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.
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.
When to Contact a Medical Professional
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.
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.
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.
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