Association of 25-hydroxyvitamin D levels with RNFL thickness and clinical tests of visual function in acute optic neuritis (P1.338)

OBJECTIVE: To determine association between 25-hydroxyvitamin D (25HVITD) levels and 1) clinical tests of severity of acute optic neuritis (ON) and 2) optical coherence tomography (OCT) measurements of retinal nerve fibre layer thickness (RNFLT) in acute ON. BACKGROUND: Vitamin D levels have in some studies been linked with ON severity and may play a role in demyelination/remyelination during and following ON episodes. DESIGN/METHODS: A cross-sectional study of mean 25HVITD levels and clinical tests of visual acuity( Early Treatment of Diabetic Retinopathy Study (ETDRS)), color vision (Velhagen pseudoisochromatic plates and Lanthony desaturated 15-hue test), contrast vision(low contrast Sloan letters (lcSl) (1.25[percnt] and 5[percnt])) and OCT RNFLT measurements obtained in acute ON patients (within 4 weeks of onset). 165 patients consecutively referred ON patients from a geographically well defined area of Eastern Denmark between September 2009 and April 2014 were included. 25HVITD deficiency was defined at 50 nmol/L. 25HVITD levels were deseasonalized before analysis. Association between visual tests and 25HVITD was assessed by Spearman analysis and difference in median RNFLT in ON and fellow, non afflicted eye between vitamin D deficient and non-deficient groups was assessed by Mann-Whitney U-test. RESULTS: A non-significant trend towards worse ETDRS (r:-0.167, p:0.068) and contrast vision (1.25[percnt]lcSl(r:-0.119, p:0.195) 5[percnt]lcSl(r:-0.170, p:0.063)) as well as having more errors on Velhagen test (r:0.149, p:0.102) with increasing 25HVITD levels was found. No association was found for Lanthony’s test (p:0.778). No significant difference in RNFLT in ON eye or fellow non-afflicted eye was found between groups (p:0.707 and 0.860 ). CONCLUSIONS: The present study does not support a previous finding of association between serum vitamin D levels and tests of severity of ON. Rather a non-significant trend towards decreased color vision, contrast vision and visual acuity is indicated with increasing vitamin D levels. No difference in RNFLT was shown between vitamin D deficient and non-deficient ON patients. Disclosure: Dr. Pihl-Jensen has nothing to disclose. Dr. Frederiksen Battisti has nothing to disclose.