Buphthalmos is a general term for an enlarged eye. It’s often used describe unusually large eyes in children under the age of 3, and it can affect one or both eyes. Buphthalmos is usually a symptom childhood glaucoma, which tends to develop within the first year after birth.

The main symptom of buphthalmos is an enlarged eye. However, if it’s caused by childhood glaucoma, you might also notice:

Childhood glaucoma is the most common cause of buphthalmos. Glaucoma is an eye disease in which pressure in the eye, called intraocular pressure, builds up and damages the optic nerve. The increase in pressure is usually caused by a problem with the eye’s drainage system, which causes a buildup of fluid.

Childhood glaucoma can also be caused by other conditions, such as:

  • aniridia, which refers to not having an iris — the colored part of the eye
  • neurofibromatosis type 1 (aka, von Recklinghausen disease), a central nervous system disorder
  • sclerocornea, a condition that involves the white coating of the eye, called the sclera, blending with the clear front part of the eye, called the cornea
  • Sturge-Weber syndrome, a neurological disorder that causes red birthmarks on the forehead and eyelid

Your child’s pediatrician will likely diagnose buphthalmos during an eye exam. They may refer you to a pediatric ophthalmologist for further testing. Tests may include:

Depending on how your child responds to these exams, their pediatrician may recommend anesthesia during testing.

Children over 3 rarely develop a new case of buphthalmos. If your child is over the age of 3 and has an enlarged eye, it may be related to a different cause, such as hyperthyroidism.

Treating buphthalmos usually involves reducing pressure in the eye. This is sometimes done with medicated eye drops including beta blockers, which are medications commonly used to lower blood pressure. If your child has glaucoma, their pediatrician may also recommend:

  • implants to help with drainage
  • goniotomy, which involves creating openings for drainage
  • cyclodestructive surgery, which removes the part of the eye creating the extra fluid
  • partial sclera removal to improve drainage

In addition to medication and surgery, your child may also need to wear glasses.

Buphthalmos tends to get worse over time. Left untreated, the enlarged eye can stretch the surrounding tissue and cause permanent damage.

Buphthalmos may not be preventable, but regular pediatric eye exams can help you catch it early. If it’s related to a degenerative eye condition, such as glaucoma, early treatment can greatly reduce your child’s risk of having permanent eye damage.

Buphthalmos is relatively rare. According to the American Academy of Optometry, this condition affects about 1 in every 30,000 infants. Make sure your child has regular eye exams to check for any problems, including buphthalmos.