Number of patients tested at entrance examination into the study and retested at annual follow-up intervals after entrance
| Entrance | 1-year follow-up | 2-year follow-up | 3-year follow-up | |
| Visual acuity | 23 | 18 | 14 | 11 |
| Retinal nerve fibre layer | 20 | 14 | 11 | 10 |
| DT-MRI optic radiation FA | 19 | 13 | 9 | 6 |
DT-MRI, diffusion tensor MRI; FA, fractional anisotropy.