Bilberry was used by the RAF in WW2, and studies were done showing that it improved night vision. But my doc says they were very small samples and not definitive. On the other hand, there are not side effects, so worth a try. I tried for a year and didn't see any improvement.

Laser treatment is a 2-edged sword. It may halt degredation, but the process itself worsens the sight you do have. So depends on how fast the disease is progressing as to whether this is a reasonable option.