The DOE Artificial Retina Project was 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 was to design a device to help restore limited vision that enables reading, unaided mobility, and facial recognition.
The device is intended to bypass the damaged eye structure of those with retinitis pigmentosa and macular degeneration. These diseases destroy the light-sensing cells (photoreceptors, or rods and cones) in the retina, a multilayered membrane located at the back of the eye. For more information, see How the Artificial Retina Works.
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, more than 30 additional volunteers around the world have had first- or second-generation (60-electrode) 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 also were 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.
Argus™ I is pictured above. A retinal prosthesis contains a small implantable chip with electrodes. These electrodes stimulate the retina and help people regain limited vision.
Three models in testing and development
Model 1 (Argus™ I)
The Model 1 device [developed by Second Sight™ Medical Products, Inc. (SSMP)] was implanted in six blind patients between 2002 and 2004, whose ages ranged from 56 to 77 at time of implant and all of whom have retinitis pigmentosa. The device consists of a 16-electrode array in a one-inch package that allows the implanted electronics to wirelessly communicate with a camera mounted on a pair of glasses. It is powered by a battery pack worn on a belt. This implant enables patients to detect when lights are on or off, describe an object’s motion, count individual items, and locate objects in their environment. To evaluate the long-term effects of the retinal implant, five devices have been approved for home use.
Model 2 (Argus™ II)
The smaller, more compact Model 2 retinal prosthesis (developed by SSMP with DOE contributions) is currently undergoing clinical trials to evaluate its safety and utility. This model is much smaller, contains 60 electrodes, and surgical implant time has been reduced from the 6 hours required for Model 1 to 2 hours.
The Model 3 device, which will have more than 200 electrodes, has undergone extensive design and fabrication studies at the DOE national laboratories and is ready for preclinical testing. The new design uses more advanced materials than the two previous models and has a highly compact array. This array is four times more densely packed with metal contact electrodes and required wiring connecting to a microelectronic stimulator. Simulations and calculations indicated that the 200+ electrode device should provide improved vision for patients.
DOE role and funding
DOE supported the design, construction, and some preclinical (nonhuman) testing of the devices. Funding was for research in the following areas:
During the funding period, the DOE Office of Science project grew from a pilot funded at $500,000 (FY 1999) to a full-scale effort with support of roughly $7 million per year. DOE funding for the project ended in FY 2011.
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.
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).]
Base URL: http://artificialretina.energy.gov
Last modified: Tuesday, May 15, 2018