The DOE Artificial Retina Project is a multi-institutional collaborative effort to develop and implant a device containing an array of microelectrodes into the eyes of people blinded by retinal disease. The ultimate goal is to design a device with hundreds to a thousand microelectrodes. This resolution will help restore limited vision that enables reading, unaided mobility, and facial recognition.

History
The DOE project builds on the foundational work of its leader, Mark Humayun at the Doheny Eye Institute of the University of Southern California. In a breakthrough operation performed in 2002, a team led by Humayun successfully implanted the first device of its kind—an array containing 16 microelectrodes—into the eye of a patient who had been blind for more than 50 years. Since then, over 20 additional volunteers around the world have had first or second generation devices implanted. These devices enable patients to distinguish light from dark and localize large objects. For more information, read patient stories.

Integrating revolutionary DOE technologies for useful vision
Achieving the quantum improvements in resolution needed for useful vision requires the integration of revolutionary technologies such as those developed at DOE national laboratories. In 1999, the Doheny group began collaborating with researchers at DOE’s Oak Ridge National Laboratory, who were also working on approaches for restoring sight to the blind. Shortly thereafter they began to evaluate technologies at several other national laboratories as well.

To speed the design and development of better models, in 2004 Doheny and DOE (including six of its national laboratories), two additional universities, and Second Sight Medical Products Inc. (a private-sector company) signed a Cooperative Research and Development Agreement. Under the agreement, the institutions jointly share intellectual property rights and royalties from their research. This spurs progress—freeing the researchers to share details of their work within the collaboration.

Three models in testing and development
Three models are now in development or testing. Model 1, with 16 electrodes, was implanted in six patients. In addition to providing rudimentary sight for the patients, this apparatus is beginning to answer important fundamental biological questions that will enable researchers to go much further in developing this concept.

Clinical trials for a second device with 60 electrodes are under way with U.S. Food and Drug Administration approval. As of March 31, 2009, 21 people with retinitis pigmentosa have been implanted with the device, and this number continues to rise as more participants are enrolled in the trials.

A third, higher-resolution model is under development.

• Neuroscience imaging studies on Model 1
• Some preclinical animal studies of Model 2
• Design and fabrication studies of Model 3

Over the past several years, the DOE Office of Science project has grown from a pilot funded at $500,000 (FY 1999) to a full-scale effort with current support of $6.8 million (FY 2007).

Synergies with others
Doheny also receives other federal funding to support and extend the work on the retinal and other neural prostheses. The National Eye Institute of the National Institutes of Health, for example, supports fundamental and applied research related to the prosthesis.

Additionally, the National Science Foundation provides funding for the longer-term goals of further enhancing the retinal prosthesis and adapting the technologies to treat a wide range of other neurological disorders. For example, researchers are studying how the foundational concepts used to create the retinal prosthetic can be used to reanimate paralyzed limbs and even restore short- and long-term memory for stroke and dementia (as in Alzheimer’s disease). For more details, see Biomimetic MicroElectronic Systems.

Worldwide projects
Other retinal prostheses projects are under way in the United States and world-wide, including Germany, Japan, Ireland, Australia, Korea, China, and Belgium. These programs pursue many different designs and surgical approaches. Some show great promise for the future, but have yet to demonstrate practicality in terms of adapting to and lasting long-term in a human eye. Thus far the projects that have progressed to clinical (human) trials are the collaborative DOE effort, a project at the now-defunct Optobionics (Chicago), and two efforts in Germany at Intelligent Medical Implants AG and Retinal Implant AG. [For more information on worldwide projects, see Science 312, 1124-26 (2006).]