The breakthrough in gene therapy helps the blind to see again – after 40 years of Science & Tech News
A blind man regained some sight in one eye thanks to an innovative treatment with genetic engineering and light-activated therapy.
The 58-year-old, who lives in France, was diagnosed with retinitis pigmentosa (RP) almost 40 years ago, a neurodegenerative eye disease that affects the retina in the back of the eye and affects its function.
After the treatment, however, he was able to see, count, locate and touch various objects with the treated eye while wearing light-stimulating goggles.
RP is a condition in which the cells in the retina that are receptive to light are broken down, which can lead to complete blindness.
It is the most common inherited eye disease that affects around 1 in 4,000 people in the UK.
There is no approved treatment for RP other than gene replacement therapy, which only works for an early-onset form of the disease.
The new evidence, published in the journal Nature Medicine, is still in its early stages, but the scientists’ work could be seen as a stepping stone to new targeted treatments for people with the disease.
The researchers used a technique known as optogenetics to genetically modify cells in the retina to produce light-sensitive proteins called channelrhodopsins.
The treatment, done using an injection in one eye, made possible a gene that codes for a channelrhodopsin protein called ChrimsonR, which senses amber light.
The team also developed special protective goggles with a camera that records visual images using wavelengths of amber light and projects them onto the retina.
The patient was then trained for several months when the genetically modified cells began to stabilize.
Seven months later, it showed signs of visual improvement, the researchers said.
The team said his patient was “very excited” after his first post-treatment experience with partial vision as he watched the white streaks of a pedestrian crossing in the street.
The researchers also took measurements of his brain activity using a technique known as electroencephalography (EEG).
A cup was alternately taken on or off the table and the patient had to press a button to indicate whether it was present or not.
The results of the experiments showed that he could determine with an accuracy of 78% whether the cup was present or not.
Botond Roska, Founding Director at the Institute for Molecular and Clinical Ophthalmology Basel and Professor at the University of Basel, Switzerland, said: “The results provide evidence of the concept that optogenetic therapy can be used to partially restore vision.”
Jose-Alain Sahel, Professor and Chair of Ophthalmology at the University of Pittsburgh, said, “Importantly, blind patients with different types of neurodegenerative photoreceptor disease and a functional optic nerve may be eligible for treatment.
“However, it will be some time before this therapy can be offered to patients.”