gms | German Medical Science

Objective: To report preclinical data and outline next steps in clinical testing of the wireless sub-retinal PRIMA system.

Materials & Methods: The implant consists of photovoltaic cells that are each connected to a stimulation electrode and local return electrode. A pair of glasses called the Visual Interface contains an image sensor to capture visual information from the environment. The information is processed and then projected as near infrared images onto the implanted device. Whenever the projected infrared light illuminates a photovoltaic cell the connected electrode stimulates the adjacent retinal nerve cells electrically. Development of the next generation wireless sub-retinal PRIMA system aiming to address initially atrophic dry AMD and subsequently also Retinitis Pigmentosa, has been evaluated in different animal models. Results from pre-clinical studies covering safety, functionality and behavioral data will be presented.

Results: The sub-retinal PRIMA device was successfully implanted in 28/35 animal eyes (11 cats, 5 pigs, 19 primates) with increasing success after optimizing the surgical method. In behavioral tests, already one primate (with 100µm implant pixel) reliably responded to NIR stimulations above the implant. Natural responses to near infrared light were ruled out through several controls.

Discussion: The implantation of the next generation wireless sub-retinal PRIMA photovoltaic implant, designed with a less invasive surgical intervention, is feasible with good anatomical results. Behavioral tests results demonstrate that the PRIMA implant can stimulate indirectly retinal ganglion cells in the degenerated primate retina. These results pave the way for first human clinical trials. First in Human feasibility authorized in France and preparing also for IDE feasibility in the US.