Bionic eyes: Changing the lives of those living in the dark

Put simply, a bionic eye is an electrical prosthetic that is designed to work inside the existing eye structure or in the brain.

At the beginning of the year, an 88-year-old woman was the first UK patient to receive a new bionic implant as part of a clinical trial. Blind in her left eye due to a common form of dry age-related macular degeneration (AMD), the procedure took place at Moorfields Eye Hospital and involved creating a ‘trapdoor’ under the retina into which a 2mm chip was inserted. Special glasses with a video camera connected to a small computer attached at the wearer’s waist allowed the patient to detect signals where she couldn’t before.

The device used in this operation was developed by Pixium Vision. The company states that its Prima System “is intended to partially replace the normal physiological function of the eye’s photoreceptor cells by electrically stimulating the nerve cells of the inner retina, which then transmit the visual information to the brain via the optic nerve”.

A similar innovation in this field comes from a team of researchers at the University of Sydney and the University of New South Wales. They have created a bionic eye system called Phoenix99 that is designed to partially restore vision for those who suffer from vision impairment or blindness caused by diseases. The device involves attaching a stimulator to the eye and a communication module under the skin behind the ear.

The researchers successfully tested the device on a small flock of sheep, surgically implanting the bionic eye and monitoring its performance for up to three months. Says Samuel Eggenberger, a biomedical engineer at the University of Sydney: “Importantly, we found the device has a very low impact on the neurons required to ‘trick’ the brain. There were no unexpected reactions from the tissue around the device and we expect it could safely remain in place for many years.

“Our team is thrilled by this extraordinary result, which gives us confidence to push on towards human trials of the device. We hope that through this technology, people living with profound vision loss from degenerative retinal disorders may be able to regain a useful sense of vision.” The research was published in Biomaterials.

Another bionic eye that has been in the news recently is the Argus II from US company, Second Sight. This system has already been fitted to more than 350 people worldwide, but as IEEE Spectrum reports, the company discontinued the implants in 2019 and almost went out of business in 2020. This means that no repairs or replacements are possible, effectively leaving its users ‘in the dark’.

Second Sight said in a statement that the company “will continue to explore opportunities intended to create artificial forms of useful vision for the profoundly blind”. It is currently working on a brain device called Orion that aims to bring artificial vision to the blind. The company states that Orion “has the potential to treat a much larger patient population than that associated with the Argus II”.

Second Sight patients have voiced concerns, however. One such person, who was contacted by IEEE Spectrum, explained that in November 2020 the video processing unit broke in his implanted Argus II system. He said that he was left with no vision and no support from the company.

Second Sight announced a merger earlier this month with Nano Precision Medical (NPM) and Adam Mendelsohn, Chief Executive of NPM told the BBC that these issues raised would be considered once the merger was complete in mid-2022.