Glaucoma - What You Need To Know


Glaucoma is an eye disease in which the internal pressure in your eyes increases
enough to damage the nerve fibers in your optic nerve and cause vision loss. The increase in pressure happens when the passages that normally allow fluid in your eyes
to drain become clogged or blocked. The reason that the passages become blocked
is not known.



Progressive side vision loss in untreated glaucoma.

Glaucoma is one of the leading causes of blindness in the U.S. It most often occurs in people over age 40. People with a family history of glaucoma, African Americans, and those who are very nearsighted or diabetic are at a higher risk of developing the disease.

The most common type of glaucoma develops gradually and painlessly, without symptoms. A rarer type occurs rapidly and its symptoms may include blurred vision, loss of side vision, seeing colored rings around lights and pain or redness in the eyes.

Glaucoma cannot be prevented but if diagnosed and treated early, it can be controlled. Vision lost to glaucoma cannot be restored. A comprehensive eye examination should include a test to measure the pressure in your eyes, an examination of the inside of
your eyes, your optic nerves and a visual field test to check for changes in your central and side vision.
 

Examination For Glaucoma - Should Include:
  • History evaluation. The doctor or staff will ask questions about your medical and personal history, as well as your family's medical history.
     
  • Measurement of intraocular pressure (IOP) using an instrument called a tonometer (see photo below).

     
      Some tonometers measures the intraocular pressure
    using a pressure-sensitive tip placed gently against the
    eye (Goldman tonometer). Short-acting anesthetic drops
    are normally used to numb the eye with this instrument.

    Other tonometers measure the intraocular pressure by
    directing a brief puff of air gently onto the eye. "Air puff" tonometers are frequently used as screening instruments
    since no drops are required. In glaucoma patients or
    glaucoma suspects, the Goldman tonometer is normally
    used for added precision.

    "Air-puff" tonometer

    		    


  • Examination of the optic nerve with an ophthalmoscope (see photo below).
     
      ophthalmoscopy - The doctor uses drops to dilate
    (widen) the pupil so he or she look at your optic nerves
    using a special instrument called an ophthalmoscope.
    This allows the doctor to look for damage to your optic
    nerves. Various types of ophthalmoscope may be used. The A binocular ophthalmoscope gives the doctor a 3-D
    view of your eye's interior and provides additional
    diagnostic information.
     
     

    Binocular ophthalmoscope

    		    


  • Examination of the visual fields (see photo below).
     
      A perimeter is used to test your visual field. The
    visual field includes both your central and side vision.
    This test can tell the doctor how much vision has
    been lost, even if you notice no impairment. Changes
    due to glaucoma usually follow a particular diagnostic pattern. Other patterns of visual field loss indicate
    the existence of possible neurological diseases, adding
    significantly to the value of this test.

    Perimeter

    		    

Some of these tests may not be necessary for every patient but some tests may be added or repeated more frequently if glaucoma is suspected or if glaucoma damage increases over time.

Note: Because your eye may be dilated during your exam, you may want to bring sunglasses with you to your appointment. Dilation can make your eyes extra sensitive
to light for a short time after your exam.

Who is at Risk?

 Everyone should be concerned about glaucoma and its effects. It is important for each of us, from infants to senior citizens, to have our eyes checked regularly. Early detection and treatment of glaucoma is the only way to prevent vision impairment and blindness. There are a few conditions related to this disease which tend to put some people at greater risk. This may apply to you if:

  • you are over 45 and have not had your eyes examined regularly
  • someone in your family has a history of glaucoma
  • you have abnormally high intraocular pressure
  • you are of African descent
  • you have diabetes
  • You are highly myopic (nearsighted)
  • you have regular, long-term steroid/cortisone use
  • you have a previous eye injury
     
Sources:
1. American Academy of Ophthalomolgy   Back to Top
2. American Optometric Association    
3. National Eye Institute