The U.S. Department of Energy has awarded major responsibility for the development of a third-generation retina prosthesis to Lawrence Livermore National Laboratory (LLNL, Livermore, Calif.). The third-generation artificial retina will enable previously blind people to read, recognize people's faces and restore mobility so that people can navigate about the world again using their sight.
Artificial retina team member Terri Delima holds a thin-film artificial retina array fabricated at the Lawrence Livermore National Laboratory.
The retinal implant is designed for the millions of patients worldwide suffering from retinitis pigmentosa and age-related macular degeneration, since it implants an electrode array atop the old damaged retina to stimulate the undamaged nerve ganglia lying underneath, with image information wirelessly transmitted to it from a video camera mounted on a pair of eyeglasses.
The first-generation implants were successfully tested on six patients, but only held 16 electrodes (4-by-4-pixel array), which enabled the crude perception of lighted areas versus darkness after about 15 seconds. The second-generation implant upped the electrode array to 60 electrodes, which enabled 34 test patients to recognize doorways and windows as well as the edges that assist in navigation, such as walls and low-lying branches, after about 3 seconds.
The goal of the third generation of the implant will be to increase the electrode array to more than 200 electrodes, which will enable the near instantaneous recognition of text for reading, pictures and all the edge cues needed to navigate the world unaided. Ultimately, the artificial retinal will contain over 1,000 electrodes, which should restore instantaneous recognition of faces and other fine details that should fully integrate patients back into everyday society.
The artificial retinas are being fabricated on silicon wafers by LLNL with the assistance of four other national laboratories, four universities and a private company, Second Sight Medical Products (Sylmar, Calif.), the latter of which will be responsible for commercializing the third-generation device, including performing all the field trials necessary to obtain full Food and Drug Administration (FDA) approval.
Also instrumental in the third-generation device will be the Doheny Eye Institute, at the University of Southern California (Los Angeles), which will provide the clinical testing of the electrode array implants, and Argonne National Laboratory (Illinois), which will use its ultrananocrystalline diamond film technology to hermetically seal the package for the prosthetic device to protect it from the salty environment inside the eyeball.
The third-generation retinal implants are fabricated 12 at a time on silicon wafers using LLNL's polymer-based micro-fabrication techniques. The entire retinal implant assembly is composed of a thin-film electrode array that contains the neural electrodes and a biocompatible package that contains the electronics for stimulating the retina, as well as a wireless receiver for powering the device and receiving the image data from the camera. LLNL is also developing a companion ocular surgical tool that will enable the easy insertion and attachment of the thin-film electrode array inside the eye.
Other project contributors include Los Alamos National Laboratory, Oak Ridge National Laboratory, Sandia National Laboratory, California Institute of Technology, North Carolina State University and the University of California at Santa Cruz