Home > Medical Reference > Encyclopedia (English)

Toggle: English / Spanish

Coloboma of the iris - All Information

Definition of Coloboma of the iris:

Coloboma of the iris is a hole or defect of the iris of the eye. Most colobomas are present since birth (congenital).

Considerations:

Coloboma of the iris may look like a black, round hole located in or next to the colored part of the eye (iris). It can look like a black notch of different depths at the edge of the pupil. This gives 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 second image to focus on the back of the eye, causing:

Blurred vision
Decreased visual acuity
Ghost image

The defect may include the retina, choroid, or optic nerve.

Colobomas are generally diagnosed at, or shortly after, birth.

Common Causes:

Coloboma can occur due to:

Eye surgery
Inherited conditions
Trauma to the eye

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

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:

Your health care provider will take a medical history and do 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.

Eye

Cat eye

Coloboma of the iris

Reviewed last on: 10/31/2009
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

References

Olitsky SE, Hug D, Smith LP. Abnormalities of pupil and iris. In: Kliegman RM, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 621.

Guercio JR, Martyn LJ. Congenital malformations of the eye and orbit. Otolaryngol Clin N Am. 2007;40:113-140.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

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 an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. 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 policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

Connect with UMMC

© 2011 University of Maryland Medical Center (UMMC). All rights reserved.
UMMC is a member of the University of Maryland Medical System,
22 S. Greene Street, Baltimore, MD 21201. TDD: 1-800-735-2258 or 1.866.408.6885