(Concern) Worry about macular degeneration and cataracts

My mother was diagnosed with macular degeneration in one eye, so her vision is poor. I think she is almost legally blind in that eye. The hospital said it was too late to treat and nothing could be done. So, she has been only taking eye supplements recommended to prevent further deterioration. She also had cataract surgery on the other eye. I am worried that her other eye might also worsen. Is there a good way to prevent her eyes from getting worse?