An estimated 15 million Americans are affected by macular degeneration, an irreversible condition and the leading cause of blindness in people over the age of 60.
Macular degeneration occurs in the retina, the very delicate tissue located at the back of the eye. When the nerve cells in the center of the retina – the macula – degenerate, the pathway to the optic nerve is interrupted. As a result, the brain no longer receives signals that can be converted to visual images.
While less common, Retinitis Pigmentosa also results in retinal degeneration. The disease affects children and adults, and it progresses quickly, typically resulting in blindness by the age of 40. An estimated one in 4,000 people suffer from Retinitis Pigmentosa.
Shawn Kelly, PhD, is Senior Systems Scientist at Carnegie Mellon University’s Institute for Complex Engineered Systems. Dr. Kelly has dedicated his nearly 20-year research career to the cause of restoring vision to those impacted by macular degeneration. The research project took root at the Massachusetts Institute of Technology (MIT), where Dr. Kelly committed his graduate and doctoral studies to the development of a retinal prosthesis that would restore a measure of functional sight.
In 2011, he transferred his research to Carnegie Mellon University (CMU). Today, he continues his work as part of a multi-disciplinary team that includes a dozen researchers from CMU, MIT and Cornell University.
The retinal prosthesis is an implantable electronic device that bypasses the non-functioning retina by creating and sending electronic signals to the optic nerve. Researchers have spent years tackling a multitude of complex challenges, including the wireless delivery of power to the ocular nerve cells, the implantation of the device in a very small cavity at the back of the eye and the safety of the device over the course of the user’s lifespan.
During initial clinical trials, electrodes were inserted into the eyes of blind people for a few hours to prove the feasibility of an implantable retinal prosthesis. Now, the team is working with the FDA to gain approval for a much more extensive round of clinical trials, a process that could take another two years.
In the meantime, the team has reduced the size of the implantable device, created a new and safer titanium case, advanced microchip technology and fabricated new and improved electrodes.
In the next round of clinical trials, the number of electrodes will be increased from 15 to more than 200, in order to restore a more functional level of vision.
Because natural vision is driven by millions of photo receptor cells, researchers understand that the replacement of a few hundred will result in pixelated images. Restoring enough vision to maneuver safely through the tasks of daily life, however, is reason enough to keep Dr. Kelly committed to his research, even if that means another 20 years.