What Is Buphthalmos?

Medically Reviewed by Dan Brennan, MD on May 18, 2021

Buphthalmos means that one or both eyeballs are larger than normal. Your child’s doctor would typically notice the enlargement when your child was born or shortly after. Most of the time, buphthalmos is a symptom of fluid building up in the eye.

What Causes Buphthalmos?

The eye of a baby or young child is extremely soft and easily changeable. This must be the case, because a healthy child’s eye grows a great deal while they are in the womb and during the first few years of life. If there is a build-up of fluid in the eyeball, the pressure from the fluid can make the eye grow too large.

The high pressure can also damage the optic nerve that carries signals from the eye to the brain. This is called glaucoma. In most cases of glaucoma, there is a problem with the drainage system of the eye. Your eye is supposed to continually make fluid and then drain it away. If the fluid can’t drain, pressure builds.

Other Signs of Glaucoma

Glaucoma is rare in children, and some of the symptoms may be hard to spot. Along with buphthalmos, babies and toddlers with glaucoma may:

  • be unable to see well
  • be overly sensitive to light
  • close one or both eyes when in bright light
  • have eyes that look cloudy
  • have one eye that is bigger than the other
  • have excess tearing (watery eyes) without discharge such as mucus or pus
  • be fussy and uncomfortable
  • have a poor appetite

How Is Glaucoma Diagnosed in a Young Child?

‌Children with buphthalmos are usually too young to cooperate with an eye exam. The doctor will probably give your child anesthesia (medicine to put them to sleep so they can’t feel the exam).

Within the first few minutes they are asleep, the doctor tests the pressure level in each eye. They will look carefully at each part of the eye, taking measurements and looking for signs of glaucoma such as cloudiness or breaks in the cornea (the clear cover on the front of the eye).

The doctor will check the drainage system of the eyes to find out if there’s a blockage or problem with the way the drainage canals developed. They will test to see if there has been any damage to the optic nerve yet. They can also check for vision problems that can be helped with glasses.

Treatment Options

‌The goal of glaucoma treatment is to lower the pressure to keep it from causing any more damage to the optic nerve. In babies and toddlers with glaucoma, this usually means surgery. It is important to treat glaucoma quickly to preserve as much vision as possible.

If surgery cannot be done right away, there are medicines that can help clear the eye and lessen the pressure before the surgery.  These are almost always in the form of eyedrops. Sometimes children with glaucoma have to keep using prescription eyedrops, even after surgery.

The three types of eyedrops that may be prescribed for your child are beta-blockers, carbonic anhydrase inhibitors, and prostaglandin analogs.

Beta-blockers. These eyedrops reduce the amount of fluid the eye makes. The less fluid, the lower the pressure in the eye.

Carbonic anhydrase inhibitors. These medications also help decrease the amount of fluid made in the eye. They come in eyedrops or can be taken by mouth.

Prostaglandin analogs. These eyedrops increase the amount of fluid that drains out of your child’s eye. This is another way to lower the pressure in the eye.

There are several surgeries that can help fluid drain from the eye. These include:

Goniotomy. The surgeon makes openings in the tiny canals that drain the eye. This clears a path for the fluid to drain like it’s supposed to.

Drainage shunts. The surgeon places tiny tubes in the eye or eyes to drain away extra fluid.

Trabeculectomy. This is sometimes known as filtering surgery or micro surgery. The doctor uses surgical tools to make an opening in the white of the eye. They remove a small amount of tissue to create a path for fluid to drain from the eye to a place where the body can absorb it.

Laser surgery. The doctor uses a powerful beam of light to clear any clogs in the canals that drain the eye.

Impact of Buphthalmos on Your Health

Even with surgery and medicine, your child may eventually need glasses for myopia (nearsightedness). Some children with glaucoma also develop amblyopia (a lazy eye) or strabismus (crossed eyes). They may later need treatments like vision therapy, surgery, or patching (covering or putting eyedrops in the stronger eye to strengthen the weaker eye).

Show Sources


‌American Association for Pediatric Ophthalmology and Strabismus: “Glaucoma for Children.”

‌Aslam, S. and Gupta, V. Carbonic Anhydrase Inhibitors, StatPearls, 2021.

Feroze, K. and Bhupendra C. Buphthalmos, StatPearls, 2021.

Boston Children’s Hospital: “Glaucoma in Children.”

Glaucoma Research Foundation: “Childhood Glaucoma.”

‌Mayo Clinic: “Glaucoma.”

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