Sara Ainsworth investigates how scientists are exploring retinal implants to restore vision.

Credit to Sam Bald on Flickr

According to the World Health Organization (June 2012) globally there are approximately 285 million people who are visually impaired, as well as 39 million people registered blind.

For the past few years Scientists across the globe have carried out extensive research investigating the potential of retinal implants as an innovative treatment for visual impairment. Researchers believe the implants could benefit people who suffer with the degenerative disease, Retinitis Pigmentosa. This is a hereditary disease of the retina where the light cells and colour vision photoreceptors are destroyed causing degeneration of the retina whilst the nerve cells remain intact. This results in the retina being unable to transmit images to the brain successfully.

Scientists have recently incorporated a code that transmits visual signals to the brain; the code is made up of a pattern of electrical impulses that improve prosthetic performance. Before the new encoder was explored the implants produced a myriad of light and dark spots. After the code was deciphered, tests were carried out on congenitally blind mice at the Cornell University in New York earlier this year.  Nerve cells inside the retina, known as Ganglion cells, which are responsible for the communication of visual messages, were implanted into the mice. Results showed that the animals were able to distinguish facial features and it was believed to be 90% effective.

Dianne Ashworth, an Australian woman, was the first human to successfully receive the pioneering implant at the end of last month. The ‘bionic eye’ implant was performed by the Bionic Vision Australia researchers and was funded by the Australian government. Shortly after Dianne’s implant was switched on she said “the results were amazing and it was an incredible experience.” She can now distinguish different patterns and shapes as well as differentiate light and dark objects. The bionic eye has proven to be a major breakthrough in visual prosthetics.

 

Sara Ainsworth