Amblyopia. It’s a term you likely haven’t heard but it is the most frequently diagnosed eye disorder in children. According to the Centers for Disease Control and Prevention (CDC), amblyopia affects 2-3 percent of the population. Amblyopia presents as one eye not being focused the same as the other eye.
“With amblyopia, one eye functions normally while the other eye’s vision is reduced because the brain is favoring one eye, instead of working equally with both eyes,” said Joe Miller, MD, a pediatric ophthalmologist with Banner Children's. “Essentially, the brain doesn’t recognize what the eye with amblyopia is seeing.”
Causes of amblyopia
There is no clear answer as to what causes some children to have amblyopia, but it has been found that certain eye conditions can lead to amblyopia, such as strabismus, cataract or refractive errors.
“The most common cause of amblyopia is strabismus, where the eyes are misaligned and don’t operate together,” said Dr. Miller. “It may look as though one eye is looking in one direction while the other eye is focused in another direction.” Cataracts, which are usually found in older adults, can occur in children and cause hazy and cloudy vision. Nearsightedness, farsightedness and astigmatism – known as refractive errors – can cause amblyopia if they are left untreated.
Some children are more likely to have amblyopia than others, and it can be evident at birth or develop later in childhood. Children with a higher chance of having amblyopia are those who:
- Were born premature
- Had lower than average weight at birth
- Come from a family where there is a history of amblyopia, childhood cataracts, or other eye conditions
- Have developmental disabilities
Diagnosis and treatment of amblyopia
Historically, amblyopia has been difficult to diagnose because it presents in very young children. “A 3- or 4-year-old child isn’t able to read the letters on an eye chart during a vision exam, which has been the traditional method of testing for eye problems,” said Dr. Miller. “In just the last few years, exciting new technology has been developed in the form of a camera with a built-in computer that can take a picture of a child’s eye from as far as one meter away and assess the red glow that comes from the eye to see how the eye is focusing.” According to Dr. Miller, this means children as young as 3 years old can now be assessed, as they don’t need to be able to recognize and read letters on an eye chart.
Because amblyopia is often caused by another eye issue, a physician will likely treat the original eye problem first with glasses, contacts, or potentially surgery. If this treatment doesn’t correct the amblyopia, then the brain will need to be re-trained to use the weaker eye. This is most often accomplished by putting an eye patch over the stronger eye; or using special eye drops in the stronger eye that cause temporary blurred vision, forcing the brain to use the weaker eye. Once corrected, amblyopia can return so these re-training steps may need to be used again for future corrections.
Treating amblyopia in childhood is more effective than waiting until adulthood. If left untreated, the condition can cause permanent vision impairment later in life. “If vision problems are detected in your child, you should take your child to see a licensed eye care provider, such as an ophthalmologist or optometrist, right away,” said Dr. Miller.
Contact Banner Health Pediatric Ophthalmology for more information on amblyopia or to schedule a visit with a licensed eye care provider.