Imagine not being able to see your children, your partner or your friends and family. Imagine finding out that you would lose your vision when you had previously been able to see. This is what people face when diagnosed with retinitis pigmentosa, which is a group of inherited eye disorders that damage light-sensitive cells in the back of the eye. It is a major cause of inherited blindnessor vision loss that can occur at any age from childhood to a person’s fifties.
Vision loss severely impacts a person’s life, and even mild levels of vision loss can make it difficult to perform everyday tasks like reading signs and recognising faces. To help people with retinitis pigmentosa and other degenerative eye conditions, we conduct research and develop devices that aim to treat – and hopefully prevent – blindness and progressive vision loss.
Our ambitious vision research program currently involves two projects: development of the Australian bionic eye with a team of collaborators, and development of a novel retinal implant to delay vision loss.
Progressing Australia’s bionic eye
The Australian bionic eye has been in development for several years and the Bionics Institute is an important contributor to this challenging project. A prototype bionic eye was successfully trialed between 2012 and 2014. The prototype device was implanted in three Victorian patients with retinitis pigmentosa. It safely and effectively evoked visual images for the patients, allowing them to perceive shapes, movement and navigate around objects.
The bionic eye works by helping the brain to form a visual image when cells in the eye have been damaged by disease. It consists of a small video camera that is fitted to spectacles. The camera captures visual scenes in front of the viewer. It then sends these images to a visual processor, which converts the images into a coded pattern and sends them to a stimulator. The stimulator activates an electrode array implanted close to the retina using electrical impulses. Each electrode stimulates a nearby area of retina and the cells that project to the visual areas of the brain, evoking a localised flash of light termed a phosphene. Multiple phosphenes are created by stimulating different electrodes in rapid succession and the brain pieces these together to form a visual image.
An implant to delay blindness
We have a team of researchers investigating whether we can delay vision loss using bionic technology. The team is in the early stages of developing a world-first, tiny eye implant we have dubbed the “Minimally Invasive Retinal-degeneration Arrestor” (MIRA). MIRA aims to prolong and extend the years of useful vision by slowing the decline in patients with degenerative retinal disease using low-level electrical stimulation.
The MIRA project was awarded Best Development Grant 2016 at the highly competitive National Health and Medical Research Council (NHMRC) Research Excellence Awards. MIRA is still in the early development phase, but in addition to delaying the course of retinitis pigmentosa, researchers hope the technology may also have the potential to help people with other eye conditions including glaucoma and macular degeneration. The MIRA program arose out of work at the Bionics Institute and the Centre for Eye Research Australia (CERA) funded by the Australian Research Council (Bionic Vision Australia Consortium).