Six previously blind patients detect light, motion, identify objects with retinal prostheses
USC researchers present information on artificial retina May 2 at ARVO 2005
Researchers from the University of Southern California and the Doheny Eye Institutes Doheny Retina Institute will be presenting data on the first six patients implanted with an intraocular retinal prosthesis-more popularly referred to as an artificial retina-developed and manufactured in partnership with Second Sight Medical Products, Inc., of Sylmar, Calif.
According to Mark Humayun, professor of ophthalmology at the Keck School of Medicine and the lead investigator on the project, all six of the previously blind patients have been able to detect light, identify objects in their environment, and even perceive motion after implantation with the epiretinal device.
Data collected as of November of 2004 showed that the six patients-who had been implanted with a single prosthesis in their "worse eye" for between 5 and 33 months-were able to "localize the position of, or count the number of, high contrast objects with 74 to 99 percent accuracy," Humayun says. In addition, they could discriminate simple shapes-i.e., figure out the spatial orientation of a bar or the capital letter L-with 61 to 80 percent accuracy.
The researchers also noted that when there is no electricity running through the device, the subjects do not show any improvement in perceptual acuity, "suggesting that electrical stimulation did not improve the health or function of the retina."
Thus far, participants in the study have been people with little or no sight perception due to the degenerative eye disease retinitis pigmentosa (RP). Ultimately, however, the device is likely to be used for the millions of people suffering from age-related macular degeneration, or AMD, as well. In fact, notes Humayun, there are 25 million people across the globe, including 6 million in the United States alone, who have been blinded, or are severely visually impaired, due to disease like RP and AMD. By 2020, that figure is expected to double, creating a virtual vision-loss epidemic.
Both AMD and RP destroy vision by annihilating the retinal cells that allow light to be translated into recognizable images.
Second Sights intraocular retinal prosthesis is taking the first step to replacing those cells with its device, a 4-by-4 grid of platinum electrodes embedded in silicone rubber. The electrodes are wirelessly stimulated through an external controller hooked up to a head-mounted video camera.
Sarah Huoh | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...