Health Encyclopedia

Coloboma of the iris

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.

Review Date:11/13/2007
Reviewed By:Manju Subramanian, M.D., Assistant Professor in Ophthalmology, Vitreoretinal Disease and Surgery, Boston University Eye Associates, Boston, MA. Review provided by VeriMed Healthcare Network.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.