Eye Implant Stimulates Vision-Restoring Progress

A novel eye implant provides electrical stimulation of the retina that can improve visual perception in blind people with severe to profound retinitis pigmentosa (RP).

The Argus II Retinal Prosthesis System includes an antenna, an electronics case, and an electrode array, and was designed to bypass damaged photoreceptors altogether. The system is based on a video camera set in special glasses that captures a scene. The video is sent to a small patient-worn computer video processing unit (VPU), where it is transformed into excitation instructions sent back to the glasses via a cable. These instructions are then transmitted wirelessly to the antenna in the implant, which passes them to a 60-electrode grid that is surgically implanted and attached to the retina array.


The retina array emits small pulses of electricity that bypass the damaged photoreceptors and stimulate the retina’s remaining cells, which transmit the visual information along the optic nerve to the brain. Patients then learn to interpret these visual patterns, thereby regaining some functional vision. Users of the Argus II bionic eye report that the system helps them perceive rough shapes and track the movement of objects, and that they can slowly read large writing. The result delivers greater independence for patients. The Argus II Retinal Prosthesis System is a product of Second Sight (Sylmar, CA, USA).

“I started to work on retinal implants more than fifteen years ago here in Germany because I knew we could and we should help blind patients suffering from retinitis pigmentosa,” said Prof. Peter Walter, MD, of the Universitäts-Augenklinik RWTH (Aachen, Germany), one of three surgeons in Germany to have implanted Argus II in patients to date. “Today with Argus II, we can finally offer a treatment to patients backed by many years of safety and performance data.”

RP is an inherited, degenerative eye disease that causes severe vision impairment and blindness. A form of retinal dystrophy, RP is caused by abnormalities of the photoreceptors or the retinal pigment epithelium (RPE) of the retina leading to progressive sight loss. Affected individuals may experience defective light to dark or dark to light adaptation, or nyctalopia, as the result of the degeneration of the peripheral visual field (known as tunnel vision). Sometimes, central vision is lost first causing the person to look sidelong at objects.

Related Links:
Second Sight
Universitäts-Augenklinik RWTH