## 5 Results
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Average Annual Rate (SEM)** & \(p\)**-Value** \\ \hline
**TMV (mm\({}^{3}\))** & \(-0.1\) (0.01) & **<0.001** \\
**CRT (\(\upmu\)m)** & \(-1.81\) (0.41) & **<0.001** \\
**pRNFL-T (\(\upmu\)m)** & \(-3.3\) (0.51) & **<0.001** \\
**_Superior quadrant (\(\upmu\)m)_** & \(-2.67\) (0.37) & **<0.001** \\ _Nasal quadrant (\(\upmu\)m)_ & \(-1.19\) (0.36) & **0.001** \\ _Inferior quadrant (\(\upmu\)m)_ & \(-2.31\) (0.39) & **<0.001** \\ _Temporal quadrant (\(\upmu\)m)_ & \(-0.78\) (0.28) & **0.005** \\
**NRR-T (\(\upmu\)m)** & \(-12.79\) (5.57) & **0.021** \\ \hline \hline \end{tabular}  
* Values in bold indicate significant change (\(p\) values \(<0.05\)).  
\end{table} 
Table 3: Longitudinal analysis of the OCT parameters in RR-MS patients. In particular, we found more evident differences in relation to the pRNFL-T, which decreased at a mean rate of \(-3.5\pm 0.55\) um/year in ON+ patients (\(p=0.001\)), while in ON- patients the change was not statistically significant, being \(-0.54\pm 1.39\) um/year (\(p=0.696\)). Similarly, as summarized in Table 4, we observed a significant reduction in RNFL-T in the superior and inferior quadrants of approximately 3 um/year in ON+ patients (\(p<0.001\)), while the changes during the follow-up were not statistically significant in ON- patients (\(p=0.339\); \(p=0.431\), respectively). Finally, the ON+ patients showed statistically significant progression in the average annual rate of the NRR-T of \(-36.59\pm 2.74\) um (\(p<0.001\)), compared with the ON- patients, who instead showed a reduction rate that was not statistically significant of \(-3.26\pm 8.44\) um/year (\(p=0.699\)) (Table 4). Figure 1: RNFL longitudinal analysis in a selected multiple sclerosis (MS) ON– patient. Figure 1 shows no significant changes in retinal nerve fiber layer thickness (RNFL-T) at various time points in a selected MS ON– patient. In fact, in the colorimetric maps related to the RNFL-T in the peripapillary quadrants (S = superior; N = nasal; I = inferior; T = temporal), performed both 1 year and 2 years after the study baseline, a shift towards warmer colors (e.g., red), which is indicative of a significant thinning of the RNFL, is not observed. Figure 2: RNFL longitudinal analysis in a selected MS ON+ patient. Figure 2 shows progressive and significant RNFL thinning during the follow-up in a selected MS ON+ patient. In fact, in the right eye colorimetric map, a significant thinning of the RNFL in the superior peripapillary quadrant is observed, as indicated by the color change toward red, which is appreciable both 1 year and 2 years after the baseline. Similarly, in the left eye, the RNFL-T significantly decreases (turns red) in the temporal peripapillary quadrant at 2 years. Regarding the EDSS and visual parameters, we did not find significant differences between the two subgroups. Instead, relative to the VF-MD, ON+ patients showed a significant reduction of \(-0.58\pm 0.24\) dB/year, whereas the ON\(-\) patients showed a significant increase of \(+0.35\pm 0.08\) dB/year, and the difference between the two groups was statistically significant (\(p<0.001\)).