Abnormal vision in childhood can affect brain functions

October 12, 2018

A research team has discovered that abnormal vision in childhood can affect the development of higher-level brain areas responsible for things such as attention.

The researchers from the University of Waterloo, University of British Columbia, and the University of Auckland uncovered differences in how the brain processes visual information in patients with various types of lazy eye. In doing so, they are the first to demonstrate that the brain can divert attention away from a lazy eye when both eyes are open.

"Current treatments for lazy eye primarily target the early stages of visual processing within the brain," said Ben Thompson, a professor in Waterloo's School of Optometry and Vision Science."The results from this study show us that new treatments should also target higher-level processes such as attention."

Lazy eye, known as amblyopia, is a loss of vision that originates in the brain, typically when a child develops an eye turn (strabismic type) or a substantial difference in refractive error between the eyes (anisometropic type). The unequal input causes the brain to ignore information from the weaker eye during brain development. Conventionally, eyecare practitioners treated the different types of lazy eye similarly, primarily because the visual impairments experienced appeared to be the same.

In this study lead researcher, Amy Chow, and her colleagues asked patients to pay attention to a specific set of dots among a group of distracting dots, all moving on a computer screen. However, the tracked dots were only visible in one eye (the weaker eye) while the distracting dots were visible only to the other eye (the stronger eye).

For people with normal vision as well as those with anisometropic amblyopia, showing different images between the two eyes didn't matter. Both groups were able to overcome the distracting interference and track the dots successfully. Patients with strabismic amblyopia, on the other hand, were unable to direct their attention to the target dots when they were visible to only the weaker eye.

"One of the underlying reasons why some people with lazy eye have poor vision comes down to how the brain suppresses an eye," said Chow, a PhD student at the School of Optometry and Vision Science at Waterloo. "The poorer-seeing eye is open, the retina is healthy and sending information through to the brain, yet that information does not reach conscious awareness as the brain chooses not to use it."

About thirty-five thousand Canadians - one per cent of the population - have strabismic amblyopia. The condition can be corrected in childhood, but treatment efficacy can be highly variable. These findings are a stepping stone in developing better treatments of lazy eye.
-end-
Their paper, Dichoptic Attentive Motion Tracking is Biased Toward the Nonamblyopic Eye in Strabismic Amblyopia, appears this month in a special issue of the journal Investigative Ophthalmology and Visual Science. The project was supported by the Natural Sciences and Engineering Research Council of Canada.

University of Waterloo

Related Brain Articles from Brightsurf:

Glioblastoma nanomedicine crosses into brain in mice, eradicates recurring brain cancer
A new synthetic protein nanoparticle capable of slipping past the nearly impermeable blood-brain barrier in mice could deliver cancer-killing drugs directly to malignant brain tumors, new research from the University of Michigan shows.

Children with asymptomatic brain bleeds as newborns show normal brain development at age 2
A study by UNC researchers finds that neurodevelopmental scores and gray matter volumes at age two years did not differ between children who had MRI-confirmed asymptomatic subdural hemorrhages when they were neonates, compared to children with no history of subdural hemorrhage.

New model of human brain 'conversations' could inform research on brain disease, cognition
A team of Indiana University neuroscientists has built a new model of human brain networks that sheds light on how the brain functions.

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.

Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.

An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.

Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.

Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.

Read More: Brain News and Brain Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.