MedlinePlus Medical Encyclopedia: Coloboma of the iris

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Coloboma of the iris

Contents of this page:
Illustrations Definition Considerations Common Causes	Home Care Call your health care provider if What to expect at your health care provider's office

Illustrations

Eye

Cat eye

Coloboma of the iris

Definition Return to top

Coloboma of the iris is a congenital (present since birth) defect of the iris of the eye. It is visible as a hole, split, or cleft in the iris.

Considerations Return to top

Coloboma of the iris may appear as a black, round hole located in or adjacent to the iris (colored portion of the eye). 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 a ghost image, blurred vision, or decreased visual acuity.

Coloboma may be associated with hereditary conditions, trauma to the eye, or eye surgery. The defect may extend to the retina, choroid, or optic nerve.

Common Causes Return to top

Cat-eye syndrome
Trisomy 13
Trisomy 18
Marfan's syndrome
Rubinstein-Taybi syndrome
Sturge-Weber disease
Basal cell nevus syndrome
Variation of normal (some colobomas can be inherited as an autosomal dominant trait)

Home Care Return to top

Colobomas are generally diagnosed at, or shortly after birth. There is no home care.

Call your health care provider if Return to top

You notice that your child has what appears to be a hole in the iris or an unusual-shaped pupil.
Vision becomes blurred, or decreased vision is noted.

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 Return to top

The medical history will be obtained and a physical examination performed.

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

The physical examination will include a detailed eye examination. A dilated exam of the inside of the eye should be done. Other tests may include 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.

Update Date: 1/19/2004

Updated by: Raymond S. Douglas, M.D., Ph.D., Department of Ophthalmology, UCLA Medical Center, Los Angeles, CA. Review provided by VeriMed Healthcare Network.

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