Coloboma: Causes, Symptoms, and Treatment
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Coloboma?
An ophthalmologist, an eye specialist, is the main doctor for coloboma. Children with coloboma often need specialized care. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is coloboma?
Coloboma is an eye condition that people are born with. It happens when part of the tissue that makes up the eye is missing. It can affect 1 or both eyes. A coloboma can look like a notch or a gap in the iris, the colored part of the eye. It can also affect the retina, the light-sensitive tissue that lines the back of the eye. Coloboma can also affect the eyelids. Coloboma occurs in approximately 1 in 10,000 people.
Symptoms
Some people with coloboma have no symptoms. Others may have problems with their vision, including:
- Vision loss or blindness.
- Low vision, which means vision loss that cannot be completely corrected with glasses or contact lenses.
- Sensitivity to light.
Colobomas that affect the iris generally do not lead to vision loss. An iris coloboma can make the pupil, the round opening at the center of the iris, look more like a keyhole or teardrop. Colobomas that involve the retina result in vision loss in specific parts of the visual field. Large retinal colobomas or those that affect the optic nerve can cause low vision. People with coloboma may also have other eye problems, such as:
- Microphthalmia, which means unusually small eyes.
- Cataract, a cloudy area in the lens of the eye.
- Glaucoma, a group of eye diseases that can cause vision loss or blindness.
- Refractive errors, like nearsightedness or farsightedness.
Causes and who gets it
A baby's eye does not develop normally during pregnancy in a coloboma. Abnormal or changed genes that affect eye development are one cause. Around the second month before birth, a seam called the optic fissure closes to form the structures of the eye. When the optic fissure does not close completely, the result is a coloboma. Coloboma sometimes runs in families. Most often, isolated coloboma is not inherited, and there is only one affected individual in a family. Isolated means the coloboma occurs by itself. Environmental factors, such as drinking alcohol during pregnancy, may also increase a baby's risk. Coloboma often happens together with conditions that affect other parts of the body, like CHARGE syndrome and Wolf-Hirschhorn syndrome.
How doctors diagnose it
Coloboma may be visible when a baby is born. In that case, the doctor may be able to diagnose it by looking at the eyes during an exam. If the coloboma is not visible, the doctor can diagnose it with a comprehensive dilated eye exam. For coloboma of the iris, the provider will do a detailed eye exam that includes looking into the back of the eye while the eye is dilated. An MRI of the brain, eyes, and connecting nerves may be done if other problems are suspected. Because coloboma of the iris is most often diagnosed in infants, knowing the family history is very important.
Treatment
Treatment cannot replace the part of the eye that is missing because of coloboma. But there are treatments that can help people make the most of their vision. These treatments can help:
- Glasses or contacts. People with refractive errors may need them to see more clearly.
- Colored contact lenses can make the pupils look rounder for people with iris colobomas.
- Surgery. People with iris colobomas sometimes get surgery to make their pupils look rounder.
- Low vision aids. If vision loss cannot be corrected with glasses or contacts, special devices can help you see better.
- An eye patch or eye drops. Children who have coloboma in only 1 eye may need them to prevent amblyopia, or lazy eye.
Children and adults may need treatment for other eye conditions related to coloboma, such as cataracts or glaucoma.
When to see a doctor
Contact your child's health care provider if you notice what appears to be a hole in the iris or an unusual-shaped pupil. Also contact the provider if your child's vision becomes blurred or decreased. Your child may also need to see an eye specialist, called an ophthalmologist. If your child has coloboma, talk to the doctors about the best plan for their care. Call 911 or go to the emergency room if you have a sudden change in vision.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Contact your child's health care provider if you notice what appears to be a hole in the iris or an unusual-shaped pupil. Your child may also need to see an eye specialist, called an ophthalmologist.
Common questions
Can treatment replace the missing part of the eye in coloboma?
No, treatment cannot replace the part of the eye that is missing because of coloboma. But there are treatments that can help people make the most of their vision.
Does coloboma always affect vision?
No, some people with coloboma have no symptoms. Colobomas that affect the iris generally do not lead to vision loss. Colobomas that involve the retina result in vision loss in specific parts of the visual field.
Is coloboma inherited?
Sometimes. Coloboma sometimes runs in families. Most often, isolated coloboma is not inherited, and there is only one affected individual in a family. Isolated means the coloboma occurs by itself.
Sources
- National Eye Institute - Coloboma
- MedlinePlus Genetics - Coloboma
- MedlinePlus - Coloboma of the iris
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
