I looked into this or a similar study at a clinic that was down in Florida, near Fort Lauderdale. The study name was SCOTS2. This was around the beginning of 2019. They answered my email in minutes at night with links to news stories, print and video, and write ups in a medical periodical. In hindsight, all fluff pieces. The cost of the study was twenty thousand dollars an eye for the stem cell.
The first red flag is you don't pay to be in a study, they usually reimburse you travel costs. You are a guinea pig for research.
The second red flag was information from my sister who does medical research at a university, that some of the medical periodicals are not legit, more like propaganda papers.
She checked with colegues in the Opthalmology department and they heard of this type of study being done at a clinic in Florida with bad outcomes and not the proper oversight from the FDA. I later learned that the FDA did not regulate stern cell research at the time. I think they do now.
Another red flag was she sent me a link to a stern cell blog from The Niche and I read them regarding the study from participants and most were negative. At least one was positive at the time. If I recall correctly, if someone went in with some vision, they came out with less vision or NO vision. I talked to one of the participants on the phone. He and his brother had one of the conditions listed for the study. They borrowed the money from a relative. The doctor said he would inject both eyes of the brother, even though the brother said just do one eye and see what happens. The brother I talked to said he would wait to see the results before he would participate. Both eyes were done and his brother lost all vision after the $40,000 spent. He also told me that one of the people conducting the study lost their medical license in New York. They did not know this until later. I googled that and confirmed it.
It is my understanding that they were using the wrong type of stem cells. I believe that the FDA now regulates stern cell research but I am not positive. I also recall seeing some news that this or a similar study was shut down by the FDA. I thought there were criminal charges also.
You should really research this if you plan to participate, especially if you still have some vision.

Is this down in Florida or New York?

Sounds similar to what ReNeuron and JCyte were/are doing. Those are stem cell treatments being developed to treat damaged/dead/dying retina though, rather than the optic nerve.

Last I checked ReNeuron is on ice following an inconclusive second stage trial. The company were looking to licence the technology out rather than continue developing it themselves because they didn't see short/mid term profitability.

Not sure on JCyte. There focus is on maintaining existing vision, or at least slowing decline, rather than recovering lost vision. Consequently, it's not relevant to me so I don't follow it.