London, May 5: The first synthetic, soft tissue retina developed by Oxford University researchers could offer fresh hope to visually impaired people. Until now, artificial retinas have only been made from hard, rigid materials.
The new research is the first to successfully use biological, synthetic tissues, developed in a laboratory environment. The study could revolutionise the bionic implant industry and the development of new, less invasive technologies that more closely resemble human body tissues, helping to treat degenerative eye conditions such as retinitis pigmentosa.
Just as photography depends on camera pixels reacting to light, vision relies on the retina performing the same function. The retina sits at the back of the human eye, and contains protein cells that convert light into electrical signals that travel through the nervous system, triggering a response from the brain, ultimately building a picture of the scene being viewed.
Vanessa Restrepo-Schild led the team at Oxford University in the UK which developed the synthetic, double layered retina which closely mimics the natural human retinal process. The retina replica consists of soft water droplets (hydrogels) and biological cell membrane proteins. Designed like a camera, the cells act as pixels, detecting and reacting to light to create a grey scale image.
"The synthetic material can generate electrical signals, which stimulate the neurons at the back of our eye just like the original retina," said Restrepo-Schild.
The study, published in the journal Scientific Reports, shows that unlike existing artificial retinal implants, the cell-cultures are created from natural, biodegradable materials and do not contain foreign bodies or living entities. The implant is less invasive than a mechanical devise, and is less likely to have an adverse reaction on the body.
"The human eye is incredibly sensitive, which is why foreign bodies like metal retinal implants can be so damaging, leading to inflammation and/or scaring.
"But a biological synthetic implant is soft and water based, so much more friendly to the eye environment," Restrepo-Schild added.
At present the synthetic retina has only been tested in laboratory conditions, and researchers want to explore potential uses with living tissues.
The next step is vital in demonstrating how the material performs as a bionic implant, researchers said.
They have filed a patent for the technology and the next phase of the work will see the Oxford team expand the replicas function to include recognising different colours.
Working with a much larger replica, the team will test the materials ability to recognise different colours and potentially even shapes and symbols.
Further research will expand to include animal testing and then a series of clinical trials in humans.