Background: Optic Neuritis occurs in about 20% of MS patients as the initial symptom.
To assess the clinical utility of optical coherence tomography (OCT) to measure axonal degeneration of the optic nerve, using retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) analyses, in a cohort of subjects meeting the diagnostic criteria of multiple sclerosis (MS).
Methods: We analyzed the baseline and 6-month follow up data for 73 MS patients in the study. Data was abstracted from clinical research source documents. The main outcome measures were expanded disability status scale (EDSS), National Eye Institute Visual Function Questionnaire (NEIFVQ), OCT: GCL and RNFL. Demographic and clinical characteristics were also reported. Descriptive statistics and point biserial correlations were calculated using Statistical Package for the Social Sciences Version 26.
Most subjects were female (76.7%) and Caucasian (89.0%). The mean age was 54.7 years. Eighty-one percent (80.8%) had an MS type of RRMS and 38.4% had optic neuritis (ON) in at least one eye. Mean RNFL thickness of the MS cohort, stratified by age and ethnicity was thinner compared to published age matched normative database.
There was no statistically significant relationship between EDSS score and optic neuritis.
There was no significant relationship between EDSS and GCL thickness or RNFL thickness at either baseline or 6 months.
There was a significant correlation between subjects diagnosed with ON and NEIVFQ, r(71) = -.269, p=.022.
There was no significant relationship between NEIVFQ scores and RNFL thickness.
There was a significant moderate correlation between subjects diagnosed with ON and baseline RNFL thickness, r(68) = -.476, p<.01. For subjects diagnosed with ON, there was a significant moderate correlation between RNFL 6-month scores and OCT 6-month scores, r(17) = -.476, p=.039. Conclusions: Our data confirms previously published findings, confirming the presence of RNFL thinning in patients with MS. It also confirms that patients with a history of ON showed more pronounced thinning compared to MS patients with no history of ON. The utility of OCT to assess patients with MS needs to be analyzed in the context of ON versus no ON. Designing optimal tools for measuring MS progression and developing appropriate biomarkers for clinical trials will require collaborative work with Ophthalmology and Neurology. Our data supports the potential utility of OCT in a multispecialty clinic setting, in this regard.