Children with amblyopia may have difficulty visually perceiving spoken words due to impaired visual-auditory integration, according to a study researchers conducted at an academic pediatric ophthalmologic clinic at Ann and Robert H. Lurie Children’s Hospital of Chicago.

Amblyopic kids may not see what you say.

The researchers discovered children with amblyopia were less able than children with 20/20 vision to perceive the McGurk effect—in which a person sees one sound but hears another and yet interprets it as a third sound. 

In the study, researchers compared 24 children with a history of amblyopia in one eye to nine children acting as controls. The researchers played the sound “pa” over a silent video of the sound “ka.”  They asked the children to tell them whether they heard the sound “ka,” “pa” or “ta.” 

“Normal visual-auditory integration produces the perception of hearing a fusion sound ‘ta’,” the authors wrote.

All nine controls perceived the McGurk effect, but only about one-half of the 24 children with amblyopia did. 

“The fact that auditory-visual integration might be compromised reinforces that the decision to treat the child, as well as how aggressively to treat, shouldn’t be based on some arbitrary cut-off for visual acuity values or for age,” says developmental optometrist Leonard Press, of Fair Lawn, NJ.

For some children, amblyopia resolves by five years of age, at which point their auditory-visual perception improves. In this study, all children whose amblyopia had resolved by age five or whose amblyopia had started after that age experienced the McGurk effect. But only about one-fifth of the patients whose amblyopia was unresolved by age five perceived the McGurk effect.

At some point, children with amblyopia will require screening for auditory-visual integration issues, Dr. Press says. “Keep in mind that this is the first study of its kind, and it would have to be replicated before suggesting that all patients with amblyopia routinely undergo central auditory processing evaluations,” he adds.

Burgmeier R, Desai RU, Farner KC, et al. The effect of amblyopia on visual-auditory speech perception: Why mothers may say “Look at me when I’m talking to you.” JAMA Ophthalmol. 2014 Sep 11 [Epub ahead of print].