Optical coherence tomography: a tool for predicting subclinical neurodegeneration in RRMS

Abstract Background Optic neuritis (ON), the cardinal visual affection in multiple sclerosis (MS), directly contributes to long-term disability. Optical coherence tomography (OCT) provides a quantifiable, sensitive biomarker to monitor the optic nerve affection and disease progression. Aim of the work To study the reliability of OCT in detecting subtle disease progression in patients with relapsing-remitting MS (RRMS). Patients and methods Twenty_ five Egyptian patients presented with RRMS were included, twenty_ five age, sex and educational level matched healthy volunteers were selected as a control group for comparison of Paced Auditory Serial Addition Test (PASAT ) and OCT data, the patients were subjected to neurological examination, assessment of disability, assessment of cognitive function, radiological assessment with Magnetic Resonance Imaging (MRI) brain and cervical spine and ophthalmology evaluation by OCT at baseline and reassessed 9 months later. Results MS patients showed worse performance in the PASAT score and lower OCT parameters than controls. The history of ON was associated with lower retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness and higher focal loss volume (FLV) and global loss volume (GLV). RNFL change rate had a statistically significant positive correlation with PASAT score and the annual relapse rate. A significant positive correlation was found between the rate of RNFL, GCC change and T1 black holes. Conclusions Retinal layers thinning was evident at early stages of RRMS and showed significant association with relapse rate, cognitive impairment and T1 black holes particularly in patients with ON highlighting the role of OCT as useful tool for early detection of neurodegeneration.