TBSS results in MS patients. No correlation was found between RNFL and FA in the control group either in the TBSS or in the region-based analysis.
The results showed a significant correlation of retinal nerve fibre layer thickness with white matter tracts functionally separated from the visual system and a good correlation between retinal nerve fibre layer thickness and fractional anisotropy inside the optic optic radiation only in the patient group.
Scheel M, Finle C.
Mult Scler. 2014 May 19. pii: 1352458514535128. [Epub ahead of print]
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