Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Lazy eye' treatment shows promise in adults

04.03.2008
New data, based on a finding first reported in 2006, suggest a simple and effective therapy for amblyopia. Clinical use will depend on optometry community
New evidence from a laboratory study and a pilot clinical trial confirms the promise of a simple treatment for amblyopia, or “lazy eye,” according to researchers from the U.S. and China.

The treatment was effective on 20-year-old subjects. Amblyopia was considered mostly irreversible after age eight.

Many amblyopes, especially in developing countries, are diagnosed too late for conventional treatment with an eye patch. The disorder affects about nine million people in the U.S. alone.

Results from the laboratory study will be published online the week of Mar. 3 in PNAS Early Edition.

Patients seeking treatment will need to wait for eye doctors to adopt the non-surgical procedure in their clinics, said Zhong-Lin Lu, the University of Southern California neuroscientist who led the research group.

“I would be very happy to have some clinicians use the procedure to treat patients. It will take some time for them to be convinced,” Lu said.

“We also have a lot of research to do to make the procedure better.”

In a pilot clinical trial at a Beijing hospital in 2007, 28 out of 30 patients showed dramatic gains after a 10-day course of treatment, Lu said.

“After training, they start to use both eyes. Some people got to 20/20. By clinical standards, they’re completely normal. They’re not amblyopes anymore.”

The gains averaged two to three lines on a standard eye chart. Previous studies by Lu’s group found that the improvement is long-lasting, with 90 percent of vision gain retained after at least a year.

“This is a brilliant study that addresses a very important issue,” said Dennis Levi, dean of optometry at the University of California, Berkeley. Levi was not involved in the study.

“The results have important implications for the treatment of amblyopia and possibly other clinical conditions.”

The PNAS study shows that the benefit of the training protocol – which involves a very simple visual task – goes far beyond the task itself. Amblyopes trained on just one task improved their overall vision, Lu said.

The improvement was much greater for amblyopes than for normal subjects, Lu added.

“For amblyopes, the neural wiring is messed up. Any improvement you can give to the system may have much larger impacts on the system than for normals,” he said.

The Lu group’s findings also have major theoretical implications. The assumption of incurability for amblyopia rested on the notion of “critical period”: that the visual system loses its plasticity and ability to change after a certain age.

The theory of critical period arose in part from experiments on the visual system of animals by David Hubel and Torsten Wiesel of Harvard Medical School, who shared the 1981 Nobel Prize in Medicine with Roger Sperry of Caltech.

“This is a challenge to the idea of critical period,” Lu said. “The system is much more plastic than the idea of critical period implies. The fact that we can drastically change people’s vision at age 20 says something.”

A critical period still exists for certain functions, Lu added, but it might be more limited than previously thought.

“Amblyopia is a great model to re-examine the notion of critical period,” Lu said.

The first study by Lu’s group on the plasticity of amblyopic brains was published in the journal Vision Research in 2006 and attracted wide media attention.

Since then, Lu has received hundreds of emails from adult amblyopes who had assumed they were beyond help.

Berkeley’s Levi cautioned that the clinical usefulness of perceptual learning, as Lu calls his treatment, remains a “sixty-four thousand dollar question.”

“It's clear that perceptual learning in a lab setting is effective,” Levi said. “However, ultimately it needs to be adopted by clinicians and that will probably require multi-center clinical trials.”

Carl Marziali | EurekAlert!
Further information:
http://www.usc.edu

More articles from Studies and Analyses:

nachricht Deep Brain Stimulation Provides Sustained Relief for Severe Depression
19.03.2019 | Universitätsklinikum Freiburg

nachricht AI study of risk factors in type 1 diabetes
06.03.2019 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Levitating objects with light

19.03.2019 | Physics and Astronomy

New technique for in-cell distance determination

19.03.2019 | Life Sciences

Stellar cartography

19.03.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>