| Overview
of the
Artificial Retina Project
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.
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A retinal prosthesis contains a small implantable chip with
electrodes. These electrodes stimulate the retina and help
people regain limited vision. The artificial retina devices
developed in this study offer hope to people suffering from
diseases that cause blindness but leave the cones and rods
(cells that detect light) intact. |
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
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.
DOE role and
funding
DOE
supports the design, construction, and some preclinical (nonhuman)
testing of the devices. Funding is for research in the following
areas:
- 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).]
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