Retinal Thickness as a Potential Biomarker of Neurodegeneration and Early Cognitive Impairment in Patients With Multiple Sclerosis

The degree of physical disability was assessed by using the Expanded Disability Status Scale (EDSS). The EDSS score ranges from 0 to 10 in 0.5 unit increments that represent higher levels of disability. Neurocognitive functions were evaluated using the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) that includes the following tests: 1. Symbol Digit Modalities Test (SDMT) that is used for assessment of information processing speed. 2. California Verbal Learning Test - 2nd edition (CVLT-II) . 3. Brief Visuospatial Memory Test-Revised (BVMT-R) OCT assessment was performed by spectral domain-optical coherence tomography to assess the retinal nerve fiber layer thickness and macular volume in humans . Each eye for every patient was assessed by measuring the thickness of RNFL and GCC, respecting presence or absence of the previous history of optic neuritis (ON).