Thibault, 21, has benefited from this gene therapy. This young Breton received this treatment last year. He had just suffered a severe loss of vision which began while driving.

“It started with interior fog on a windshield. You can see a little blur … You can see very badly from a distance and little by little, these are things that disappear like signs … so I almost had an accident car, I almost got into a truck. From there I made an appointment very quickly. In fact I had already lost one eye, my left eye. I had 4 / 10th left in my right eye. . After that, everything deteriorates so quickly. “

Very quickly, the mist became a sort of opaque black bar. Thibault had just declared a hereditary ophthalmic neuropathy of Leber which affects the cells of the retina responsible for the center of vision.
Dr Catherine Vignal-Clermont, opthalmologist, at the Adolphe de Rothschild Foundation, specialist in this disease, explains Thibault’s symptoms.

“This impairment manifests itself by a decline in central visual acuity, which means that people keep their peripheral vision, they can see what is happening a little bit around. In the center, there is an opacity which means that the “Visual acuity is extremely poor. People will suddenly become visually impaired, it is extremely brutal after all.”

A brutal development stopped by this therapy

This approach is the result of research initiated at the Institut de la Vision and the National Ophthalmological Hospital of Quinze-Vingt.

The principle of gene therapy is to put the right gene in the right place. You must take the capsule of an inactivated virus. This transporter was designed to be injected into the eye and go to diseased cells. It must then go more precisely to the “engine” of the diseased cell, which must be repaired, the mitochondria, so that it can again function normally. The world premiere is the treatment of an airframe engine and the normal operation of the airframe.

Our team attended an injection performed by Dr Jean-François Girmins in an operating theater specially approved for gene therapy. Both Emilien’s eyes are treated under local anesthesia. The injections are very impressive, the most painful is the product used to disinfect.

Dr Jean-François Girmins, ophthalmologist, at the Quinze-Vingts national ophthalmology hospital, explains.

“The virus with the modified gene is in the syringe. We will inject 0.09 ml into the vitreous, in the middle of the eye. I am injecting very slowly because I cannot inject too quickly otherwise it will would put too much pressure in your eye. The gesture of intra-vitreous injection is very well codified now because for fifteen years, for AMD in particular, it is a very common and very common gesture. We have syringes. , needles made for that. “

Treatment action

The therapy usually works after several weeks, depending on the patient. It is necessary that the genes reach their targets and that they restart the engines of the cells. Treatment will be more effective if these engines are only idling, not completely stopped. At that time, these cells are simply “under-diet” but still alive. This means that treatment cannot be done for too long after the process has started. This is what could be achieved for Thibault, with Dr Vignal, ophthalmologist who follows the 150 patients treated in France.

“There have been spectacular recoveries, it is quite possible. But on average we are really on autonomy in daily life. I rather have a rather optimistic but measured message. Overall people are restarting, not as before, but they restart “.

Dr Vignal is both cautious and optimistic because even after treatment, these young patients almost all have to change their life plans entirely. Thibault was preparing to go to sea as captain. He hopes to find another vocation …