Scientists from Johns Hopkins have found a therapy that can actually preserve the vision of patients suffering from a form of age-related blindness.
Wet age-related macular degeneration (AMD) is one the leading causes of vision loss. In the US alone it affects an estimated 1.6 million people.
To combat the vision loss patients are required to have regular injections of a therapeutic protein that reduces fluid in the macula and improves vision. Unfortunately the procedure is uncomfortable, and as the researchers point out many patients will miss appointments because of this. The alternative however is vision loss.
The breakthrough here is that rather than forcing the patient to go through regular injections of the protein, they can actually turn the eye into a factory for producing it.
To do this they inject the eye with a virus (similar to that of the common cold) which just so happens to be carrying a gene that when deposited, tasks the retinal cells with producing the protein.
The patient wouldn’t get sick from the virus as it has already been genetically altered to be harmless, and by turning the eye into a protein factory the researchers have effectively eliminated the need for constant injections.
“This preliminary study is a small but promising step towards a new approach that will not only reduce doctor visits and the anxiety and discomfort associated with repeated injections in the eye.” said Professor of Ophthalmology at the Johns Hopkins University School of Medicine Peter Campochiaro, M.D.
While the process works in theory there are some major hurdles to overcome first.
For starters the researchers found that some of the patients involved in the testing already had antibodies against the virus they were using to deliver the gene.
That meant that their immune system’s destroyed the virus before it had a chance to deposit the gene and start the protein production.
Campochiaro explains, “The numbers are small and simply show a correlation, so we don’t know if serum antibodies are definitely an impediment, but more work is needed to determine this.”