Figure 1

Models of the change in retinal layer thicknesses and brain volume during MS course. The black points joined by dashed lines represent the individual trajectories of the changes in retinal thickness (per eye) or brain volume (per subject), while the thicker curves represent the individual fit of the model (per eye for the retinal model and per subject for the brain volumes) and the dark red line represents the population model. (A) Peripapillary retinal nerve fiber layer (pRNFL); (B) ganglion cells plus inner plexiform layer (GCIPL); (C) whole brain volume; (D) gray matter volume; and (E) thalamus volume. The Y axis represents the relative change ([visit minus baseline]/baseline) in the eye or brain region. The X axis represents the time (years) from clinical onset. All models are linear spline mixed-effects models following the equation: \(\widehat{y } \sim lspline\left(disease duration, knot=5\right)+(1\left|participant+1\right|eye:participant)\) for the retina, and \(\widehat{y } \sim lspline\left(disease duration, knot=5\right)+(1|participant)\) for the brain. All the models were fitted using the “lme4” package for R.