Coloboma is a defect of one or both eyes that is present at birth (congenital). With coloboma, a part of the eye is missing a piece of its tissue. It may affect parts of the eye, itself or it may affect the eyelid. Coloboma may be caused by certain genes. In some cases, it may be passed along in families. In many cases, the cause is unknown.
There are several types of coloboma. Each type affects a different part of the eye. Coloboma may occur in one eye or both eyes. In some cases, a child can have a different type in each eye. Some types may cause vision problems. Other types don’t affect vision. Vision problems can range from severe to mild. In some cases, a child may have sensitivity to light.
These are the types of coloboma:
Eyelid coloboma. Part of the upper or lower eyelid is missing. This may look like a notch in the skin. This usually does not affect a child’s vision.
Lens coloboma. Part of the lens is missing. The lens is the part of the eye that focuses light coming into the eye. This may cause some problems with vision.
Optic nerve coloboma. Part of the optic nerve is missing. This is the nerve that connects the eye to the brain. This type of coloboma can cause some loss of vision.
Macular coloboma. The macula doesn’t fully develop. The macula is the center of the retina. This usually causes daylight, fine and color vision problems.
Uveal coloboma. This may be a part missing from the colored part at the front of the eye, called the iris. This type may also affect part of the retina, which is the part of the eye that senses light. This type may not always affect vision or it may cause some vision loss.
An eyelid coloboma can be repaired with surgery. In some cases, an iris coloboma can also be corrected with surgery. Colored contact lenses can cover a coloboma of the iris. No treatment is available to correct other types of coloboma. But those types can be managed. For types of coloboma that cause vision problems, there may be ways to help improve vision. Your child’s doctor or a low-vision specialist may recommend certain tools. These may include low-vision aids. Early intervention for a young child can help prevent learning problems. See “Home care” below for more information.
Follow the healthcare provider’s instructions for ways to help your child’s vision. This may include using:
Glasses with special filters
High-contrast reading materials
Special computer software
If coloboma is only in one eye, the other eye may be treated with an eye patch or glasses to prevent a problem called lazy eye (amblyopia).
Follow up with your child’s primary healthcare provider. He or she may refer your child to a low-vision specialist for further treatment.
Your child will need regular eye exams. These are to check for other problems that can occur in a child with coloboma, such as:
Increased pressure in the eye (glaucoma)
Clouding of the lens (cataract)
Involuntary back-and-forth movement of the eye (nystagmus)
Detaching of the retina from the back of the eye
A child with coloboma may also have other medical problems. These can include heart or kidney defects, or a small eye (microphthalmia). Your child may also have a genetic condition such as CHARGE syndrome, Wolf-Hirschhorn syndrome, or Kabuki syndrome. Talk with your child’s healthcare provider about your child’s risk of these problems.
When to seek medical advice
Call your child's healthcare provider right away if any of these occur: