This article may provide some insight into halting macular degeneration -- https://www.sciencedaily.com/releases/2020/01/200122122109.htm
"Gelfand was able to restore the enzyme in mice by adapting a form of gene therapy already used to treat other eye diseases in people. His work suggests that a similar approach could treat both forms of AMD, but much more testing will need to be done to determine a potential treatment's safety and effectiveness. If successful, though, it would be the first treatment for dry age-related macular degeneration and could significantly improve treatment for wet AMD."
"As it stands, patients with [wet] AMD have to undergo frequent injections into their eye, which can be painful and comes with some risks. They have to come to the eye doctor once a month or every other month. A lot of these people can't drive. So it's a huge burden," he said. "The idea behind using gene therapy like the one we propose is that one treatment would last for a very long time. It's a sustained therapy. So we can improve their vision and reduce the number of doctor's visits they have to make."