A composite MRI and OCT based measure to explore the visual pathways in primary-progressive Multiple Sclerosis (P6.405)

Objective: To develop a composite MRI and OCT-based measure to investigate visual pathway damage in primary-progressive Multiple Sclerosis (PPMS) patients and determine if it explains visual disability better that the single measure. Background: Optical coherence tomography and non-conventional magnetic resonance techniques have demonstrated to be good tools in order to investigate visual pathways in Multiple Sclerosis (MS) and to study its underlying neurodegenerative process. However, it remains to be determined whether any composite score of these metrics could better explain visual disability when compared to a single parameter. Design/Methods: We enrolled twenty-six primary progressive patients and twenty age-matched controls that underwent a neuro-ophthalmologic evaluation, spectral-domain optical coherence tomography, and 3T brain MRI (optic nerve and tract diameters, optic radiation, thalamic and visual cortex volume, lesion volume within optic radiation and occipital and whole cortex, fractional anisotrophy in normal appearing white matter and within white matter lesions). Differences between groups were assessed by univariate general linear model and principal component analysis was used to group instrumental variables into main components. Results: Two principal components were identified and they followed an anatomical distribution, distinguishing variables into anterior visual pathways (first component) and posterior structures (second component). Correlations between visual acuity and each instrumental parameter showed that just ganglion cell-inner plexiform layers, optic radiation white matter lesions volume and fractional anisotrophy were significantly correlated to visual acuity. Global score calculated for each component significantly correlate (p 2 0.211, and 0.198 in the first and second component respectively). Conclusions: Our results provided evidences that a multiparametric score, based on OCT and MRI measures, provides a more comprehensive is able to better explain visual disability rather than a single instrumental metric. Disclosure: Dr. Poretto has nothing to disclose. Dr. Petracca has nothing to disclose. Dr. Saiote has nothing to disclose. Dr. Mormina has nothing to disclose. Dr. Howard has nothing to disclose. Dr. Paolo Gallo has received compensations from Biogen Idec, Novartis, Merk Serono, Bayer Schering and Genzyme for speaking and consulting activities.,,,,,, Dr. Miller has received personal compensation for activities with Accordant Health Services, Acorda, Alkermes, Biogen, EMD Serono, Genentech, , Novartis, Roche, and Sanofi-Genzyme,. Dr. Miller has received personal compensation in an editorial capacity for Continuum Audio. Dr. Miller has received research support from Biogen, Genentech/Roche, Sanofi Genzyme, Novartis, and Mallinckrodt. Dr. Lubin has received personal compensation for activities with Abbott, Acorda, Actelion, Allozyne, Avanir, Bayer HealthCare, Biogen Idec, Celgene, EMD Serono, Genmab, Johnson & Johnson, Medicinova, MorphoSys, Novartis, Pfizer, Questcor, Roche, Sanofi and Teva Neuros for consulting or serving on an advisory board. Dr. Inglese has received research support from Novartis Pharmaceuticals and Teva Neuroscience.