By delivering controlled current into the eye, it is now possible to restore some level of vision to the blind. However, unlike its older brother the cochlear implant, the so-called bionic eye has not yet reached a level of maturity as to become a widely adopted therapy...
By delivering controlled current into the eye, it is now possible to restore some level of vision to the blind. However, unlike its older brother the cochlear implant, the so-called bionic eye has not yet reached a level of maturity as to become a widely adopted therapy. Possibly, one of the major challenges researchers are facing is the necessity of controlling the neural messages elicited by these devices. The healthy eye codifies transitions of light, from on-to-off and from off-to-on. Nevertheless, with the current technologies, the message thus delivered informs the brain about the light being turned off and on simultaneously. In pursuing new methods to improve the communication between the device and the brain, this project aims to generate more meaningful neural messages that could bring bionic vision closer to bionic ear. This would dramatically improve the quality of life of the visually impaired community.
It is now known that the use of high-frequency pulse trains can preferentially activate different neural pathways in the eye. In other words, by delivering fast electrical stimulation, it is possible to mimic part of the code the healthy eye uses to communicate visual information to the brain.
In addition to the enormous complexity of the neural code of the eye, there are several types of neurons in the retina which work together to codify the visual information. The final message is sent to the brain by the last cells in this cascade: the retinal ganglion cells. An important step in replicating the biological language of the eye is to understand how these cells are activated in bionic vision. The temporal response of these and the other cells in the retinal network has been characterised in vivo.
Furthermore, a secondary application of this type technology has been investigated. In particular, its application to the gastrointestinal tract. A patent application has been filed.
Patients suffering from severe visual impairment experience a decrease in the quality of their lives. In many occasions, the progression of the disease ends with the complete absence of visual sensation. Blindness can be devastating, as the person loses autonomy and independence. The research community is working in different directions to provide solutions to the nearly 100 million blind people in the globe expected by 2050. The bionic eye was the first therapy to reach the bedside, and is probably the only one that targets a broad spectrum of eye conditions. It is therefore expected that improvements in this technology cause a relevant impact in the future generations of blind people. Furthermore, the development of new stimulation techniques able to more selectively recruit the neural fibers can be exploited to other stimulation sites in pursuing treatment for other pathologies. A new discipline known as electroceuticals is rapidly evolving along with its growing industry, as it has a clear potential to deliver new solutions, not only to sensory problems but to other health conditions.