Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Retinal prosthesis trial completes first phase of testing

09.05.2003


One-year results presented at annual ophthalmology meeting



Researchers from the Keck School of Medicine of the University of Southern California, its Doheny Retina Institute and Second Sight, LLC, are reporting on the initial results of their groundbreaking, FDA-approved feasibility trial of an intraocular retinal prosthesis that appears to be able to restore some degree of sight to the blind.

"We have successfully completed enrollment and implantation of three patients in the trial," says Mark Humayun, M.D., professor of ophthalmology at the Keck School. "And we have found that the devices are indeed electrically conducting, and can be used by the patients to detect light or even to distinguish between objects such as a cup or plate in forced choice tests conducted with one patient so far."


The results are being presented at the Retinal Prosthesis I session of the annual meeting of the Association for Research in Vision and Ophthalmology, or ARVO, being held this week in Fort Lauderdale, Fla. Humayun, who is moderator of the session, is also presenting a paper detailing the results of the trial. In addition, he and his group from USC’s Doheny Retina Institute displayed six posters in sessions throughout the week. (Posters are embargoed until the time of their presentation.)

The microelectronic retinal prosthesis used in this first phase of the trial is intended to stand in for the damaged retinal cells in people suffering from such blinding diseases as retinitis pigmentosa and macular degeneration. The implant measures 4 millimeters by 5 millimeters, and is studded with 16 electrodes in a 4-by-4 array. The device has been developed by Sylmar, Calif.-based Second Sight, LLC: www.2-sight.com

The first participant in the trial underwent surgery to receive the implant in February of 2002. Patient #2 received the implant in July 2002, and patient #3 underwent surgery in March of 2003.

The retinal prosthesis-a sliver of silicone and platinum that is often incorrectly referred to as an ’eye chip’-is attached to and sits atop the retina. It works by electrically stimulating the remaining healthy retinal cells via the array of electrodes; the retinal cells, in turn, pass on the visual information to the brain via the optic nerve.

Initial tests in the three implanted patients have shown that they can perceive light on each of the 16 electrodes. Testing conducted so far in some of the patients with the microelectronic implant revealed that they were capable of detecting when a light is turned on or off, describing the motion of an object, and even counting discrete objects.

The first tests of the prosthesis in all three patients involved computer-generated points of light sent directly to the implant, says Humayun. Over time, they were ’graduated’ to images received by an external video camera. These images are sent to the intraocular electrode array attached to the retina via a receiver that is implanted behind the patient’s ear during the implant surgery. The signal is then recreated by stimulating the appropriate electrodes in the prosthesis.

Testing on the three patients is ongoing, says Humayun. "We plan in the near future to look at how useful the prosthesis can be in activities of daily living," he notes.


In addition to Humayun, the researchers involved in this work include Keck School researchers Eugene de Juan Jr., M.D., Douglas Yanai, M.D., Manjunatha Mahadevappa, Ph.D., Gretchen van Boemel, Ph.D., Gildo Fujii, M.D., and James Weiland, Ph.D., as well as Robert Greenberg, M.D., Ph.D., president of Second Sight, LLC, and other Second Sight scientists.

The National Institutes of Health/National Eye Institute and Second Sight, LLC, provided funding to support the research and development of the retinal prosthesis implanted in this trial. The National Science Foundation, the Department of Energy, the Office of Naval Research, the Whitaker Foundation, The Foundation Fighting Blindness, the Defense Advanced Research Projects Agency and Second Sight, LLC, have provided other funding toward the development of a retinal prosthesis.

For copies of abstracts online, go to www.arvo.org and click on the annual meeting link. Posters relating to this paper were or will be displayed in poster sessions 5056 (B715), 5059 (B718), 5060 (B719), 5079 (B738), 5081 (B740), and 5085 (B744); posters are embargoed until the time of their presentation.

Jon Weiner | EurekAlert!
Further information:
http://www.arvo.org

More articles from Health and Medicine:

nachricht Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>