Inspired by intraocular lenses, we have designed a foldable and photovoltaic wide-field epiretinal prosthesis (named POLYRETINA) capable of stimulating wireless retinal ganglion cells. Within a visual angle of 46.3 degrees, POLYRETINA embeds more than 6000 stimulating pixels, it is foldable to allow implantation through a small scleral incision, and it has a hemispherical shape to match the curvature of the eye. We demonstrate that it is not cytotoxic and respects optical and thermal safety standards; accelerated aging shows a lifetime of at least 2 years. POLYRETINA represents a significant progress towards the improvement of both visual acuity and visual field with the same device, a current challenging issue in the field.
Optic Nerve Stimulation
In the last decade, research on vision prosthetics has been focused primarily on retinal prostheses. However, optic nerve represents the preferred point of implantation in order to treat patients not eligible for retinal prostheses (e.g. optic nerve diseases). In our laboratory, we are developing a novel intraneural electrode array (named OpticSELINE) that is effective in inducing the activation of the visual cortex upon electrical stimulation of the optic nerve. The OpticSELINE induces selective cortical activation patterns depending on the stimulating electrode, thus suggesting that it possesses spatial selectivity in fiber stimulation.