London doctors became the first in the world to cure blindness in children born in rare genetic conditions using pioneering gene therapy.
The children suffered from Laber congenital amouris (LCA), a severe form of retinal dystrophy that causes vision loss due to defects in the AIPL1 gene. The affected individuals are legally recognized as blind from birth.
However, after a doctor injects healthy copies of the genes in a keyhole surgery that took just 60 minutes, four children can see shapes, find toys, recognize parents' faces, and sometimes can even read and write.
“The results for these children are very impressive and show the power of gene therapy to change lives,” says Moorfields Eye Hospital, consultant retinal specialist and professor of ophthalmology, UCL Institute of Ophthalmology Professor Michel Michaelides said.
“For the first time, we have an effective treatment of the most severe forms of childhood blindness and a potential shift in paradigms to treating the earliest stages of illness.”
One to two children in the US, Türkiye and Tunisia, were selected in 2020 by experts from Moorefield and UCL.
A healthy copy of the AIPL1 gene contained in harmless viruses was injected into the retina, a photosensitive layer of tissue behind the eye.
This gene is essential for the function of photoreceptors and is a photosensitive cell in the retina that converts light into electrical signals that the brain interprets as visual.
Treatment was administered only one eye per patient to overcome potential safety issues. The children were then followed up for five years. The result was Featured in the Lancet Journal.
Professor James Bainbridge, a consultant retinal surgeon at Moorefield and professor of retinal research at UCL Ophthalmology Institute, says that children born with LCA can only distinguish between light and dark, and that they will lose within a few years. There are almost none.
“Some children can even read and write following the intervention.
The parents of one of the children described the outcome as “pretty surprising” and said they felt “lucky” to receive the benefits. Her six-year-old son Jace had two when he was treated, but they were able to pick up small items from the floor and identify toys in the distance.
Unwilling to share their last name, Brendan and DJ traveled from Connecticut, USA in September 2020 for treatment.
“Before the surgery about two years ago, he could have lifted any object, even a few inches away from Jace's face. He couldn't track it,” DJ said. “It didn't matter how bright it was, what colour it was, what shape it was.
“And now we've got a call and a note from the school and he's stealing the phone from the teacher's back pocket. This is hysterical for us.”
Brendan said he noticed the difference within the first month his son responded to the sun glowing through the window. “He pulled himself back. It wasn't just his eyes closed, it was a more physical response.
“And I remember being uplifted and really emotional because it was the first time Jace had responded to any kind of light stimuli and anything like that. From there, it was pretty amazing. That's what it is.”
UCL developed the treatment using a special license granted by the Medicine and Health Care Regulatory Agency (MHRA) and supported by gene therapy company Meiragtx.
Since the four children were treated, seven more have been treated at Everina London Children's Hospital by experts from St. Thomas Hospital, Great Ormond Street and Moorefield.
