Not a week goes by without a breakthrough involving CRISPR. From treating blood diseases to genetically editing mutated cancer cells, CRISPR research has yielded encouraging results in recent years. Researchers have already been able to restore some of their vision to patients suffering from a rare genetic condition called Leber’s congenital amaurosis, or LCA, which begins to impair vision at birth and gradually deteriorates, eventually making them legally blind.
The study was conducted in collaboration with the Casey Eye Institute at the University of Oregon Health and Science and the biotechnology startup for gene editing, Editas Medicine. After preliminary trials in non-human mice and primates were found to be safe and encouraging, a human clinical trial was organized.
Preliminary data released on Wednesday report on the results of five people. Two were given low doses of the new drug, while the other three received medium amounts. And although more research is needed, the findings could have far-reaching consequences for anyone suffering from the disease.
How CRISPR is used to give patients back some of their vision
In previous studies on diseases such as sickle cell disease, gene editing was done in the lab: Scientists had collected blood from patients, modified genes in the lab, and injected “fixed” blood cells back into the bloodstream. But this was not possible to treat the eye. So the researchers had to come up with another method of editing the genes. Using CRISPR, a harmless virus that inserts its own genome where the source of LCA disease should be located, it has been deprived of its genetic material and replaced with the altered sequence that patients need.
But that didn’t solve all the problems. The researchers still had to deliver the virus to where it was needed, the retina. This cannot be done through the bloodstream, but the cornea is a sustainable part of evolutionary mastery, so the solution can be injected directly into the cornea.
This is the first time scientists have used CRISPR in this way
The researchers were able to inject a small amount of the virus-containing solution between the cornea and the iris. The solution is applied to only one eye of the volunteers, so as not to confuse anything. Some patients do not see a change, while for some it is too early to say anything. At present, the team does not have a clear explanation for why not everyone has improved their vision, and believes that this may be due to the amount of dose or factors specific to each person’s biology. Other patients may also need more time before treatment takes effect. But the results for two of the patients are incredibly promising.
Carlin Knight, 55, of Portland, is pleased with the improvements. Her vision became clearer and brighter, and now she could look for objects instead of aimlessly reaching around. In an interview with NPRKnight said, “I’ve always loved colors. Ever since I was a child, it’s one of those things I can enjoy with just a little vision. But now I realize how much brighter they were as a child, because I see now they’re much brighter. “It’s just amazing.”
The other participant, Michael Culberer, 43, began to regain his color vision years later. “I saw the lights on the DJ’s strobe change color and identify them with my cousins who danced with me. It was a very, very fun joyful moment,” he told NPR.
Although treatment is far from treating patients in the trial, some of the changes experienced by patients are incredibly promising because they are deep enough to affect their daily lives. More patients need to be treated and monitored for a longer period of time to confirm the safety of treatment, and researchers are given permission to move on to the next group of patients.