Facts on Glaucoma

• Glaucoma is a group of eye diseases that damage the optic nerve (the bundle of nerve fibers that carries information from the eye to the brain), leading to vision loss and possibly blindness.
  
  
• Optic nerve damage usually occurs in the presence of high eye (intraocular) pressure. However, glaucoma can be diagnosed with normal or even lower than normal eye pressure.
  
  
• Worldwide, an estimated 66.8 million people are visually impaired due to glaucoma, and an estimated 6.7 million are blind.
  
  
• In the U.S., approximately 2.2 million people age 40 and older have glaucoma, and of these, as many as 120,000 are blind.
  
  
• An estimated 3.3 million of Americans could have glaucoma by the year 2020. Vision experts believe that half of those affected by glaucoma may not know it, since there are usually no symptoms in its early stages.
  
  
• Glaucoma is a leading cause of blindness among African Americans and Hispanics in the U.S. Three times as many African Americans have glaucoma than Caucasians, and four times as many are blind. Between the ages of 45 and 64, glaucoma is fifteen times more likely to cause blindness in African Americans than in Caucasians.
  
  Strong risk factors for open-angle glaucoma include:
  
  
  • High eye pressure
  • Family history of glaucoma
  • Age 40 and older for African Americans
  • Age 60 and older for the general population, especially Mexican Americans
  • Thin cornea
  • Suspicious optic nerve appearance with increased cupping (size of cup, the space at the center of optic nerve, is larger than normal)
    
    
  Potential risk factors for open-angle glaucoma include:
  
  
  • High myopia (very severe nearsightedness)
  • Diabetes
  • Eye surgery or injury
  • High blood pressure
  • Use of corticosteroids (for example, eye drops, pills, inhalers and creams)
    
    
• There are two main forms of glaucoma: open-angle (the most common form that affects approximately 95% of individuals) and closed-angle.
  
  
• Open-angle glaucoma, by far the most common form, initially has no symptoms. At some point, side (peripheral) vision is lost and without treatment, an individual can become totally blind.
  
  
• Closed-angle glaucoma comes in two forms: acute or chronic.
  
  
• Acute closed-angle glaucoma occurs when the normal flow of aqueous humor between the iris and the lens is suddenly blocked. Symptoms may include severe pain, nausea, vomiting, blurred vision and a rainbow halo appearing around lights. Acute closed-angle glaucoma is a medical emergency that must be treated immediately or blindness can result in one or two days.
  
  
• Chronic closed-angle glaucoma progresses slowly and can produce damage without symptoms, similar to open-angle glaucoma.
  
  
• There are also several other forms of glaucoma, including normal-tension, congenital, juvenile and secondary. Secondary glaucoma can be open-angle or closed-angle and results from another medical condition in the eye or body. Examples of secondary glaucoma include pseudoexfoliation syndrome, neovascular, pigmentary, and iridocorneal endothelial syndrome (ICE syndrome).
  
  
• Eye doctors use several tests to detect glaucoma including: visual acuity test, visual field test, dilated eye exam, tonometry, pachymetry, ophthalmoscopy, gonioscopy and optic nerve imaging.
  
  
• Individuals at high risk for glaucoma should have a dilated pupil eye examination, including a visual field test, every 1-2 years or as directed by a doctor.
  
  
• Currently, there is no cure for glaucoma; however, through early diagnosis and treatment, the disease can be controlled before vision loss or blindness occurs. Treatments for open-angle glaucoma include: medications, usually eye drops, to help eye fluid drain more effectively or lessen fluid production; laser surgery; and conventional surgery.
  
  
• New treatment research is focused on lowering pressure inside the eye, finding medications to protect and preserve the optic nerve from the damage that causes vision loss, and the role of genetic factors.

Source: Some of the information in this fact sheet was obtained from the National Eye Institute. The American Health Assistance Foundation is grateful to Carla J. Siegfried, M.D. at Washington University in St. Louis, Missouri for reviewing aspects of the above content.

Last Reviewed On: 11/07/08