The Alpha IMS subretinal implant, shown in a study to restore functional vision in more than half of patients with severe retinitis pigmentosa, has been granted CE mark, according to a news release.
Thirty-six patients received the Alpha IMS (Retina Implant AG) microchip, which is a 3 mm × 3 mm, 1,500-pixel device designed to restore vision without externally visible equipment.
Each pixel has a photodiode, an amplification circuit and an electrode to allow an electrical impulse to be delivered to retinal layers corresponding to incoming light.
The chip, placed beneath the foveal region, works via inductive energy transfer from a battery pack in the control unit that allows the user to adjust brightness and contrast of perception. It offers a 10° × 10° diamond-shaped visual field that is roughly 15° diagonal.
Results from the company’s second human clinical trial of the device showed functional vision improvements, which included near vision recognition of facial characteristics and clothing patterns, as well as the ability to distinguish objects such as telephones, cutlery, door knobs and signs on doors. Far-vision improvements included ability to see the horizon and objects on the horizon.
An alternative retinal implant for patients with advanced retinitis pigmentosa is the Argus II Retinal Prosthesis System (Second Sight Medical Products), which was approved by the U.S. Food and Drug Administration in February.