Analysis of macular and nerve fiber layer thickness in multiple sclerosis patients according to severity level and optic neuritis episodes

Introduction: Quantitative assessment of macular and nerve fibre layer thickness in multiple sclerosis patients with regard to expanded disability status scale (EDSS) and presence or absence of previous optic neuritis episodes. Methods: We recruited 62 patients with multiple sclerosis (53 relapsing-remitting and 9 secondary progressive) and 12 disease-free controls. All patients underwent an ophthalmological examination, including quantitative analysis of the nerve fibre layer and macular thickness using optical coherence tomography. Patients were classified according to EDSS as A (lower than 1.5), B (between 1.5 and 3.5), and C (above 3.5). Results: Mean nerve fibre layer thickness in control, A, B, and C groups was 103.35 +/- 12.62, 99.04 +/- 14.35, 93.59 +/- 15.41, and 87.36 +/- 18.75 mu m respectively, with statistically significant differences (P<.05). In patients with no history of optic neuritis, history of episodes in the last 3 to 6 months, or history longer than 6 months, mean nerve fibre layer thickness was 99.25 +/- 13.71, 93.92 +/- 13.30 and 80.07 +/- 15.91 mu m respectively; differences were significant (P<.05). Mean macular thickness in control, A, B, and C groups was 220.01 +/- 12.07, 217.78 +/- 20.02, 217.68 +/- 20.77, and 219.04 +/- 24.26 mu m respectively. Differences were not statistically significant. Conclusions: The mean retinal nerve fibre layer thickness in multiple sclerosis patients is related to the EDSS level. Patients with previous optic neuritis episodes have a thinner retinal nerve fibre layer than patients with no history of these episodes. Mean macular thickness is not correlated to EDSS level. (C) 2014 Sociedad Espanola de Neurologia. Published by Elsevier Espana, S.L.U. All rights reserved.