Mélange Accessibility for All Magazine January 2022 | Page 37

To Table of Contents to pathology and machine learning . Together with 15 early-stage researchers , they are working on novel technologies for restoring patients ’ vision .
‘ It may sound a little like science fiction ,’ said Picaud , describing the prostheses at the retinal and cortical level ( cerebral cortex or outermost layer of the brain ).
‘ Currently , there are no commercial cortical prostheses , so this research provides a major opportunity to develop them , and we have a team working on this ,’ he explained .
For millions of patients who are losing their sight or are already blind due to a damaged connection between the retina and visual cortex , a cortical prothesis is the only option .
Seeing is believing The idea to electrically stimulate the human visual system is not new – it was first described more than 200 years ago . But rapid advances in neural engineering and microelectronics have paved the way for more advanced corticallybased visual prosthetic devices .
‘ The idea is to use a type of electronic device to electrically stimulate the remaining nerve cells . So , after having lost part of the “ circuit ”, you replace it with an electronic device ,’ said Picaud .
One of the ENTRAIN VISION partners recently implanted a microelectrode array composed of 100 microneedles into the visual cortex of a blind woman . With the implant , she was able to identify lines , shapes and simple letters . ‘ These results are very exciting because they demonstrate both the safety and efficacy of this technology and can help to achieve a longheld dream of many scientists : to transfer information from the outside world directly to the visual cortex of blind individuals , restoring a rudimentary form of sight ,’ explained Picaud . ‘ This work is likely to become a milestone for the development of new technologies that could help to transform the treatment of blindness . However , more studies are still needed .’
The use of electrostimulation to recover an individual ’ s sight is just one novel approach being studied , but there are others .
Developed in the 2000s , optogenetics is a biological technique that uses light to controls nerve cells or other cell types .
‘ There is already one patient in France who can see using this ,’ highlighted Picaud .
The patient Picaud refers to was diagnosed with the neurodegenerative eye disease retinitis pigmentosa , which affects more than two million people worldwide destroying their retinal photoreceptors .
Thanks to groundbreaking research with Gensight Biologics , the patient ’ s sight has been partially restored using light-sensing proteins first found in algae .
The third exciting technology that researchers have set their sights on is virtual reality .
‘ In Paris we have a setting like a movie theatre ( Streetlab ) where we can test a patient ’ s vision ,’ explained Picaud . ‘ It could be , for example , a room full of obstacles . So , once the patient has a device implanted , we can test it using this platform . However , it ’ s not easy to validate a device in other centres outside of Paris , because the platform cannot be easily recreated elsewhere due to its size . This is where virtual reality steps in .’
For instance , a virtual reality headset can allow users anywhere in the world to experience the same conditions as those in the Paris theatre . ‘ It can also help us understand what the most important parts of an image are for a patient so that they can recognise their friends or ways to move about a room ,’ added Picaud .
Such technologies will help people suffering from loss of sight to regain their independence . But what happens if both sight and hearing – our two most important senses – are severely impaired ?