Coloboma of the iris Health Article

Definition

Coloboma of the iris is a congenital (present since birth) defect of the iris of the eye.

Considerations

Coloboma of the iris may appear as a black, round hole located in or next to the colored portion of the eye (iris). It can appear as a black notch of varying depth at the edge of the pupil, giving the pupil an irregular shape. It can also appear as a split in the iris from the pupil to the edge of the iris.

A small coloboma, especially if it is not attached to the pupil, may allow a secondary image to focus on the back of the eye, causing:

• Blurred vision
• Decreased visual acuity
• Ghost image

The defect may extend to the retina, choroid, or optic nerve.

Colobomas are generally diagnosed at, or shortly after birth.

Common Causes

Coloboma can occur due to:

• Eye surgery
• Hereditary conditions
• Trauma to the eye

Most cases of coloboma have no known cause and are not associated with other abnormalities. A small percentage of people with coloboma have other inherited developmental abnormalities.

Call your health care provider if

Contact your health care provider if:

• You notice that your child has what appears to be a hole in the iris or an unusual-shaped pupil.
• Your child's vision becomes blurred or decreased.

Note: It is appropriate to see an ophthalmologist for vision problems. Your primary health care provider may need to help rule out disorders associated with coloboma of the iris.

What to expect at your health care provider's office

The doctor will take a medical history and conduct an examination.

The patient is usually an infant, and the family history will be most important.

The physical examination will include a detailed eye examination, which may involve:

• Dilated exam
• MRI imaging of the brain and nerves connecting the eye to the brain

After seeing your health care provider:

You may want to add a diagnosis related to a coloboma to your personal medical record.