Refractive Amblyopia: Everything You Need to Know

Amblyopia, or lazy eye, is a medical condition that makes it difficult to see clearly through one eye because of abnormal development of that eye during childhood. The condition results in a wandering eye. 

What causes of amblyopia is a refractive error in the bad eye, either nearsightedness, farsightedness or astigmatism.

Intro

Amblyopia is a medical condition that makes it difficult to see clearly through one eye because of abnormal development of that eye during childhood. The condition results in a wandering eye or lazy eye. 

Individuals with lazy eye depend heavily on their normal eye to see, while the weaker (amblyopic) eye will worsen over time from lack of stimulation from the brain. There are three types of amblyopia:

• Refractive amblyopia
• Strabismic amblyopia
• Deprivation amblyopia

Refractive amblyopia is the most common type of amblyopia, especially among young children. Refractive errors cause this type, and the errors make it difficult for light to get focused correctly on your eye, making objects appear blurry.

The two types of refractive amblyopia that can affect your eyes include:

• Isoametropic amblyopia
• Anisometropic amblyopia

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Causes

Refractive amblyopia usually occurs because of one of several refractive errors. Among them:

• Nearsightedness, where you only see nearby objects clearly.
• Farsightedness, nearby objects appear blurry.
• Astigmatism, the irregular shape of your eye’s lens.

The lens is the clear part that helps focus an object’s light on your eye. Depending on how they affect your eyes, errors will cause either anisometropic or isoametropic refractive amblyopia. 

Anisometropic Amblyopia

With this condition, one eye is significantly more affected by refractive errors than the other, so your eyes will not focus on objects equally. It occurs primarily because of hyperopia (farsightedness) but can also happen because of unequal amounts of myopia (anisomyopia) between your eyes.

Isoametropic Amblyopia

In this case, your eyes have the same high levels of refractive errors. Isoametropic amblyopia occurs primarily if your eyes are affected by high levels of farsightedness.

Symptoms of Refractive Amblyopia

Refractive amblyopia rarely presents with symptoms. Some children might not even know they have it until the doctor examines their eyes. But the symptoms will be more or less the same as that of the other types of amblyopia. They are:

• Depth perception difficulty in viewing objects from three dimensions. You cannot judge the distance of an object accurately.
• A head tilt, with the positioning of the head is one particular angled position so that you can see clearly.
• Eyes turn in or out
• Convergence insufficiency: , making your eyes unable to collaborate when focusing on an object
• Poor vision in the affected eye

Risk Factors

Having refractive errors usually increases your chances of getting refractive amblyopia. Some other non-eye related risk factors also increase the risk, including:

• Smoking during pregnancy
• Premature birth
• Children with an APGAR score of less than 7
• Refractive amblyopia family history

Treatment Options

To be successful, treatment of refractive amblyopia must begin early, especially in children. Take your child to the eye doctor immediately when you suspect that they have amblyopia to avoid complications.

Children are more responsive to treatment options of eye patches, eye drops and eyeglasses.

Eye Patches

The standard way of treating refractive amblyopia is using an eye patch. Covering the good eye with a patch will force the brain to interpret images from the amblyopic eye, strengthening the connection. Eye doctors advise that you wear the patch for at least two hours a day.

Atropine Eye Drops

The eye doctor can use the drug Atropine as an alternative to an eye patch. Atropine reduces the abilities of the good eye to focus on near objects. Both eyes will have a certain level of refractive error, making the brain stop favoring one eye over the other.

The drug is more convenient than eye patches. However, the drug has its drawbacks because it may not work for people who have resistance to eye drops. It can also have some side effects, such as light sensitivity.

Eyeglasses

Eyeglasses are another commonly used method for correcting refractive amblyopia. Glasses work by correcting the refractive errors causing amblyopia. 

Complications

Leaving refractive amblyopia untreated leads to irreversible complications such as:

• Children with learning and reading difficulties
• Problems related to visual function, such as visual acuity
• It can cause blindness in some instances
• Serve strabismus (crossing of eyes)

Refractive Amblyopia in Adults vs. Children

Refractive amblyopia is usually associated with young children. However, there are some reported cases among adults as well. Adults develop the condition because of a failure to correct it when they were young. 

Unlike in children, refractive amblyopia causes a permanent reduction in vision among adults. Adults also respond differently to children when using refractive amblyopia treatments. Vision therapy is the best lazy eye treatment for adults.

FAQs

Can refractive amblyopia be corrected?

Yes. There are different treatment methods for refractive amblyopia. These procedures aim at correcting the refractive errors causing amblyopia. The standard treatment methods are eye patches, eyeglasses, and atropine eye drops. 

Is refractive amblyopia a disability? 

Not necessarily. If you notice that you have refractive amblyopia and treat it promptly, you will avoid any vision-related problems. Notably, if you leave it untreated, some visual disabilities such as blindness can result.

Can refractive amblyopia get worse?

Yes, it can get worse. Refractive amblyopia is less severe, and you may not notice it during your childhood days. But if left untreated, it can get worse, causing further complications to your eyes.

References

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7. Anisometropic Amblyopia. (December 2021). American Academy of Ophthalmology.

8. Isoametropic amblyopia due to high hyperopia in children. (August 2004). Journal of the American Association for Pediatric Ophthalmology & Strabismus.

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