Was this helpful?

What is glaucoma?

Glaucoma is the name for a number of conditions that damage the optic nerve, usually as a result of increased pressure within the eye that results when the naturally occurring fluid (aqueous humor) in the eye does not drain properly out of the eye. Slow drainage may occur with normal eye anatomy (open-angle glaucoma) or with structural problems in the drainage mechanism (angle-closure glaucoma). The optic nerve damage of glaucoma usually affects your peripheral vision first, leading to tunnel vision, and moves progressively to involve your central vision.

The most common type of glaucoma is called open-angle, or chronic, glaucoma and is caused by a gradual buildup of pressure in the eye over time. A less common form of open-angle glaucoma, called normal-tension glaucoma, shows optic nerve damage even though the eye pressure is normal. Another type of glaucoma is angle-closure, or acute, glaucoma, in which the drainage mechanism becomes blocked and causes an abrupt increase in eye pressure. Glaucoma can also be present at birth (congenital glaucoma) or may occur as a result of medications, medical conditions, or surgery (secondary glaucoma).

Although glaucoma can affect anyone, it is generally found in people over the age of 60 years. In addition, African Americans are about five times more susceptible to developing glaucoma than other patient populations and may develop it at an earlier age. Finally, those with a family history of glaucoma are more likely to develop glaucoma themselves (Source: NEI).

In most cases, glaucoma progresses silently, without any symptoms, until visual damage has already occurred. Thus, it is essential to get regular eye examinations, especially if you are African American or have a family history of glaucoma. Timely treatment can usually stop the progression of glaucoma. Left untreated, glaucoma can cause permanent vision alterations or blindness.

Although glaucoma is not life threatening, it can have serious visual complications. In most cases, visual loss occurs slowly over time. However, angle-closure, or acute, glaucoma can come on suddenly and cause permanent eye damage or vision loss if not immediately treated. Seek immediate medical care (call 911) for serious symptoms, including eye pain, blurred vision, headache, halos seen around lights, loss of vision, or nausea with vomiting.

What are the symptoms of glaucoma?

Symptoms of glaucoma vary depending on the specific type of glaucoma that you have. You should seek prompt medical attention as soon as you notice any symptoms of glaucoma. It is also important to get regular eye examinations, since open-angle glaucoma usually does not have symptoms until damage has already occurred.

Common symptoms of open-angle glaucoma

Open-angle glaucoma exhibits no symptoms until you have already lost some vision. Loss of vision typically starts at the sides of your visual field, leading to tunnel vision, and progresses toward the center of your vision.

Common symptoms of angle-closure or acute glaucoma

Angle-closure glaucoma typically exhibits a sudden onset of symptoms. At times any of these symptoms can be severe:

  • Abdominal pain (stimulation of the vagus nerve)
  • Eye pain
  • Halos seen around lights
  • Headache accompanied by eye symptoms
  • Loss of vision or changes in vision
  • Nausea with or without vomiting
  • Red, sore eyes (bloodshot eyes)

Common symptoms of congenital glaucoma

Congenital glaucoma is present at birth, although symptoms are not generally recognized until several months of age. These symptoms include:

  • Haze in the normally clear cornea (front of the eye)
  • Increased sensitivity to light
  • Red, sore eyes (bloodshot eyes)
  • Swelling of one or both eyes

Common symptoms of secondary glaucoma

The symptoms of secondary glaucoma can be the same as either open-angle or angle-closure glaucoma, depending on the specific cause. Secondary glaucoma can result from certain medications, medical procedures, or other medical conditions.

Symptoms that might indicate a serious condition

Acute angle-closure glaucoma is a serious condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these serious symptoms including:

  • Blurred vision
  • Eye pain
  • Halos seen around lights
  • Headache
  • Loss of vision or changes in vision
  • Nausea with or without vomiting

What causes glaucoma?

Glaucoma is typically caused by a buildup of pressure within the eye. This increase in pressure is generally due to an excess of naturally occurring fluid (aqueous humor) in the eye when the drainage mechanism cannot keep up with the rate of fluid production. However, the optic nerve damage typical of glaucoma can also occur without an increase in pressure within the eye. You can also have increased eye pressure, known as ocular hypertension, without any damage to your optic nerve or vision.

In open-angle glaucoma, the eye’s anatomy looks normal, and the cause of the increased pressure is usually not known. Angle-closure glaucoma occurs as a result of an anatomic abnormality or obstruction involving the anterior chamber angle, which is an important part of the eye’s drainage pathway. Congenital glaucoma is usually the result of delayed or abnormal anatomic development of the eye’s drainage mechanism.

Secondary glaucoma has many possible causes, including certain medications, especially corticosteroids; eye surgery, such as corneal transplants or cataract surgery; and eye trauma.

What are the risk factors for glaucoma?

A number of factors increase the risk of developing glaucoma. Not all people with risk factors will get glaucoma. Risk factors for glaucoma include:

  • African American race, especially over the age of 40 years

  • Age (over 60 years in Caucasians; over 40 years in African Americans)

  • Diabetes

  • Family history of glaucoma

  • History of ocular trauma

  • Hyperopia (farsightedness)

  • Mexican American ethnicity, especially over the age of 60 years

  • Smaller than normal eye size

Reducing your risk of glaucoma

The risk of developing glaucoma cannot be reduced. However, you may be able to reduce your risk of complications of glaucoma, including vision impairment or loss, by having regular eye examinations (frequency depends on your age and other risk factors).

How is glaucoma treated?

The best way to treat glaucoma is to make sure it is diagnosed early. The most common type of glaucoma has no symptoms until visual damage has already occurred. Treatment of glaucoma begins with getting regular eye examinations from a health care professional. Although glaucoma usually cannot be cured, all types of glaucoma can be treated. The goal of treatment is to prevent further damage from occurring; it cannot reverse damage that is already present.

Treatment typically involves the application of eye drops or oral administration of medications to decrease the pressure in the eye. For patients with acute glaucoma, emergency medications may be given through a vein (intravenously).

Additional treatment methods include laser or traditional surgery to make the fluids drain more easily through existing drainage channels or to create new channels.

What are the potential complications of glaucoma?

Potential complications of glaucoma are not life threatening. However, left untreated, glaucoma can lead to serious visual complications, even blindness. You can help minimize your risk of serious complications by getting prompt medical care and following the treatment plan you and your health care professional design specifically for you. Complications of glaucoma include:

  • Chronic corneal edema (loss of transparency)
  • Loss of central or side (peripheral) vision
  • Loss of vision or changes in vision
Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Nov 27
View All Eye Health Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Glaucoma. PubMed Health, a service of the NLM from the NIH.
  2. Facts about glaucoma. National Eye Institute.
  3. Tierney LM Jr., Saint S, Whooley MA (Eds.) Current Essentials of Medicine (4th ed.). New York: McGraw-Hill, 2011.