Implantable prosthesis to restore retinal-disease caused vision loss developed

Washington, May 30 : A new technique - a fully implantable visual prosthesis - developed by Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg, may offer a ray of hope for people who have lost their vision due to retinal diseases.

Experts from different disciplines, over a period 12 years, have been working to develop the new technique that may help restore vision of patients who have become blind due to retinal diseases.

The researchers tested the new technique on six patients and found that completely implantable vision prosthesis is not only technically feasible and proven functioning, it also enables the patients to perceive visual images.

The complete system comprises the implant and an external transmitter integrated in a spectacle-frame.

The implant system converts the image patterns into interpretable stimulation signals. Data and energy are transferred to the implant by a telemetric link.

The nerve cells inside the eye are then stimulated according to the captured images. Those intact cells are innervated by means of three-dimensional stimulation electrodes that rest against the retina like small studs.

"For normally sighted people that may not seem much, but for the Blind, it is a major step," said Dr. Hoc Khiem Trieu from the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg.

"After years of blindness, the patients were able to see spots of light or geometric patterns, depending on how the nerve cells were stimulated," he added.

Dr. Hoc Khiem Trieu along with Dr. Ingo Krisch and Dipl.-Ing Michael G¶rtz translated the specifications given by the medical experts and material scientists into an implant and chip design.

"A milestone was reached when the prosthetic system finally operated wirelessly and remotely controlled," said Dr. Ingo Krisch.

"A great deal of detailed work was necessary before the implant could be activated without any external cable connections," Krisch added.

"The designs became smaller and smaller, the materials more flexible, more robust and higher in performance, so that the implant now fits comfortably in the eye," said Michael Gortz.

The system benefits from a particular disease pattern, and it uses a specific operating principle to restore sight: Suffering from retinitis pigmentosa, the light sensitive cells are destroyed, but the connection of the nerve cells to the brain remains intact.

ANI