gms | German Medical Science

In 2015, some teams were trying to give back some sight to patients deeply blind by retinal diseases such as advanced stages of retinitis pigmentosa. Regardless of the epi or subretinal localization of the electrodes, most of the results confirmed that 1. stimulation of ganglion cells could give some visual perceptions in patients with bare light perception 2. that complications could arise from the wire connecting the retinal implant to the outside of the eye, either bringing energy or stimulation or both to the system.

At this time, Prof. D. Palanker in Stanford published the first papers about a wireless photovoltaic system able to stimulate the remaining ganglion cells of the retina by pulsed near-infrared light when implanted underneath the atrophic macula. In collaboration with D. Palanker, we made a series of animal studies 1. to design the surgical technique for implantation 2. to confirm the possibility of stimulation 3. to define the parameters of stimulations 4. to control the tolerance of the subretinal chip. The chosen nickname of the system was PRIMA.

The animal studies were performed in the USA and France and, after 2 years, the encouraging results allowed us to go to the first human study of feasibility and safety which was started in December 2017.

We present here the results of these different studies allowing now to start a larger multicenter European study, the Primavera study.