Science //


Natasha Burrows looks into this crystal ball and assesses the future for bionic vision

When Dianne Ashworth saw a ‘flash of light’ in August this year the impact was profound. Ms Ashworth suffers retinitis pigmentosa, a genetic eye disease that causes blindness. She is the first Australian to benefit from the technology developed by Bionic Vision Australia. Since 2009 the research consortium, consisting of over 100 researches primarily from the University of Melbourne and University of NSW, has been working to develop the bionic eye. Driven by the success of the Australian developed cochlear implant, the group hopes to restore vision to people who have retinitis pigmentosa and age-related macular degeneration.

The ‘eye’ as such consists of an external camera that transmits radio signals to the retina. These signals then travel down the optic nerve to the brain, where the signals are interpreted as an image. The system Ms Ashworth received is an early prototype. It does not contain an external camera. Instead, the system is externally connected to a unit with which researchers stimulate light flashes.

At this stage, the quality of the image is low compared to healthy vision. As Associate Professor Nick Barnes at Bionic Vision Australia acknowledges, “in normal human vision there are millions of visual fields that we are seeing and collating into our perception of the world.” The current technology developed by Bionic Vision Australia uses 98 electrodes. The aim is to develop technology that increases this number to 1000.

Two types of devices are being developed by Bionic Vision Australia: a ‘wide-view’ device that attempts to help patients with navigation and independence, and a ‘high-acuity’ device that aims to re-establish some functional central vision. The latter device contains a higher amount of electrodes and hopes are that it will enable patients to recognise faces and read large print. The ‘wide-view’ device only enables patients to see basic shapes and flashes of light. The bionic eye Ms Ashworth received was such a device.

While the developments so far have been impressive, the challenge remains to develop technology beyond ‘wide-view’ bionic eyes. The ‘high-acuity’ device is currently in development and trials with patients will begin in 2014.

The Australian research team is one of around 30 groups internationally developing bionic eye technology. The American developed Argus II recently gained regulatory approval to market its device.

Similar plans are in the pipeline for German implants by next year. Anthony Hall, director of ophthalmology at Alfred Hospital and associate professor at Monash University, says the race to develop the bionic eye is a “marathon”. If Australian technology continues to develop at the current rate, it is well placed to match the developments occurring overseas.

This is promising news for 50,000 Australians who suffer from blindness, and the 285 million visually impaired people worldwide.