Glaucoma is a group of diseases that can damage the eye’s optic nerve and may result in vision loss and blindness. Multiple factors are often important in causing glaucoma, but it is most commonly related to an increase in pressure in the eye. Symptoms are generally absent until the condition has progressed to an advanced stage.  Very occasionally, a rarer form of glaucoma can develop suddenly and symptoms may then include: headaches and aches around the affected eye, seeing halos around lights, sensitivity to light, blurred vision, nausea and vomiting.
You may be more likely to develop glaucoma if you:
  • have someone else in your family with glaucoma
  • already have high pressure in your eye
  • have experienced injury to your eye
  • have or have had certain other eye problems
  • have migraine or circulation problems.
Glaucoma is more common in people over 50 years of age and more common in women than men. Actual diagnosis of glaucoma can be difficult and may take months or even years, with repeat testing to determine its presence or absence. Diagnosis is usually confirmed by an eye doctor but signs of glaucoma may also be picked up at an optometrist’s eye examination.
The following tests are used to diagnose and monitor glaucoma:
  • Tonometry – measures eye pressure.  It is often the first screening test for glaucoma. The eyes are numbed with eye drops and then examined. 
  • Dilated eye exam - this is done with an ophthalmoscope (which is a medical instrument that allows the doctor to look through the pupil to the back of the eye).The retina and optic nerve are then examined for any sign of damage. 
  • Visual acuity test – test to check distance vision using an eye chart.
  • Visual field test – test to measure side (peripheral) vision. 
  • Pachymetry – test to measure the thickness of the cornea.
  • OCT - Nerve fibre layer measurement can aid in diagnosing and monitoring glaucoma.
  • Digital photo's - used to obtain a baseline reading of the optic nerve and monitor any possible glaucoma changes over time.
Many other new techniques are emerging to help identify the likelihood of glaucoma and help determine its rate of worsening. Although glaucoma cannot be cured, early treatment can prevent further worsening of the condition and vision loss. Regular eye examinations will need to be continued life-long. 
When you attend for your initial assessment please bring your glasses with you and any medication you take on a regular basis. It is advisable to bring a driver to your appointment as you may have dilating drops put in your eyes and this can make driving home difficult. You will have some of the tests listed above at your initial appointment and may then require repeat testing on a regular basis if glaucoma is suspected.
Eye drops to decrease eye pressure are the most common early treatment.  Surgery may be required, especially if medications are not taking adequate effect. 
Laser trabeculoplasty, in which a surgeon uses a laser to help the fluid drain from the eye, may be considered in some cases, but has limited effectiveness.
More commonly, a trabeculectomy may be performed when other methods have failed to adequately control pressure. This is a medium length operation that makes a new opening for fluid to drain from the eye.

This page was last updated at 10:22AM on November 17, 2021.