A world as blurry as ripples on a reflecting pool can look perfectly normal to a nearsighted child who thinks that’s how everyone sees.
Other eye disorders can be invisible to parents, and difficult for health care providers to see. Without a visible eye shift, even amblyopia can be overlooked and precious time lost while vision is developing in the young brain. Children whose eyes test 20/20 may still have trouble coordinating their eyes well enough to focus and track words across the page.
“Children aren’t always able to describe what they are seeing or answer questions as well as adults, but we can do full eye exams objectively using equipment and techniques developed for pediatric patients,” Lee said.
“We sometimes see very young babies who have cataracts or systemic diseases that affect vision,” Weise said. “The cataracts may not be obvious or that common, but when problems like these occur, it’s important to identify and treat them early so visual development in the brain isn’t affected by deprivation.”
Amblyopia is another pediatric eye disorder that conventional wisdom says must be treated early to be effective. However, recent research is showing encouraging results in treating older children whose condition was diagnosed later.
“Visual development within the brain occurs primarily between birth and age seven, so that is why early diagnosis is so important in treating amblyopia,” Weise said. “That doesn’t mean it’s too late to help older children. Research through the Pediatric Eye Disease Investigation Group (PEDIG) is showing improvement from interventions in children up to age 17.”
“Especially in cases where an eye shift isn’t visible, amblyopia may not be diagnosed till later,” Weise said. “It can develop when one eye is very near sighted or far sighted. The stronger eye wins, and the brain turns off the weaker eye. If something happens to the stronger eye, that would leave the patient without vision. The goal of treatment is to preserve as much function as possible in the weaker eye.”
Patching the good eye to retrain the weak eye has been the usual mode of treatment, though not always an easy treatment in the case of younger children who may be inclined to pull off the patch the moment the parent’s back is turned.
“It doesn’t make sense to a small child,” Weise said. “They can see perfectly well with the strong eye until the patch goes over it, and then they may get frustrated and want to take it off. When we can’t get good compliance with patching, we can use atropine drops administered by the parent to blur the dominant eye. Study results indicate atropine is equally effective, but there is still the issue of getting the drops into the eye. Blurring can also last a while and make scheduling around homework and other activities difficult. So we started looking at how many hours a day and how many days a week patching or atropine drops were needed to be effective.”
The PEDIG research showed that retraining the weaker eye required fewer hours a day than was previously thought, and that patching or using atropine drops on weekends could also work, leaving the eyes free for homework and after school activities during the week.
“Diagnosing the disorder and beginning treatment are the most important factors,” Weise said. “Screenings are helpful in detecting amblyopia, but children are very good at cheating. They have a tendency to turn their head and peek with the other eye. The most objective way to identify amblyopia is with an eye exam.”
Lee frequently sees children whose vision may initially appear to be normal, at least in the 20/20 sense. However, difficulty in reading and complaints of headaches or eye pain frequently bring patients to her office for a second look at what might be causing problems.
“Around five percent of our patients have difficulty with either focusing or eye teaming and coordination,” Lee said. “A routine exam checks for whether a child needs glasses, but not all exams do the kind of binocular vision workup necessary to identify a convergence insufficiency or accommodative insufficiency problem. We often receive referrals when these issues are suspected.
“We have a questionnaire that usually gives us a good indication of where to start looking. Do the children tend to lose their place when reading, or see double when reading? Do they say they don’t like to read or avoid reading, or say their eyes hurt? The problem may be that eye muscles aren’t strong enough to focus up close. When we identify a deficit, we use exercises to retrain the eyes.”
Both Weise and Lee are active in pediatric eye research through PEDIG. One NIH study currently recruiting will look at home-based computer therapy to determine whether it can help children with eye convergence problems.
“The visual stress of close-up work has increased with more people, including children, spending more time on computers. That makes good close-up vision even more important, and we’re hoping computers can be effective tools in helping children see well.”
Considering the range of eye disorders that may not be immediately apparent, and the fact that the best time to correct a problem is while the visual centers of the young brain are still developing, when is the best time for an eye exam?
“There is a lot of discussion about timing, but the American Optometric Association suggests an eye exam at six months, age two or three, and just before entering school,” Lee said.
“Definitely before school,” Weise agreed. “And children with diabetes and other systemic diseases will need to be watched more closely, with annual exams to check for signs of potential problems.”
