Ocular Coherence Tomography Macular Volume Predicts Walking Speed in Patients with Multiple Sclerosis (P6.305)

Objective: To correlate retinal thickness with walking speed in patients with multiple sclerosis (MS) or clinically isolated syndrome (CIS). Background: Optical coherence tomography (OCT) is a technique using near-infrared light to examine and measure the thickness of the layers of the retina. It is used in patients with MS to objectively quantify the effects of optic neuritis, monitor disease progression, and assess for disease modifying therapy side effects. Methods: This was a retrospective, observational study of patients diagnosed with MS or CIS. A clinic database and electronic medical record were used to identify patients with an OCT, timed 25 foot walk, and visual acuity performed within 3 months. The Spearman correlation matrix was computed among the variables, including OCT findings (retinal nerve fiber layer thickness, ganglion cell and inner plexiform layer thickness, and macular volume), visual acuity, timed 25 foot walk, and age. A univariate analysis identified statistically significant variables to evaluate the overall significance of each variable. A multivariate analysis was then performed to determine significance. Results: Four hundred thirty-one patients met inclusion criteria. The univariate analysis identified a statistically significant correlation between 25 foot walk and the following variables: age, best/worst visual acuity, best/worst corrected macular volume, best corrected ganglion cell layer, and best/worst corrected retinal nerve fiber layer thickness. The multivariate analysis identified age and best corrected macular volume to be significant predictors of walking speed. The walking speed increased 0.876 ft/s with every one unit increase in macular volume. Conclusions: This was a unique study to correlate findings on OCT with walking speed in patients with MS or CIS. It indicated that degeneration of the retina (particularly macular volume) in MS/CIS predicted slower walking speed. Disclosure: Dr. Seay has nothing to disclose. Dr. Fan has nothing to disclose. Dr. Bermel has received personal compensation for activities with Biogen Idec., Novartis, Teva, Genzyme and Questcor.