What is glaucoma?

Glaucoma refers to a group of conditions that cause damage to the optic nerve and reduce a person's ability to see. Glaucoma is a very common condition and has become the second-leading cause of blindness worldwide.1

In glaucoma, the optic nerve damage (and resulting vision loss) is usually due to abnormally high pressure within the eye. The pressure is caused by excess amounts of a fluid called aqueous humor. In a healthy eye, aqueous humor is produced and then drained in the front part of the eye. When the drainage system becomes blocked, aqueous humor builds up inside the eye and increases pressure.

  • Primary angle closure glaucoma occurs when the tiny fluid drainage channels become blocked. This type of glaucoma is painless, and its only symptom is gradual vision loss. Glaucoma treatments can halt the vision loss, but they cannot restore lost vision. For this reason, it is highly important to undergo regular eye exams to detect the presence of glaucoma or another sight-robbing condition.
  • Angle closure glaucoma occurs when the iris bulges forward, completely or partially blocking the drainage channels. Angle close glaucoma is a painful medical emergency that requires immediate treatment.
  • In pigmentary glaucoma, which can develop in younger patients, pigment granules (the source of eye color) rise from within the iris and block the fluid drainage channels. Like primary angle closure glaucoma, pigmentary glaucoma is painless and must be treated early to prevent further vision loss.
  • In low tension glaucoma, the optic nerve sustains damage despite normal levels of eye pressure. While the exact cause is not understood, physicians theorize it may be due to abnormally sensitive optic nerves or reduced blood flow to the eye. Like primary angle closure glaucoma, low-tension glaucoma is painless and must be treated early to prevent further vision loss.

What are the symptoms of glaucoma?

Primary angle closure glaucoma, pigmentary glaucoma and low-tension glaucoma generally do not produce any early symptoms. As the conditions develop, symptoms include:

  • Gradual loss of peripheral (non-central) vision
  • Tunnel vision, as the condition advances

Angle closure glaucoma is a medical emergency with symptoms including:

  • Eye pain, often severe, with or without nausea and vomiting
  • Sudden disturbance of vision
  • Blurry vision
  • Eye redness
  • Light halos

What are the risk factors for glaucoma?

Vision loss due to glaucoma is permanent, regardless of the type of glaucoma present. It is extremely important to undergo regular visual exams, especially if you have one or more risk factors.

The risk factors for glaucoma include:

  • Older age
  • Ethnicity - African-Americans are five times more likely to develop glaucoma than Caucasians, and are also more likely to develop blindness from glaucoma.
  • Family history of glaucoma
  • Elevated eye pressure
  • Diabetes
  • Hypothyroidism
  • Nearsightedness
  • Using corticosteroids for long periods
  • Severe eye injuries
  • Eye tumors
  • Eye inflammation
  • Retinal detachment

How is glaucoma diagnosed?

To diagnose glaucoma, a Temple ophthalmologist may:

  • Measure eye pressure
  • Test for damage to the optic nerve
  • Test for vision loss
  • Measure corneal thickness - thick corneas can raise eye pressure without the presence of glaucoma
  • Perform gonioscopy - the use of a special lens to inspect the drainage angle and determine the type of glaucoma present

How is glaucoma treated?

Depending on the type and severity of glaucoma, Temple's treatment options include:

  • Medicated eye drops
  • Oral medications
  • Laser surgery
  • Filtering surgery
  • Drainage implants

Learn more about glaucoma treatment at Temple.

To schedule an appointment with a Temple ophthalmologist, click here or call 1-800-TEMPLE-MED (1-800-836-7536).

1World Health Organization