The Role of Vitamin D in Optic Neuritis - An Update (P6.147)

OBJECTIVE: We hypothesize that vitamin D sufficiency (25(OH)D > 80 nmol/L) is associated with better optical coherence tomography (OCT) outcomes and axonal preservation/recovery after optic neuritis (ON). Outcomes include retinal nerve fiber layer (RNFL) thickness, ganglion cell layer (GCL) thickness and inter-eye difference (IED) in both at 6 months and baseline between vitamin D sufficient and insufficient groups. BACKGROUND: Optic neuritis is a common manifestation of demyelinating disease. The optic nerve can serve as a model of the central nervous system, allowing for evaluation of inflammation and degeneration using OCT to measure RNFL thickness and other afferent visual pathway markers. Vitamin D insufficiency is a risk factor for multiple sclerosis and ameliorates inflammation. Assessment of vitamin D status in ON may support a neuroprotective role as well. DESIGN/METHODS: In this prospective cohort study, patients with acute ON undergo OCT to assess RNFL, GCL, macular volume (MV) and serum 25(OH)D levels at baseline and month 6. RESULTS: Presently, of 49 patients enrolled (36F/13M), 68% were vitamin D insufficient at baseline, which was associated with greater baseline edema in RNFL (131 vs 106 µm, p=0.14) and MV (10.2 vs 9.8 mm 3 , p=0.036). At month 6, while RNFL edema persisted, GCL IED was greater in insufficient patients (13 vs 8 µm). Regardless of baseline RNFL or vitamin D level, men had significantly lower 6 month RNFL (70 vs 81 µm, p=0.028) and greater IED in RNFL and GCL (20 vs 8 µm for both, p=0.012 and p=0.008 respectively) versus women. CONCLUSIONS: Vitamin D insufficiency at ON onset is associated with greater edema, supporting its known anti-inflammtory role. We have also shown that male gender is an independent risk factor for poorer OCT outcomes at 6 months. Despite residual edema at 6 months, GCL data suggests vitamin D and female gender may confer neuroprotection and/or improved recovery in the optic nerve after ON. Study Supported by: University of Calgary, endMS Disclosure: Dr. Burton has received personal compensation in an editorial capacity for Teva Neuroscience, Novartis, Biogen Idec and EMD Serono. Dr. Trufyn has nothing to disclose. Dr. Tung has nothing to disclose. Dr. Eliasziw has nothing to disclose. Dr. Costello has received personal compensation for activities with Questcor and EMD Serono.