Stem cells have a new and futuristic sound and is "cutting edge" according to the proponents.
https://www.livescience.com/58287-unproven-stem-cell-therapy-blindness.html
They try stem cells on many parts of the body. First off, find a real medical doctor specialist in the field, and see what his treatment options are.
Be very very careful with going to some clinic and a guy in a white coat.
Talk to a real doctor with a practice in a real building like a hospital. And the part of the body being treated makes a big difference. Check out the credentials of any doctor you choose.