Aphakia: Symptoms, causes and treatments

Understanding aphakia

When the lens of the eye is missing, this is called aphakia. Aphakia can occur as a result of cataract surgery, trauma or, in rare cases, a birth defect. When an eye’s lens is not present, the result is blurry, out-of-focus vision. 

Aphakia is most commonly treated with the insertion of an intraocular lens (IOL) during lens surgery. Children who are too young for an artificial lens are typically prescribed special contact lenses (or glasses, if they don’t have a lens in either eye).

If a baby or child goes too long without having a lens (natural or artificial) or vision correction of some kind, they may develop amblyopia (lazy eye).

What causes aphakia?

Aphakia can develop in babies, children and adults alike. There are three primary causes of aphakia:

Trauma or injury 

It’s possible to lose the lens of your eye or for it to detach following trauma or injury to the eye or face.

Cataract surgery 

A cataract forms when the eye’s natural lens becomes clouded. In most cases, a cataract is removed during cataract surgery and replaced with an IOL. However, some infants and children may be left without a lens (natural or artificial) after their cataract is removed because their eyes are still growing and developing.

Genetics 

Babies can be born without a lens in one or both of their eyes, but this is very rare. This is called congenital aphakia and it can sometimes be detected via ultrasound. There are two main types: congenital primary aphakia and congenital secondary aphakia.

When aphakia occurs as a birth defect, it’s called congenital primary aphakia (CPA). It may be present alongside other eye abnormalities, including:

• Microphthalmia – This is a birth defect in which one or both eyes are underdeveloped at birth. It occurs in an estimated one out of every 52,000 infants.

• Sclerocornea – This is a congenital abnormality in which the cornea and other front-facing eye structures (like the sclera) do not form completely.

• Aniridia – This is a condition in which there is a complete or partial absence of the iris. This can lead to issues with your pupil, making it difficult for it to dilate (get bigger) or constrict (get smaller) as it adjusts to different lighting.

Babies with CPA do not develop a lens in their eye (or eyes) at any point in vitro. 

Congenital secondary aphakia

Like CPA, congenital secondary aphakia is a birth defect that impacts the development of the eye’s lens. Infants with this condition develop a lens at some point in the womb, but it is reabsorbed before birth. But even after the lens is absorbed, the lens capsule is still present.

How is aphakia diagnosed?

If aphakia may be present at birth or caused by trauma, an eye doctor can use a slit lamp during a comprehensive eye exam to evaluate your eyes. A slit lamp ophthalmoscopy is a type of eye exam that uses a thin, bright stream of light to examine the ocular structures and check if both lenses are present and intact.

While congenital primary aphakia may be detected during a fetal ultrasound, it can be challenging to diagnose because it is so rare.

What are symptoms of aphakia?

Blurry vision is the primary symptom of aphakia because the missing lens prevents the retina from producing a clear image. Additional signs of aphakia include:

• Farsightedness (hyperopia)

• Difficulty shifting focus from nearby objects to those far away and vice versa (also known as difficulty with accommodation)

• Colors appearing faded or muted

• Iridodonesis, a condition in which the iris vibrates or acts unstable during eye movements

What is the treatment of aphakia?

Treatment for aphakia usually depends on the age of the patient. The most common treatment for aphakia is lens surgery, where the missing lens is replaced with an artificial intraocular lens (IOL). During this procedure, an IOL is implanted to take the place of the absent natural lens. 

However, newborns and young children are susceptible to more complications through surgery, so IOLs aren’t always an option for younger patients. Until they are old enough for surgery, a child born with aphakia may be better suited for vision correction using special glasses or contacts. This is called external optical correction.

Glasses are typically prescribed for patients who have aphakia in both eyes rather than just one. However, contact lenses may be the preferred treatment even in cases of bilateral aphakia because eyeglasses can cause: 

• Vision distortion

• A different visual acuity in each eye

• Prismatic effects

Contact lenses do not have such a high risk of side effects.

Can aphakia lead to complications?

Aphakia can lead to complications if it is left untreated. Babies and children are especially prone to vision difficulties if they have aphakia and do not receive surgery or optical correction. This is because aphakia can lead to amblyopia, which may be irreversible.

While rare, some complications that have been associated with aphakia following corrective surgery are:

• Aphakic glaucoma

• Pseudophakic glaucoma

When should I see a doctor?

If you notice any changes in your vision, or it seems like your infant has difficulty seeing, you should contact your eye doctor or pediatrician. Aphakia and other serious conditions require assessment and treatment as soon as possible. 

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Page published on Thursday, April 21, 2022

Page updated on Wednesday, April 20, 2022

Medically reviewed on Tuesday, February 22, 2022