Who is at Risk of Glaucoma?
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:
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 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:
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.