What Is Buphthalmos?

Buphthalmos is an enlargement of the eye due to raised eye pressure that is present at birth or soon after. This is a rare condition that is present in about 1 in 30,000 births. It requires prompt treatment to preserve sight.

The term buphthalmos comes from Greek roots and means "ox-eyed." The ancient physician Hippocrates described it in 400 BC.

This article will take a closer look at buphthalmos, what the symptoms are, what causes this to occur, how to detect the condition, the diagnostic factors, and what treatments to consider.

Symptoms

The most common sign that someone has buphthalmos is an eye that is too large. By age 1, the eye typically has a diameter of between 10 and 11.5 millimeters (mm). A baby with an eye of 12 millimeters before age 1 indicates that there's likely an issue. This is especially suspicious if the other eye is in the normal range, although both eyes can be affected.

Other symptoms that someone with buphthalmos may have can include:

• Asymmetric size of eyes (different sizes for each eye)
• Tearing with no sign of infection
• Sensitivity to light
• Poor vision
• Corneal haze (the cornea is the clear dome of tissue at the front of the eye)
• Blinking or eyelid twitching

Causes

Buphthalmos is often linked to congenital glaucoma cases in which the eye's drainage system does not develop correctly in the first months of life. As the fluid builds up in the eye, the pressure rises. In glaucoma, increased eye pressure damages the optic nerve.

The increased pressure stretches the pliable tissues in the child's eye, including the white scleral layer and cornea, which can result in buphthalmos. While by age 3, the clear cornea stops expanding, up until age 10, the white sclera may continue to stretch.

Some conditions besides glaucoma that have been linked to buphthalmos include:

• Aniridia is a condition in which the iris (the colored portion of the eye) is completely or partially missing. With this condition, the drainage angle to the eye may often be blocked, causing a buildup of pressure in the eye.
• Neurofibromatosis type 1 is a genetic disorder that causes noncancerous tumors. Glaucoma in this condition is potentially linked to issues with the anterior drainage angles.
• Sturge-Weber syndrome is a vascular disorder in which abnormal blood vessels are associated with causing glaucoma.
  

Diagnosis

Determining if someone has buphthalmos requires an eye examination. For young children, this may be done under anesthesia. The examination will likely include the following:

• Intraocular pressure (IOP) measurement
• Corneal diameter measurement with calipers
• Examination of the eye's drainage system (the trabecular meshwork) using gonioscopy (a special mirrored lens to view the front of the eye)
• Examination of the optic nerve with an ophthalmoscope (an instrument that can view the back of the eye)

Treatment

Treatment for buphthalmos revolves around identifying the condition as early as possible to help preserve sight since this can affect the optic nerve. This may involve the use of pressure-lowering medication or performing glaucoma surgery. In some cases, these may be used in combination.

Medications used here may include:

• Beta blocker eye drops are used to reduce the amount of fluid in the eye. These may reduce pressure by up to 30%.
• Carbonic anhydrase inhibitors (taken orally) also lower the amount of fluid in the eye. For children, tablets may be crushed in food. These can lower pressure by up to 35%.
• Prostaglandin analogues can reduce eye pressure up to 20%. This medication reduces pressure by increasing fluid outflow. However, these have not been approved by the Food and Drug Administration (FDA) for children.

Surgery is another option for lowering pressure. There are four major approaches that are taken here. Possible procedures here include the following:

• Goniotomy treatment is a procedure where a small opening is made in the drainage system to help fluid flow out of the eye better.
• Tube shunt treatment uses a flexible tube to help fluid drain out of the eye.
• Selective laser trabeculoplasty is when a laser treats the eye's drainage angle to enable fluid to flow more freely through it.
• Trabeculectomy involves surgically creating a new drainage pathway that allows fluid to more efficiently leave the eye, enabling eye pressure to drop.

Summary

Buphopthalmus is a rare condition present at birth. An increase in eye pressure, usually in a child's pliable eye, causes the globe to grow larger in one or both eyes. It's important to detect it as early as possible in order to preserve sight. Treatment can include medication, surgery, or some combination of these.

A Word From Verywell

While noticing that something is amiss with one or both of your child's eyes can be alarming, these days, healthcare providers understand how to best treat this troubling eye condition. There is, fortunately, no shortage of approaches for managing the increased eye pressure associated with buphthalmos and helping to preserve your child's vision.