Early tests of a ‘bionic eye’ developed by Australian researchers have successfully stimulated limited visual sensation in people suffering a rare form of genetic blindness.
Scientists from the Bionic Eye Foundation at Sydney’s Prince of Wales Hospital have launched human clinical trials of the device, which employs the same technology now routinely used in cochlear implants to restore hearing.
Minas Coroneo said the trials involved placing small electrodes on the surface of the eye. An electric current was then used to stimulate the retina – the thin layer of cells in the back of the eye that respond to light.
Coroneo said a video camera attached to a pair of glasses was used to pick up images and transfer them to the electrodes via a computer.
The electrodes then stimulated the retina to send messages down the optic nerve to the visual area of the brain.
While it does not offer full sight, Coroneo said it could one day provide blind people with enough "functional vision" to negotiate their way across a room without bumping into objects.
"The patient will see a pattern of flashes that will outline objects," he said. "[Our] aim is getting seeing-eye dogs back to being just pets."
The stimulation achieved so far is extremely limited, but researcher Vivek Chowdhury said it was enough to spark a tearful response from his first successful patient, who saw a single spot of light after years of living in darkness.
"It’s a combination of excitement and surprise and shock, it’s quite scary to be seeing these things that they haven’t seen before," said Chowdhury.
Coroneo said the prototype bionic eye was a low-risk device for patients because it sat on the eye’s surface and did not require invasive surgery.
He said it was an exciting development for people suffering conditions such as retinitis pigmentosa, an irreversible genetic condition where the retina’s cells gradually die but the optic nerve survives.
The researchers are also developing a second type of bionic eye that involves electrodes implanted directly onto the brain’s visual area, meaning it could help patients whose optic nerve has been destroyed.
