A blind woman in China has recovered partial vision after receiving a brain-computer interface surgery in Changsha, Hunan province, bringing new hope to patients suffering from degenerative retinal diseases.
Chen, 61, was diagnosed with retinitis pigmentosa at the age of 40, a condition that eventually left her completely blind in both eyes. On April 23, she was selected for a clinical trial and underwent an implantation surgery at Xiangya Hospital of Central South University.
During the surgery, an electrode array measuring 6 millimeters by 10.8 mm — roughly the size of a fingernail — was implanted onto the retinal surface of the macular region inside the eyeball.
Following the procedure, the patient wears a pair of glasses equipped with a miniature camera and a wireless transmission module. The camera captures environmental images, which a video processor analyzes and encodes. The encoded data is then transmitted via radio frequency wireless technology to the implant, which converts the data into electrical stimulation signals that act on retinal nerve cells. This visual information is ultimately relayed to the brain.
"If we compare the eyeball to a camera, the retina is the film. When the film is damaged, we directly use electrical signals to 'tell' the intact nerve cells behind what is being seen, which is equivalent to building a bypass for the visual system," said Xu Huizhuo, who conducted the surgery and leads the clinical trial project called the IMIE intelligent retina system.
Once the system is activated, patients initially experience phosphenes — a visual phenomenon manifesting as bright pinpoint lights against a dark background. Through systematic training, patients learn to assemble these light spots to identify object outlines, obstacles, directional markers and simple letters.
Xu explained that bionic vision functions more like a low-resolution visual system delivering light and dark outlines, and cannot yet match the rich, colored vision experienced by people with normal sight.
"Nevertheless, for patients who have been blind for a long time, such visual information can greatly improve their ability to live and move around independently," Xu said, emphasizing that artificial vision helps patients regain a degree of visual perception rather than restoring normal eyesight. Patients usually require several months or longer of rehabilitation training to interpret the new information.
At present, Chen's visual acuity has recovered to 0.1. During tests, she was able to recognize striped patterns in specific orientations and complete tasks such as indoor directional walking.
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Degenerative retinal diseases like retinitis pigmentosa are major causes of irreversible blindness. Among advanced-stage patients, conventional medicines, surgeries and gene therapies often fail. The new method bypasses impaired photoreceptor cells to reconstruct an artificial visual pathway.
Remarkably, China's self-developed IMIE intelligent retina system boasts 256 stimulation channels, marking a more than fourfold improvement in data capacity compared with comparable overseas products featuring 60 channels.
"If artificial vision is compared to an electronic display screen, the number of stimulation channels is equivalent to 'pixels'. A 60-channel system is like a very blurry black-and-white image, whereas the 256-channel version delivers far more details," Xu said.
The team has already completed the development of 512-channel flexible electrode technology, aiming for future iterations ranging from 1,024 to 2,048 channels. The technology is applicable to patients whose optic nerves and brain visual pathways remain functional. As the system is still in the clinical research stage, relevant costs will be finalized following subsequent regulatory approvals.
Contact the writers at chenmeiling@chinadaily.com.cn
