Most forms of blindness, including macular degeneration and retinitis pigmentosa, result from the degeneration of light sensing receptor cells at the back of the eye. The neural pathways that convey information from the eye to the brain however, often remain intact.
The Wyss Center is supporting development of a bionic implant that will bypass damaged optical cells and restore lost vision by directly stimulating the optic nerve.
Led by Professor Diego Ghezzi, in collaboration with Professor Silvestro Micera, both from the Center for Neuroprosthetics at the École Polytechnique Fédérale de Lausanne, the project aims to develop a system that will convert images captured with a head-mounted camera to a pattern of electrical signals.
A bionic implant that will bypass damaged optical cells and restore lost vision by directly stimulating the optic nerve
These signals will be relayed to an electrode implanted in the optic nerve, stimulating the nerve fibers. The information will then be transmitted along the optic nerve to the brain where it is interpreted as sight.
A flexible electrode array will allow the electrodes to be implanted into different regions of the optic nerve. This will enable the stimulation of nerve fibers, making the system able to treat several different disorders.
One of the most innovative aspects of this project is that real time feedback from the electrode array will be processed by an implanted microprocessor to adjust and optimize the patient’s vision.
Once the topic of folklore and science fiction, the notion of restoring vision to the blind is now approaching a tractable reality. Technological advances have inspired numerous multidisciplinary groups worldwide to develop visual neuroprosthetic devices that could potentially provide useful vision and improve the quality of life of profoundly blind individuals.
While a variety of approaches and designs are being pursued, they all share a common principle of creating visual percepts through the stimulation of visual neural elements using appropriate patterns of electrical stimulation. Human clinical trials are now well underway and initial results have been met with a balance of excitement and cautious optimism. As remaining technical and surgical challenges continue to be solved and clinical trials move forward, we now enter a phase of development that requires careful consideration of a new set of issues.
Establishing appropriate patient selection criteria, methods of evaluating long-term performance and effectiveness, and strategies to rehabilitate implanted patients will all need to be considered in order to achieve optimal outcomes and establish these devices as viable therapeutic options.
Credit : Wyss Center