Wireless subretinal implant appears safe

A wireless, micrometer-sized retinal chip implanted in primates appears safe.

Pixium Vision, a French company developing innovative bionic vision systems, collaborated with scientists at Stanford University and the Vision Institute in Paris to test the safety profile of their second generation vision restoration system, PRIMA. The retinal implant contains an electrode array to wirelessly connect to a pocket computer that mimics the processing function of the retina. A pair of glasses serves as a portable visual interface with an integrated mini-camera for transmitting information to the implant.

The study, published in Biomedical Optics Express, demonstrated the thermal safety of near infrared stimulation of PRIMA in an animal model for retinal damage. The temperature increased an estimated 0.17 to 0.43°C, more than 4 times below the recommended thermal safety limit of 2°C for active implanted medical devices.

In a separate study in a primate retina without photoreceptors, scientists at the Vision Institute in Paris showed that PRIMA electrically activated the ganglion cell layers. The activation thresholds were well within the optical safety limits and primates demonstrated consistent, reproducible, spatially localized responses to projected patterns.

“We are confident that PRIMA continues to demonstrate a very positive safety profile. Pixium Vision and its partners will continue to generate further safety data to meet the company’s goal of a first PRIMA human implant in 2016,” said Khalid Ishaque, CEO of Pixium Vision.