Amblyopia

What is amblyopia?

Amblyopia means a decrease in fine vision or visual acuity, also known as sharpness. It happens when the brain does not fully develop the vision in the eye. Amblyopia usually happens in only one eye, but it can happen in both eyes. It is sometimes called "lazy eye".

Causes of amblyopia

Amblyopia can be caused by any condition or illness that makes the eye blur an image or makes the brain prefer one eye. Common causes include:

• strabismus (when one eye is turned in a different direction than the other eye)
• anisometropia (when one eye focuses differently than the other)
• uncorrected refractive error (when one or both eyes need glasses to see properly)
• cataract (clouding of the eye's lens)
• severe ptosis (droopy eyelids)
• heredity (when a child inherits amblyopia from parents with strabismus)
• premature birth
• any disease that affects the eye

Children under nine are at the greatest risk

Children under nine years of age are at the highest risk for amblyopia. At this age, your child's vision is still developing. Generally, the younger the child, the greater the risk.

Treatment of amblyopia

Each child's amblyopia is different. Your child's treatment will depend on their age, and the cause and severity of the amblyopia. Treatment may include eyeglasses, patching, eye drops and/or surgery. Your child’s eye doctor will explain the best treatment for your child.

Eyeglasses

Your child may need eyeglasses to improve their vision. These help the eyes work together and help focus images for both eyes. Eyeglasses will only work if your child wears them all the time when they are awake.

Patching

Blocking the vision of your child's stronger eye with a patch helps to strengthen their lazy eye.

Your child’s health-care provider will explain how often to apply the patch and how long your child will need it. The health-care provider will need to check your child often to see if the treatment is working.

Eye drops

In some cases, your child's health-care provider may prescribe special drops to blur the vision in the stronger eye. This makes the lazy eye work harder. It is very important to put in the eye drops correctly.

Surgery

Although surgery alone does not correct amblyopia, it may be needed to treat the underlying cause. Your child may need surgery when amblyopia happens along with:

• strabismus
• cataract
• ptosis
• other diseases of the eye

If surgery is needed, your child's eye doctor will tell you what will happen. Eyeglasses, patching and/or eye drops may still be required after surgery.

If you have any questions or concerns, please call the health-care provider who saw your child.

Prevention of amblyopia

You can reduce the risk of severe amblyopia with regular eye testing, by following the treatment given by your child’s health-care provider (such as glasses, patching or eye drops) and attending all your follow-up visits.

Complications of amblyopia

If left untreated, amblyopia may cause vision to decrease more in the affected eye(s). Treatment can be less effective in older children or in children with severe amblyopia. Decreased depth perception and new or worsening strabismus can also result from untreated amblyopia.

Long-term outcomes

Treatment outcomes are different for everyone with amblyopia. Outcomes depend on the cause of amblyopia and the age of the patient when they are treated. Following treatment instructions and attending follow-up visits is important to know how a patient’s vision is responding to their treatment and so your child’s health-care provider can adjust treatment as needed.

At SickKids

For more information, please call 416-813-6838 and a health-care provider can help answer your questions.