Persistent Pupillary Membrane

What is persistent pupillary membrane?

Persistent pupillary membrane is the medical term for extra tissue that covers some or all of an infant’s pupil. It’s a type of congenital eye condition — an issue that affects a child’s eyes from birth. It happens when the membrane that covers a fetus’s eyes while it’s developing doesn’t dissolve like it should before birth.

If your child has persistent pupillary membrane, it might look like strands or sections of their iris (the colored part of their eye) are covering their pupil (the black center of their eye). It can look like thin strings or a web-like net.

Most babies born with persistent pupillary membrane have no symptoms. Usually, the membrane breaks apart and goes away within a year. But if the membrane remains past one year, some children need surgery to remove it to prevent complications with their eyes and vision.

Visit an eye care specialist as soon as you notice any changes or symptoms in your child’s eyes.

How does persistent pupillary membrane affect my child’s eyes?

Persistent pupillary membrane probably won’t affect your child’s eyes. Most of the time, the strands of membrane are so small (or break apart so quickly) that you’ll never notice them. If the membrane has thicker strands or covers a big portion of your child’s pupil, it might affect their vision.

Kids with persistent pupillary membrane that doesn’t go away on its own are more likely to develop amblyopia (lazy eye). Amblyopia happens when one of a child’s eyes has blurred vision, and the other has clear vision. Their brain ignores the blurry eye and only uses the eye with clear vision. Fortunately, it’s very treatable. An eye care specialist will treat the persistent pupillary membrane to prevent amblyopia.

It’s rare for persistent pupillary membrane to cause severe complications. But some children with untreated persistent pupillary membrane have an increased risk for health conditions that affect their eyes, including:

• Glaucoma.
• Cataracts.
• Ectopia lentis.

Who does persistent pupillary membrane affect?

Any baby can be born with persistent pupillary membrane. It’s extremely common. More than 90% of babies are born with some amount of persistent pupillary membrane. Children born prematurely are more likely to have persistent pupillary membrane.

Around 20% of adults have some amount of persistent pupillary membrane in one of their eyes.

What are the symptoms?

Persistent pupillary membrane doesn’t usually cause any symptoms. Many parents never know their children were born with it.

If your child has symptoms, they’ll probably have refractive errors in their affected eye that make their vision blurry.

What causes persistent pupillary membrane?

When a fetus is developing during pregnancy, a layer of blood vessels completely covers the front of its eyes. This membrane (the anterior tunica vasculosa lentis) protects the eyes and supplies them with the blood they need to keep developing.

Usually, the membrane shrinks and disappears six to eight months into a pregnancy. If some of the tunica vasculosa lentis doesn’t dissolve by the time your child is born, they’ll have persistent pupillary membrane.

How is persistent pupillary membrane diagnosed?

An eye care specialist will diagnose persistent pupillary membrane. They’ll use a slit lamp exam to look at your child’s eyes (including inside them). Your child will probably need a visual acuity test to confirm how much the persistent pupillary membrane affects their vision.

Your eye care specialist might diagnose persistent pupillary membrane during your child’s regular eye exam before you notice anything different about their eyes.

How is persistent pupillary membrane treated?

Persistent pupillary membrane usually doesn’t need treatment. The remaining membrane strands typically break apart and go away on their own within a year of a child’s birth.

If the persistent pupillary membrane is made of thicker-than-usual strands or is covering a large portion of your child’s eye, they might need treatment, including:

• Corrective lenses:Eyeglasses or contact lenses can correct any refractive errors.
• Medication:Mydriatics (eye drops) that dilate your child’s pupil can help create enough space around the membrane for them to see more clearly.
• Wearing an eyepatch: Wearing a patch on their unaffected eye will encourage your child’s brain to use the eye with persistent pupillary membrane and prevent amblyopia.
• Surgery: It’s rare to need surgery for persistent pupillary membrane. Your eye care specialist will tell you which type of surgery your child needs and how long it’ll take them to recover.

How can I prevent persistent pupillary membrane?

You can’t prevent your child from being born with persistent pupillary membrane. It happens randomly — it’s not a genetic disorder that healthcare providers can diagnose ahead of time.

What can I expect if my child has persistent pupillary membrane?

Persistent pupillary membrane shouldn’t have any long-term effects on your child’s eyes or vision. Even if they need treatment, their affected eye should develop normally and stay healthy.

Your child might need follow-up eye exams. Your eye care specialist will monitor the persistent pupillary membrane and watch for any other changes in your child’s eyes or vision.

How often should I have my child’s eyes examined?

Having your child’s eyes and vision checked regularly can help your eye care specialist identify problems right away. An eye care specialist should check your child’s eyes during their first year of life, and then every one to two years after that.

What questions should I ask my doctor?

• Will my child need treatment for persistent pupillary membrane?
• Do they have any other issues or complications?
• How often will my child need eye exams?

A note from Cleveland Clinic

Persistent pupillary membrane can look scary, but it’s almost always a temporary, harmless condition that goes away on its own. Once the membrane finishes dissolving, your child’s eyes should be healthy and develop normally.

Visit an eye care specialist as soon as you notice any changes in your child’s eyes. Even though persistent pupillary membrane doesn’t usually need treatment, it’s important to have a healthcare provider examine your child’s eyes to make sure they don’t have any other symptoms or issues.