Sight & Hearing Association

	- Sept 2004 (View past health issues)
Family Eye Care Month - Amblyopia

September is Family Eye Care Month. Mrunalini D. Parvataneni, M.D., a pediatric ophthalmologist with Northwest Eye Clinic in Minnetonka, Minn., and board member of the Sight & Hearing Association, offers her expertise on a common childhood eye condition: amblyopia.

What is Amblyopia?
Amblyopia is the medical term used to refer to poor vision in an eye despite a normally structured eye. The condition affects approximately 2 to 3 out of every 100 children. In this condition, the child does not see as well in one eye as the other. The eye itself is normal but there is an "abnormal visual experience" that leads to this.

What Causes Amblyopia?
There are many causes of amblyopia. The common ones are:

Strabismus (a misalignment of the eyes) - a deviation of one the eyes results in the brain "shutting-off" one eye and resulting in poor vision in the non-preferred eye.
Anisometropia (a difference in the focusing powers between the two eyes) - this is something that is usually present from birth and the difference in focusing results in the brain using the eye that is easier to see with.
Other causes such as cataracts or a severe droopy eyelid.

What Are The Signs of Amblyopia?

Many times, there may be none.
If there is misalignment of the eyes, the parents usually notice and seek attention.
If there is NO misalignment of the eyes, the child sees fine with both eyes open and there may be no signs. Vision screenings are especially important in these cases. A child who does poorly on a vision screen, especially in one eye, should always be evaluated further. It should not be blamed on child fatigue or cooperation until proven otherwise.

Making The Diagnosis
The diagnosis is typically made during an eye examination performed by an ophthalmologist. It is important that the ophthalmologist who sees your child has experience in examining children. Remember, children are NOT little adults.

Treatment
Usually consists of glasses with patching or drops. The purpose of the glasses is to correct the focusing problems and in some situations, to correct the misalignment.

Often, in addition to the glasses, patching or drops are prescribed. This allows for "fogging" of the vision in the strong eye in order to allow the brain to use the weaker eye. This treatment usually takes several months in order to be successful.

Amblyopia treatment requires patience. It took several years for the vision to decrease and so takes time to reverse it.

Occasionally, surgery is recommended to correct the alignment issues. Surgery does not correct the vision. What if my child's amblyopia goes untreated?
Amblyopia can only be treated during the vision development years (until approximately ages 8-10). After this, it typically cannot be treated.

If someone has untreated amblyopia with very poor vision in one eye, that person needs to always protect his/her "good eye". Any damage to the "good eye" may result in visual impairment, as the other eye does not see well.

Resources

American Association for Pediatric Ophthalmology and Strabismus (AAPOS)(http://www.aapos.org)
American Academy of Ophthalmology (AAO) (http://www.aao.org)
National Eye Institute (NEI) (http://www.nei.gov)
Prevent Blindness America (http://www.preventblindness.org)