The Prima System :

The Prima System is a Bionic VIsion System intended to replicate the physiological functions of the eye’s photoreceptors by electrically stimulating the retinal cells, which then transmit the visual information to the brain via the optic nerve.

The technologies currently focus on the disorders resulting from degeneration of photoreceptors (especially dry Age-related Macular Degeneration).

Structure of the retina:

The retina is composed of several layers of cells that line the back of the eye. The layer of photoreceptor cells converts light stimuli into electrical signals. These signals are then sent to the cells forming the inner retina, where they undergo spatial and temporal processing before being transmitted to the ganglion cells located on the surface of the retina and whose axons form the optic nerve. Lastly, the optic nerve transports the final signal to the visual cortex deep in the brain.

Photoreceptor degeneration:

Most degenerative diseases of the retina (whether of genetic origin or age-related) result from the progressive or acute degeneration of photoreceptor cells; the retina can no longer convert light stimuli into electrical signals.

This degeneration of photoreceptors leaves the other retinal cells, whether ganglion cells or the inner retina, functional. Consequently, when these inner retinal cells are electrically stimulated, a visual stimulus can still be transmitted to the brain.