What is Amblyopia?

Amblyopia is decreased vision in one or both eyes due to abnormal development of vision in infancy or childhood. In amblyopia, the eye may not appear to have an obvious problem. Vision loss occurs because nerve pathways between the brain and the eye are not properly stimulated. The brain “learns” to see only blurry images with the amblyopic eye even when glasses are used. As a result, the brain favors one eye, usually due to poor vision in the other eye. Another word for amblyopia is often “lazy eye.” It is the leading cause of vision loss among children.

What causes Amblyopia?

Normal vision develops during the first few years of life. Infants have very poor vision at birth. However, as they use their eyes, the vision improves because the vision centers in the brain are developing. If infants are not able to use their eyes for whatever reason, the vision centers do not develop properly and the vision is decreased despite the normal appearance of the eyes.

The most common cause is refractive error in one or both eyes that is not corrected early in childhood resulting in poor vision in the affected eye(s).  This is called refractive amblyopia. Another common cause is strabismus or eye misalignment. This is called strabismic amblyopia.

On rare occasion, there is a structural anomaly that impairs the visual function like a droopy eyelid or opacity in the visual axis like a cataract or corneal scar. This is called deprivation amblyopia.

Multiple causative factors can coexist.

How is Amblyopia treated?

One of the most important treatments of amblyopia is correcting the refractive error with consistent use of glasses or contact lenses. Other mainstays of amblyopia treatment include forcing the child to use the weaker eye by patching the better eye or blurring the better-seeing eye with eye drops such as atropine. If the visual axis of the eye is obstructed by a droopy lid or an opacity such as a cataract or a corneal scar, surgery may be needed for treatment of the amblyopia.

Can Surgery Be Performed to Treat Amblyopia?

There is no surgery to improve the vision for amblyopia. Surgery can be performed to straighten misaligned eyes but the goal of the surgery is to make the eyes straight and enable the eyes to work together as a team. Children with strabismic amblyopia still need close monitoring and treatment for the amblyopia with glasses, patching, and/or eye drops.

Source: American Association of Pediatric Ophthalmology and Strabismus