What is aniridia?
Aniridia is a serious and rare eye disorder in which the iris is partly or completely gone. It usually happens in both eyes. The pupil is abnormally large and may be oddly shaped. Aniridia means “lack of an iris.” It can also affect the eye’s cornea, anterior chamber, lens, retina, and optic nerve. Some of these problems are present from birth. Others may happen later in life.
The iris is the circular, colored structure of your eye. It controls the size of your pupil and the amount of light that enters your eye. Problems with other parts of your eye may cause issues that are more significant than aniridia.
Usually, aniridia happens on its own. In some cases, aniridia is one of several syndromes that are associated with other symptoms. About an equal number of people of both sexes are affected. Aniridia may be more common in certain parts of the world.
What causes aniridia?
Researchers think many cases of aniridia happen because of a problem with a gene known as PAX6. PAX6 is part of the genetic information you pass to your children. This gene is crucial for eye health and development. If PAX6 doesn’t work right, your eyes may not develop properly. This may cause aniridia.
Who is at risk for aniridia?
If someone in your family has aniridia, you have an increased risk for it. Most forms of aniridia are autosomal dominant. That means that a child of a person with aniridia has a 50% chance of having it. However, some people who have aniridia don’t have any family with the condition.
What are the symptoms of aniridia?
Aniridia can cause a variety of symptoms, such as:
- Poor vision (not always present)
- Increased sensitivity to light
- Nystagmus (involuntary eye movements)
- Strabismus (eyes not lining up)
Usually, aniridia affects only your eyes. However, some people have aniridia along with other symptoms. The most common are Wilms tumor (tumor of the kidney), genitourinary problems, and mental retardation. Together with aniridia these are known as WAGR. In rare cases, aniridia can happen with Gillespie syndrome. This is a rare syndrome that affects the eyes and the brain. People with disorder also have mental retardation and balance problems.
How is aniridia diagnosed?
Diagnosis of aniridia usually happens early in life. To diagnose the condition, a healthcare provider will ask about your child’s medical history. He or she will also have a physical exam. This includes an eye exam. The healthcare provider may be able to see a small rim of the iris when looking at your child’s eye.
In some cases, a healthcare provider might order tests. These are done to get information about the genes involved.
How is aniridia treated?
Children with aniridia need regular eye exams to check their vision. Your child’s healthcare provider will also need to carefully watch for complications of aniridia. These may include cataracts and glaucoma. These problems may need their own treatment.
Many children with aniridia need special glasses. These are to protect their eyes from sunlight and injury. Glasses can also help correct any loss of vision sharpness. Some people may be able to wear a special type of painted soft contact lens. These can help to reduce glare, sharpen vision, and improve the appearance of the eyes.
An eye healthcare provider may also treat aniridia by replacing the iris with an artificial iris. This is done with surgery.
What are the complications of aniridia?
Aniridia can cause severe problems, many of which are very common. These may happen soon after birth. Or they may happen later in life. Some of these health conditions are also common in older people who don’t have aniridia. But with aniridia, they happen at an earlier age. Complications can include:
- Aniridia-associated keratopathy. This is when the cornea becomes more opaque. It makes vision worse.
- Glaucoma. This is excess fluid buildup in the front part of the eye. It happens most often in adolescent children with aniridia.
- Cataract. This is clouding of the lenses of the eyes. This can impair vision.
- Problems with the optic nerve. This nerve sends visual information to the brain.
- Tearing or detachment of the retina. The retina is the light-sensitive region on the back of the eye.
These complications can cause a number of symptoms, including:
- Blurred vision
- Blindness in part of the field of vision
- Flashes of light in the eye
- Pain in the eye
Your child might need medicated eye drops or surgery to treat these complications.
How to manage aniridia
Most children with aniridia will be able to attend a normal school. However, your child may need extra support in the classroom to cope with his or her visual issues.
You may find a support group helpful. Aniridia Foundational International is a support group for people with aniridia and their family. You can contact the foundation at www.aniridia.net.
When should I call my healthcare provider?
Call 911 right away if your child has sudden vision loss or sudden eye pain.
Key points about aniridia
Aniridia is a serious and rare eye disorder in which the iris is partially or completely absent, generally in both eyes. Aniridia can also affect the eye’s cornea, anterior chamber, lens, retina, and optic nerve.
- Your child may have certain problems from birth, like increased light sensitivity.
- Other eye problems may develop later, like cataracts or glaucoma.
- Your child may need to wear special contact lenses or glasses to protect his or her eyes.
- Your child will need regular eye checkups. Your eye healthcare provider will check visual sharpness and monitor for complications.
- Your child might need surgery to treat aniridia or an eye complication from aniridia.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure
March 22, 2017
Haupert, Christopher L., MD,Walton-Ziegler, Olivia, MS, PA-C