What is aniridia?
Aniridia is a serious and rare eye disorder that affects the colored part of the eye (iris). Aniridia means lack of an iris. With this condition, the iris is partly or fully gone. The pupil is abnormally large and may be oddly shaped. This condition often happens in both eyes. It can also affect the cornea, anterior chamber, lens, retina, and optic nerve. Some of these problems are present from birth (congenital). Others may happen later in life.
The iris 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.
Often aniridia happens on its own. In some cases, it is one of several syndromes that are linked to other symptoms. It affects males and females about equally. It may be more common in certain parts of the world.
What causes aniridia?
Experts think many cases happen because of a change (mutation) in the gene called PAX6. PAX6 is part of the genetic information you pass to your children. This gene is key for eye health and development. If PAX6 doesn’t work right, your eyes may not develop correctly. 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 it are autosomal dominant. That means that a child of a parent with aniridia has a 50 out of 100 chance of having it. But some people who have aniridia don’t have any family members with the condition.
What are the symptoms of aniridia?
Aniridia can cause many symptoms, such as:
- Poor vision (not always present)
- More sensitivity to light
- Eye movements that can't be controlled (nystagmus)
- Eyes don't line up (strabismus)
Often this condition affects only your eyes. But some people have aniridia along with other symptoms. The most common are Wilms tumor (a kidney tumor), genitourinary problems, and intellectual disabilities. Together with aniridia these are known as WAGR (Wilms tumor-aniridia-genital anomalies-range of developmental delays). 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 often happens at a young age. A healthcare provider will ask about your child’s health history and do 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, other tests may be needed. These can help get information about the genes involved.
How is aniridia treated?
Children with this condition 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 how the eyes look.
An eye care provider may also treat aniridia by replacing the iris with an artificial iris. This is done with surgery.
What are possible complications of aniridia?
Aniridia can cause severe problems. Many of these 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 adults who don’t have aniridia. But with aniridia, they happen at an earlier age. Complications can include:
- Aniridia-related keratopathy. The cornea becomes less clear. It makes vision worse.
- Glaucoma. This is too much fluid buildup in the eye. It happens most often in teens with aniridia.
- Cataract. This is clouding of the lenses of the eyes. This can make it harder to see.
- Problems with the optic nerve. This nerve sends visual information to the brain.
- Retinal tearing or detachment. The retina is the light-sensitive part on the back of the eye. Retinal detachment can cause severe vision loss without surgery to fix it.
These problems can cause many symptoms, including:
- Blurred vision
- Blindness in part of the field of vision
- Flashes of light in the eye
- Eye pain
Your child might need medicated eye drops or surgery to treat these problems.
How to manage aniridia
Most children with this condition will be able to go to a normal school. But your child may need extra support in the classroom to cope with visual issues.
You may find a support group helpful. Aniridia Foundation International is a support group for people with aniridia and their families.
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. The iris is partly or fully gone, often in both eyes. It can also affect other parts of the eye.
- Your child may have certain problems from birth, such as increased light sensitivity.
- Other eye problems may develop later, such as cataracts or glaucoma.
- Your child may need to wear special contact lenses or glasses to protect his or her eyes.
- Regular eye checkups are needed. Your child's eye care provider will check visual sharpness and watch for problems.
- Surgery may be needed.
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