Glaucoma

Glaucoma is an eye disease in which progressive damage to your optic nerve can result in blindness if not treated in time. Often there are no symptoms, so get regular eye checks from the age of 45 years.

Key points

  1. Glaucoma is one of the main preventable causes of blindness in New Zealand. More than 1 in 10 people over 80 years of age have glaucoma.
  2. Because there are often no symptoms, damage can occur for many years before diagnosis.
  3. If you are over 45 years of age, get your eyes checked every 5 years by an optometrist, or every year if you are over 60 years. These checks help identify glaucoma at an early stage before too much vision has been lost.
  4. Seek urgent medical advice if you experience sudden changes in your vision or pain in your eye.
  5. Treatments are available to help prevent further damage. With proper care, less than 2% of patients with glaucoma will go blind. 

(Source: What is glaucoma? EyeSmart, Academy of Ophthalmology)

What are the causes of glaucoma?

Fluid is produced in the front of your eye and produces pressure within your eye. When the pressure is too high within your eye, the optic nerve becomes damaged, leading to loss of vision. In some people, damage can occur with pressure within the normal range and is largely thought of a problem in pressure sensitivity. The causes of glaucoma are largely unknown at present; however, there is strong evidence for a genetic cause. 

How does glaucoma cause vision loss?

Vision is lost due to damage to the optic nerve, which is the ‘cable’ that connects your eye to your brain. This damage is irreversible, so glaucoma must be detected early to stop progressive damage leading to blindness. 

Who is most at risk of glaucoma?

You are at an increased risk of glaucoma if you:

  • are older than 40 years
  • have a family history of glaucoma
  • are either short-sighted or long-sighted
  • have a history of migraine or Raynauds syndrome
  • use cortisone or steroids
  • have a previous eye injury.

If you fit into one of these risk groups, see an eye care professional (known as an optometrist or ophthalmologist) at least every 1 to 2 years for an eye check.

There are optometrists who have advanced training in glaucoma. Ophthalmologists are medical doctors who have completed training in managing eye conditions. Fellowship-trained glaucoma specialists are ophthalmologists who have conducted additional training in managing glaucoma and performing glaucoma surgery.

What are the symptoms of glaucoma?

Glaucoma mainly has no symptoms, except in advanced glaucoma or in people with acute angle closure glaucoma. Contrary to previous assumptions, you do not develop a darkening of vision in your peripheral vision. Instead, you usually experience a ‘jack in a box’ perception of the sudden presence of objects missed from your peripheral vision.

When to seek urgent medical help

In cases of acute angle closure glaucoma and some other causes of glaucoma, you may develop rapid onset of these symptoms:

  • blurred vision
  • seeing coloured halos around lights
  • redness of your eye
  • nausea or vomiting
  • pain in your eye.

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

What can I do to protect my eyes from glaucoma?

Early detection through regular check-ups is the key to protecting your vision from damage caused by glaucoma. Glaucoma is easy to treat when found early.

  • If you are in any of the higher risk groups above, have an eye check at least every 1 to 2 years.
  • For everyone else, have a regular eye check from the age of 45 (see the 45 + 5 recommendations below).
  • If you are over 60 years of age, get your eyes checked every year.

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.

How is glaucoma diagnosed?

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

  • your vision
  • your inner eye pressure (intraocular pressure)
  • the appearance of the optic nerve
  • your field of vision (this indicates the function of the optic nerve)
  • the drainage angle (where fluid drains out of your eye)
  • the thickness of your cornea
  • the structure of your optic nerve and retina (OCT).

What is the treatment for glaucoma?

Although glaucoma cannot be cured, it can usually be stopped from getting worse. Things you can do to slow the progression of glaucoma include to:

  • stop smoking
  • exercise regularly
  • eat a balanced diet
  • see an optometrist or eye specialist regularly for advice and monitoring
  • apply your eye drops everyday as directed.

Eye drops

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.

Laser treatment

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 refractive surgery used to correct vision and are usually clinic-based procedures. The types of laser surgery for glaucoma include the following:

  • Laser trabeculoplasty: This is a safe, easy treatment for most people with glaucoma. Read more about laser trabeculoplasty.
  • Laser iridotomy and laser iridoplasty: This treatment is most often used if you have narrow angle 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, meditation and acupuncture. Read more about alternative glaucoma therapies and glaucoma and gingko biloba

Surgery

If you have progressive glaucoma despite medical and laser therapy, or have significant side effects from medical therapy, surgery may be the only form of treatment for controlling the pressure in your eyes.

Most surgeries are day procedures, which means you don't need to stay in hospital after the procedure. The procedures can range between 10–90 minutes and may be done in conjunction with cataract surgery. Most procedures are done under local anaesthetic and you do not need to fast (not eat) for them. This is similar to having your teeth filled by your dentist.

Surgical options include the following:

  • filtration surgery (trabeculectomy and deep sclerectomy)
  • drainage tube
  • cyclodiode laser
  • minimally invasive glaucoma surgery (MIGS)
  • XEN
  • iStent
  • Hydrus
  • micropulse laser.

Read about these surgical options.

Learn more

Fact sheets on different glaucoma topics Glaucoma NZ
Glaucoma Best Health UK
Glaucoma section  New Zealand Association of Optometry
Read more Best Health UK
Minimally invasive glaucoma surgery International Glaucoma Association
Glaucoma Australia

Reviewed by

Dr Perumal works in private practice at the Eye Institute and Auckland District Health Board. She has previously undertaken a prestigious Glaucoma Fellowship at Manchester Royal Eye Hospital, UK which includes expertise in advanced glaucoma surgery, minimally invasive glaucoma surgery and non-penetrating glaucoma surgery. She is a senior lecturer at the University of Auckland and is actively involved in teaching junior doctors and research.
Credits: Health Navigator Editorial Team .