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Who is at Risk of Glaucoma?

Risk Calculator coming soon.

The majority of patients with glaucoma will not experience symptoms in the early stages of the disease. Glaucoma is known as the “silent thief of sight” because it affects side vision before central vision. A loss of peripheral vision is not readily noticeable in day-to-day life.

The only way to know if you have glaucoma is to see your optometrist or ophthalmologist for a full examination. Optometrists have both the skills and equipment to screen for glaucoma, and are usually the first port of call to find out if you may have glaucoma.

Generally, two in 100 Australians will develop glaucoma in their lifetime and usually there are no apparent symptoms in the early stages of the disease. Click here to learn more about glaucoma.

Although anyone can get glaucoma, some people have a higher risk - they are those with:

  • A family history of glaucoma (see below)
  • High eye pressure
  • Age over 50
  • African or Asian descended ethnicity
  • Diabetes
  • Short or long sightedness
  • A previous history of eye injury
  • Past or present prolonged use of cortisone drugs (steroids)
  • Migraine
  • High or low blood pressure

Abridged: NHMRC Guidelines, 2010

It is recommended that people have a regular optic nerve check from age 50 and from age 40 for those of African or Asian descent. Those with a positive family history should be checked from age 35 as they have a significantly increased risk. Most people are recommended to have an eye check for glaucoma every 2-3 years or when advised by their eye health professional.

Q: What does testing for glaucoma entail?
A: The following tests will be completed by your optometrist or ophthalmologist to assess your risk for glaucoma.

  • Intraocular pressure (IOP) measurement
    The pressure within the eyeball. In glaucoma, the pressure in the eye is often higher than normal. Glaucoma treatment currently focuses on lowering the intraocular pressure of the eye.

  • Assessment and photography of the optic nerve head
    The optic nerve head is where the optic nerve inserts into the eyeball, which in turn transmits visual information from the eye to the brain. In glaucoma, the optic nerve head begins to demonstrate significant excavation as the individual nerve fibres within it begin to die.

  • Assessment of the retinal nerve fibre layer (RNFL)
    There are a number of ways the health of retinal structures can be assessed. Modern technology like optical coherence tomography (OCT) can non-invasively and accurately measure the thickness of the nerve fibres supplying the optic nerve head. In glaucoma, the retinal nerve fibre layer (RNFL) becomes thinned, either in certain sectors or diffusely.

  • Assessment of your peripheral vision (visual field testing)
    Visual fields are a formal measurement of the peripheral vision. In this test, the patient is instructed to look straight ahead and to press a button when they notice lights in their peripheral vision. Visual field testing is very subjective and initially can be performed unreliably due to excessive eye movements and/or false responses. Performance improves significantly with repeat testing, and it may take many tests for a patient to become confident with visual fields.

  • Assessment of the anterior chamber angle
    The anterior chamber angle is a representation of the “drainage” pathway of fluid leaving the eyeball. If the anterior chamber angle is narrow, then a patient may be more prone to having high intraocular pressure. The anterior chamber angle is often assessed using gonioscopy, in which a special lens is placed on the surface of the eye after it has been numbed with anaesthetic eye drops.

Intraocular pressure is sometimes incorrectly thought to be the only sign of glaucoma. In reality, all of the abovementioned tests are used by your optometrist to establish your risk for developing glaucoma. Not uncommonly, your optometrist may ask you to come back for multiple visits to establish accurate baseline measurements on these tests, and to more accurately monitor for changes. Glaucoma is often a slowly-progressive disease; for this reason, it can sometimes take many years of monitoring before a definitive diagnosis of glaucoma can be made.

Early assessment by an optometrist, particularly if you have a family history of glaucoma, is critical in detecting glaucoma and commencing treatment in a timely manner. There are different types of treatment for glaucoma, and this is usually initiated by an ophthalmologist (eye doctor). Many optometrists are also qualified to begin treatment and monitor your glaucoma. It is standard practice for both an optometrist and ophthalmologist to participate in the care of your eyes when you have glaucoma.

Some rarer forms of glaucoma have a faster onset. In angle-closure glaucoma, the intraocular pressure of the eye can become rapidly and markedly elevated. In this situation, you may experience severe eye pain, eye redness, blurred vision, and haloes around lights. Headache, nausea and vomiting may follow. This is an eye emergency requiring urgent attention by a trained ophthalmologist to prevent permanent loss of vision. In chronic forms of angle-closure glaucoma, patients may experience these symptoms intermittently and usually at night prior to a full-blown attack. 

Glaucoma in families

In many cases, glaucoma is an inherited (genetic) disease that is passed on within families, and there is an increased risk with closer relatives. Those with a direct relative (child, sibling, or parent) with glaucoma have a much higher risk of developing glaucoma – 1 in 4 may develop glaucoma in their life time. Therefore, regular eye examinations for this group should commence at least 10 years earlier than the age of onset of glaucoma in their affected relative. Early detection of glaucoma means preventing vision loss.

In the recent TARRGET (Targeting At Risk Relatives of Glaucoma patients for Early diagnosis and Treatment) study, the results indicate that the risk of developing glaucoma among immediate relatives is higher when a person in the family has reached severe glaucoma. This shows the importance of patient education and screening for family members of individuals with advanced glaucoma. In addition, the lack of awareness about the disease was highlighted, as one third of the first-degree relatives of glaucoma patients had never had their eyes checked before the study.

To learn more, click on the following 2 articles:

TARRGET report - June 2016 
TARRGET report - January 2017 update 

Research has also identified a number of genes which are linked to congenital (childhood) glaucoma, and adult-onset primary open angle glaucoma (POAG). The situation is complex and it is likely that multiple mutations in more than one gene may be involved, given that POAG is likely to be inherited as a complex trait. As such, current genetic screening for adults at-risk of glaucoma is not yet available. However, there is evolving evidence for genetic screening via a buccal (cheek or mouth) swab.

Given that research findings strongly support that glaucoma runs in families, it is very important for all patients diagnosed with glaucoma to alert first-degree relatives, and have the conversation to prompt them to have regular comprehensive eye examinations to screen for glaucoma.

Having a family history of glaucoma puts someone at greater risk of developing glaucoma themselves. Direct family members (parents, siblings and children) of a person with glaucoma have an almost 1 in 4 chance of developing glaucoma in their lifetime.

If you have a family member with glaucoma click here.

If you have glaucoma and are concerned about your family members, click here.