Pixium Vision Announces Publications Demonstrating the Potential of the Next Generation PRIMA Implant

Pixium Vision announced that the second generation of implants for its bionic vision system PRIMA for atrophic age-related macular degeneration (AMD) could restore vision at five times higher resolution than the current PRIMA implants, according to a company news release.

Pixium Vision is developing the second generation of PRIMA implants in collaboration with its long-term academic partner Stanford University. A recent peer-reviewed paper published in Nature Communications, entitled "Electronic photoreceptors enable prosthetic visual acuity matching the natural resolution in rats," outlined results from the testing of the new implant in rats, which demonstrated:

• A high-resolution prosthetic vision based on a novel design of a photovoltaic array, where field confinement is achieved by dynamic current steering
• Computational modeling of the field confinement in such an optically controlled circuit validated by in vitro and in vivo measurements
• The grating acuity in vivo with 40mm pixels matches the pixel pitch, while with 20mm pixels it reaches the 28mm limit of the natural visual resolution in rats
• Customized field shaping adapting to individual retinal thickness and distance from the implant, paving the way to higher acuity of prosthetic vision in AMD patients

These results pave the way to prosthetic vision with acuity exceeding 20/100, over five times higher than the current best prosthetic acuity, and with electronic magnification, it may reach 20/20.

The full paper is available online here.

"Our new second generation PRIMA implant represents a huge leap forward in prosthetic vision and offers a real chance to restore sight close to natural vision in patients blinded by retinal degeneration," said Lloyd Diamond, Chief Executive Officer of Pixium Vision. "Working closely with our partners at Stanford University, we have leveraged the design of our existing PRIMA system, which is already the most advanced prosthetic currently in use in clinical trials. By redesigning the electric circuitry and exponentially increasing the number of electrodes in the new implant, we have achieved selective stimulation of the inner retinal neurons with five times the resolution of our current implant. With this level of visual acuity, we expect to be able to restore vision in those affected by dry AMD to the extent where they can not only read comfortably but also recognize faces, which would be an unprecedented achievement in treating blindness in these patients."

These next generation implants are now being optimized for clinical trials, which could be initiated within the next couple of years. They are based on the design of the original PRIMA implants, which were also co-developed by Pixium Vision and Stanford University. Two additional peer-reviewed papers recently published in the Journal of Neural Engineering describe how the number of pixels and the resolution of the photovoltaic retinal implants could be increased using the original (bipolar) PRIMA pixels and the novel (monopolar) pixel design in human patients.

"Pixel size limit of the PRIMA implants: from humans to rodents and back" outlines how an increase in the width of the PRIMA implant from 2 to 3 mm and a reduction in the pixel size from 100 to 75mm would nearly quadrupole the number of pixels, which would be very beneficial for patients by increasing their field of view.

The full paper is available online here.