Glaucoma

Glaucoma is an eye disease in which progressive damage to the optic nerve results in permanent vision loss.

Damage can occur for many years without any symptoms. Therefore, regular eye checks from the age of 45 years are recommended. These checks help identify glaucoma at an early stage before extensive vision loss has occurred. Treatments are available to help prevent further damage. If glaucoma is not treated and the optic nerve dies completely, blindness can occur. 

Key points

  1. Glaucoma is the main preventable cause of blindness in New Zealand.
  2. More than 1 in 10 people over 80 years of age have glaucoma.
  3. If you are over 45 yrs of age, you should have your eyes checked every 5 years by an optometrist, or every year if you are over 60 yrs. 
  4. Seek urgent medical advice if you experience sudden changes in your vision or pain in your eye.
  5. With proper care, less than 2% of patients with glaucoma will go blind. 
 

(What is glaucoma? EyeSmart — American Academy of Ophthalmology)

Causes

At the front of the eye, there is a small space for a clear fluid to flow in and out to wash the eye and feed nearby tissues. In glaucoma, the fluid drains too slowly out of the eye (we don’t know why). As the fluid builds up, the pressure inside the eye increases. Unless this pressure is controlled, it may cause damage to the optic nerve and other parts of the eye, leading to loss of vision.

How is vision lost?

The optic nerve carries information about an image from the eye to the brain. When the optic nerve is damaged and starts to die, it can no longer carry all the information about an image from the eye to the brain. If the brain does not get all the information, we are unable to see all the image. If the optic nerve dies completely, blindness occurs. 

Who is most at risk?

You are at an increased risk of glaucoma if you:

  • Are older than 40 years.
  • Have a family history of glaucoma.
  • Have near-sightedness (myopia).
  • Have diabetes.
  • Have high blood pressure.
  • Have a history of migraine.
  • Use cortisone or steroids.
  • Have a previous eye injury.

If you fit into one of these risk groups, go to an eye care professional (known as an optometrist) at least every one to two years for an eye check.

Symptoms

In most cases of glaucoma, there are no symptoms. As many as half of all people with glaucoma may be unaware they have the disease.

  • Vision loss usually starts at the outside edge of the eye.  At this stage, vision may seem a bit fuzzy around the edges.
  • Most people don’t notice this fuzziness until a lot of nerve damage has occurred.
  • Eventually, this fuzziness increases until blindness occurs.



Photograph showing typical glaucoma. 

When to seek urgent medical help

In a few cases, glaucoma will develop rapidly with:

  • blurred vision
  • loss of side visions
  • seeing coloured halos around lights
  • redness of the eye
  • nausea or vomiting
  • pain in the eye.

These are all serious symptoms and you should see a doctor immediately. 

Prevention

What can I do to protect my vision? Glaucoma is easy to treat when found early.

  • If you are over 60 yrs of age, you should have your eyes checked every year.
  • If you are in any of the higher risk groups above, have an eye check at least every one to two years.

The 45 + 5 eye examination

Glaucoma NZ recommends the 45 + 5 glaucoma eye examination.

  • From the age of 45 years, have an eye check examination – even if you haven’t had any eye problems
  • If the examination is normal you can repeat it every 5 years
  • If the examination shows any signs of glaucoma your eye specialist will advise you on a course of treatment 

Diagnosis

Early detection through regular check-ups is the key to protecting your vision from damage caused by glaucoma.

A complete eye exam will include several tests to detect glaucoma. Common tests include taking measurements of:

  • the inner eye pressure
  • the shape and colour of the optic nerve
  • the field of vision
  • the angle in the eye where the iris meets the cornea
  • the thickness of the cornea.

Treatment

Although glaucoma cannot be cured, it can usually be stopped from getting any worse. By quitting smoking, exercising regularly and eating a balanced diet, you can help to slow the progression of the condition.  

Medicated eye drops are the most commonly used treatment. They reduce the pressure in your eye by helping the fluid drain from your eye or by reducing the amount of fluid produced. Read more about eye drops for glaucoma.

Another treatment option is laser surgery to make it easier for fluid to drain from your eye. The lasers used for glaucoma are quite different from the LASIK surgery used to correct vision. There are two types of laser surgery for glaucoma:

  • Laser trabeculoplasty: this is a safe, easy treatment for most patients with glaucoma. Read more about laser trabeculoplasty.
  • Laser iridotomy: this is performed usually for patients with narrow angles or angle closure glaucoma. Read more about laser iridotomy.

Complementary or alternative treatments are not usually recommended in the treatment of glaucoma due to a lack of quality evidence that they are effective. Examples of alternative therapies include vitamins, ginkgo biloba, meditation and acupuncture. Read more about alternative glaucoma therapies.

Learn more

Range of topics Glaucoma NZ
Glaucoma Best Health UK
Glaucoma section  New Zealand Association of Optometry
Read more Best Health UK
Glaucoma and ginko biloba Glaucoma NZ

Credits: Glaucoma NZ, Updated to Health Navigator NZ April 2014. Image courtesy of Wikimedia Commons The Eyes Have It.. Last reviewed: 06 Aug 2018