At the moment, we are unable to cure blindness attributed to lesions of the retina. However, a new strategy for an experimental treatment offers a ray of hope: retinal prosthesis.
The retina is a thin layer of light-sensitive neural cells that covers the back of the eyeball. These cells capture light signals, changing them into a message that is then transmitted to the brain by the optic nerve.
To restore the sight of a person suffering from a damaged retina, researchers have imagined a retinal prosthesis that could replace light-sensitive cells. The system would be able to capture images and transform them into electrical signals that would stimulate the neurons of the internal retina. The experimental devices currently consist of glasses whose arms are equipped with mini-cameras that are connected to a microprocessor. The microprocessor then decodes the images recorded by the camera, and transmits them via a cable implanted in the retina. Then, this retinal prosthesis stimulates the residual retinal neurons in order to produce images at the brain level.
Therefore, a retinal prosthesis could restore the priceless sight of blind patients whose internal retinal neurons remain functional (such as macular degeneration caused by ageing). However, these prostheses would be useless for diseases such as glaucoma, in which the optic nerve is affected, or diabetic retinopathy, in which the internal retinal neurons are damaged.
Feasibility studies, along with studies evaluating the effects such devices could have on human vision, are set to begin shortly with various prototypes. For now however, it is difficult to predict just when these systems could become widely available. This is definitely a very interesting discovery that deserves our full attention!