Peripapillary retinal nerve fibre layer thinning rate as a biomarker discriminating stable and progressing relapsing–remitting multiple sclerosis

Background and purpose Peripapillary retinal nerve fibre layer (pRNFL) thickness is a strong candidate as a biomarker of axonal degeneration in multiple sclerosis (MS). The aim was to determine a cut‐off value of pRNFL thinning rates in relapsing–remitting MS (RRMS) to discriminate between stable and progressing patients. Methods In this 3‐year prospective longitudinal study on 141 RRMS patients, annual pRNFL thinning rates (aLpRNFL) were determined by individual linear regression models. The best possible cut‐off value discriminating clinically progressing (physical progression or cognitive decline) and stable patients was defined by receiver operating characteristic analysis. Cut‐off values were validated using a multivariate logistic regression model. Results Average aLpRNFL in progressing patients (2.4 μm, SD 2.1) was significantly higher compared to stable patients (0.5 μm, SD 1.2, P 1.5 μm was able to distinguish between stable and progressing RRMS with a sensitivity of 76.1%. aLpRNFL >1.5 μm was associated with a 15‐fold increased risk of clinically progressing MS (P