What is Amblyopia

What is amblyopia?

Amblyopia or "lazy eye" is a common vision problem in children and is responsible for vision loss in more children than all other causes combined. Amblyopia is decreased vision of a child that results when one or both eyes send a blurry image to the brain. The brain does not learn to see clearly. Amblyopia may occur even when there is no observable structural abnormality of the eye. If amblyopia is not treated in a timely fashion the vision loss may be permanent into adulthood.

How is amblyopia detected?

A parent or primary care physician may notice either poor vision or strabismus. Primary care physicians routinely screen for amblyopia. Amblyopia is sometimes detected on pre-school vision screening.

What are the types of amblyopia?

The types and causes of amblyopia are: Strabismic amblyopia, deprivation amblyopia, refractive amblyopia, or
a combination of the three. All forms of amblyopia result in reduced vision in the effected eye (s).

What is strabismic amblyopia?

Strabismic amblyopia develops when the eyes are not aligned. When an eye turns in, out, up or down the brain
may "turn off" the eye that is not aligned and the vision subsequently decreases.

What is deprivation amblyopia?

Deprivation amblyopia develops when a cataract or similar condition "deprives" a child's eye of visual input if
not treated very early, vision loss may be severe and may affect both eyes.

What is refractive amblyopia?

Refractive amblyopia occurs when a child has a large or unequal amount of refractive error (need for glasses).
Usually the brain "turns off" the eye that has the larger refractive error. Parents and primary care physicians
may not notice a problem because the eyes are often aligned and the good eye vision is normal. Therefore, this
kind of amblyopia may not be detected unless the vision is tested.

Will glasses help a child with refractive amblyopia see better?

Sometimes, but glasses alone may not correct the vision to 20/20. Glasses are prescribed initially and vision
monitored until there is no further improvement. Any remaining amblyopia is then treated.

Can both eyes have amblyopia?

Yes. When there are equal amounts of high refractive error, both eyes may have poor vision (bilateral
amblyopia) even when wearing glasses. Constant wear of glasses is very important and vision is checked
frequently. Vision typically improves but may take several years.

When and how is amblyopia treated?

Amblyopia is treated during childhood and the earlier the age the better the treatment result. Usually, by the age
of 9-10 years, the visual system is stable and the vision does not improve much with treatment. However, vision
improvement can occur up to 17 years in some cases.

The underlying cause of the amblyopia is treated (correction of refractive error with glasses or contact lenses, removal of cataract, etc) and then vision reassessed. If vision is still reduced, consideration is given to amblyopia treatment. The main forms of treatment are patches and drops. Occlusion treatment involves patching the better seeing to stimulate vision in the poorer seeing eye. The ophthalmologist prescribes the hours per day to patch based on the age of the child and the severity of vision deficit. Follow up exams assess vision in the poorer seeing eye for improvement and in the better seeing eye to confirm no decrease in vision (occlusion amblyopia). In addition to an ophthalmologist an orthoptist may be involved in the assessment and management of amblyopia.