Vision is a complex and fragile process. Light enters through the front of the eye and is precisely focused onto the retina, the back, inside layer of the eye. The retina translates it into electrical signals so it can travel through the optic nerve to the brain. If any of these parts are damaged, your vision could be severely affected. What would you do then?
Artificial eyesight sounds like something straight out of the movies, but for people who have lost their sight it is an idea that brings hope. OSU ophthalmologists are collaborating with scientists on the other side of the globe to restore vision loss in their patients.
Qiushi Ren, PhD the Chairman of Biomedical Engineering at Peking University in Beijing is pioneering an artificial vision initiative known as the China Eye Project, which uses a direct optic nerve stimulation device. The device is a tiny electrode which translates images from a remote camera into electrical signals which travel through living fibers of the optic nerve to the brain. While it does not bring the vision back to normal, it can provide some level of visual perception.
An optic nerve stimulation device bypasses the entire eye which makes it a good solution for ocular trauma patients.
“The problem is,” said OSU researcher Dr. Cynthia Roberts, “most Chinese surgeons do not actually operate on the optic nerve. It is sort of a forbidden area for them.”
Because of this social stigma, Professor Ren approached Dr. Roberts and Dr. Steven Katz, an OSU neuro-ophthalmologist, to discuss an international collaboration for the China Eye Project. His interest stemmed from Dr. Roberts' expertise in biomedical engineering and the large volume of optic nerve surgeries that Dr. Katz has performed.
“I understood anatomically what he wanted,” said Dr. Katz. “I could also explain why some of the things they previously tried weren’t working and what I thought they should do to be successful.”
Dr. Katz and Dr. Roberts traveled to China in January and gave presentations to the Department of Biomedical Engineering at Peking University in Beijing and the Department of Ophthalmology at the People’s Number One Hospital in Shanghai.
Dr. Katz spent time in the lab trying to demonstrate a minimally invasive approach to the optic nerve for the China Eye Project. This enabled him to demonstrate how to expose the optic nerve so the device could be attached without having to go through bone.
“It was difficult to communicate while engaged in a delicate surgical procedure,” said Dr. Katz. “They were very gracious and everywhere we went there was someone helping us communicate or someone who spoke English."
Once he had determined the best surgical method, Dr. Katz was able to perform live surgery on an animal model to expose the optic nerve and train local surgeons who were observing the procedure. Photographs were then taken of the microelectrode array sitting on the optic nerve to serve as a size reference.
“The key issues are what kind of exposure we can get to the optic nerve,” said Dr. Katz. “How do we fabricate the device so it can be easily implanted, and how do we attach it to minimize movement.”
In the initial phase, researchers are using a penetrating electrode. Future plans include the use of an electromagnetic field that can stimulate the individual axons in the optic nerve. Dr. Katz is currently developing new surgical instruments that are smaller and more delicate for the purpose of this procedure. Two sets of instruments will be manufactured, one for Columbus and one for Shanghai. Another trip to China is planned for late June, where the first device will be implanted in an animal subject. Ultimately, Dr. Katz will use the successful animal trials to seek approval for implanting the device into humans. Once approved, he will perform the human studies at Ohio State.