Nav: Home

Bright lights outdoors may help treat lazy eye in children

June 17, 2019

NEW YORK, June 17, 2019 -- The maturation of visual acuity in both amblyopia and myopia may be closely associated with the development of pathways signaling bright features in the brain, according to research published in the Journal of Neuroscience by SUNY College of Optometry doctoral candidate Carmen Pons Torres and colleagues in the laboratory of distinguished professor Dr. Jose-Manuel Alonso.

While past research indicated that amblyopia, also known as lazy eye, equally affects the brain pathways signaling bright and dark features in an image, Ms. Pons Torres found that amblyopia affects the perception of bright features more than dark features. Her research also shows that, as amblyopia becomes more severe and the images projected in the eye lose detail, bright targets become increasingly difficult to discern. This recent work opens the possibility to treat amblyopia by strengthening weakened brain pathways that signal bright stimuli.

Amblyopia is a developmental problem of the brain that compromises visual acuity in two to five percent of children around the world. Children typically develop amblyopia in one eye and the current treatment is to patch the healthy eye to force the lazy eye to work harder.

Despite being in use for centuries, such patching treatments are problematic. Amblyopia may go undiagnosed for years and patching is less effective in mature brains, there is a high risk of amblyopia recurrence after patching interruption, and low compliance remains prominent as children often do not like to wear the eye patch and tend to remove the treatment when unsupervised.

Previous work from the Alonso lab published in the Journal of Vision by Pons, et al. has shown that low light and optical blur (e.g. reading indoors under dim light) affect the perception of bright targets more than dark targets. Both low light and optical blur are risk factors in myopia, or nearsightedness, which is another developmental problem affecting visual acuity. Another recent study from the Alonso team published in Cell Reports by SUNY Optometry postdoctoral researcher Dr. Reece Mazade, et al. found that these pathways are best stimulated with large bright long-lasting targets, particularly sky patches, which are bright, large and slow-moving.

Both new findings open the door for further exploration of new treatments that use natural visual stimuli more effectively to promote healthier visual behaviors, including wearable devices that monitor vision outdoors.
-end-
Significance Statement from the Original Paper in the Journal of Neuroscience

Amblyopia is a loss of vision that affects 2-5% of children across the world and originates from a deficit in visual cortical circuitry. Current models assume that amblyopia affects similarly ON and OFF visual pathways, which signal light and dark features in visual scenes. Against this current belief, here we demonstrate that amblyopia affects the ON visual pathway more than the OFF, a finding that could have implications for new amblyopia treatments targeted at strengthening a weak ON visual pathway.

Abstract from the Original Paper in the Journal of Neuroscience

Visual information reaches the cerebral cortex through parallel ON and OFF pathways that signal the presence of light and dark stimuli in visual scenes. We have previously demonstrated that optical blur reduces visual salience more for light than dark stimuli because it removes the high spatial frequencies from the stimulus, and low spatial frequencies drive weaker ON than OFF cortical responses. Therefore, we hypothesized that sustained optical blur during brain development should weaken ON cortical pathways more than OFF, increasing the dominance of darks in visual perception. Here we provide support for this hypothesis in humans with anisometropic amblyopia who suffered sustained optical blur early after birth in one of the eyes. In addition, we show that the dark dominance in visual perception also increases in strabismic amblyopes that have their vision to high spatial frequencies reduced by mechanisms not associated with optical blur. Taken together, we show that amblyopia increases visual dark dominance by three to ten times and that the increase in dark dominance is strongly correlated with amblyopia severity. These results can be replicated with a computational model that uses greater luminance/response saturation in ON than OFF pathways and, as a consequence, reduces more ON than OFF cortical responses to stimuli with low spatial frequencies. We conclude that amblyopia affects the ON cortical pathway more than the OFF, a finding that could have implications for future amblyopia treatments.

More information about this study may be downloaded here: https://www.dropbox.com/sh/pmjquunpvi56rlq/AAB5D0HedS45S09zvqLSK7E7a?dl=0

SUNY Optometry

Related Brain Articles:

Study describes changes to structural brain networks after radiotherapy for brain tumors
Researchers compared the thickness of brain cortex in patients with brain tumors before and after radiation therapy was applied and found significant dose-dependent changes in the structural properties of cortical neural networks, at both the local and global level.
Blue Brain team discovers a multi-dimensional universe in brain networks
Using a sophisticated type of mathematics in a way that it has never been used before in neuroscience, a team from the Blue Brain Project has uncovered a universe of multi-dimensional geometrical structures and spaces within the networks of the brain.
New brain mapping tool produces higher resolution data during brain surgery
Researchers have developed a new device to map the brain during surgery and distinguish between healthy and diseased tissues.
Newborn baby brain scans will help scientists track brain development
Scientists have today published ground-breaking scans of newborn babies' brains which researchers from all over the world can download and use to study how the human brain develops.
New test may quickly identify mild traumatic brain injury with underlying brain damage
A new test using peripheral vision reaction time could lead to earlier diagnosis and more effective treatment of mild traumatic brain injury, often referred to as a concussion.
This is your brain on God: Spiritual experiences activate brain reward circuits
Religious and spiritual experiences activate the brain reward circuits in much the same way as love, sex, gambling, drugs and music, report researchers at the University of Utah School of Medicine.
Brain scientists at TU Dresden examine brain networks during short-term task learning
'Practice makes perfect' is a common saying. We all have experienced that the initially effortful implementation of novel tasks is becoming rapidly easier and more fluent after only a few repetitions.
Balancing time & space in the brain: New model holds promise for predicting brain dynamics
A team of scientists has extended the balanced network model to provide deep and testable predictions linking brain circuits to brain activity.
New view of brain development: Striking differences between adult and newborn mouse brain
Spikes in neuronal activity in young mice do not spur corresponding boosts in blood flow -- a discovery that stands in stark contrast to the adult mouse brain.
Map of teenage brain provides evidence of link between antisocial behavior and brain development
The brains of teenagers with serious antisocial behavior problems differ significantly in structure to those of their peers, providing the clearest evidence to date that their behavior stems from changes in brain development in early life, according to new research led by the University of Cambridge and the University of Southampton, in collaboration with the University of Rome Tor Vergata in Italy.

Related Brain Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...