Australia is amongst the best in the world for the diagnosis and treatment of potentially blinding glaucoma but 50 percent of Australians with the eye disease still remain undiagnosed.
Glaucoma is commonly referred to as ‘the sneak thief of sight’. It irreversibly destroys vision silently and gradually, starting with the side vision. Fortunately, if detected early enough it can be arrested or at least slowed by appropriate treatment.
Worldwide figures show glaucoma remains undiagnosed in as many as 85 percent of an estimated 65 million people with the disease. It is even higher in India with 90 percent undiagnosed while the Asian region accounts for between 60 to 80 percent of people yet to be diagnosed. The USA matches Australia with 50 percent of people unaware they have the disease. While Australia is a leader in the diagnosis and treatment of glaucoma, 50 percent of Australians or about 150,000 people are still unaware they have glaucoma, which is still alarming. Around the globe the eye disease that has blinded 10 million people, according to a 2005 report. Australia has 7000 residents blinded from glaucoma.
WHO IS AT RISK?
Although anyone can get glaucoma, some people have a higher risk. These include:
- family history of glaucoma
- short sightedness (myopia)
- eye injuries
- blood pressure
- past or present use of cortisone drugs (steroids)
People in these groups should have their first eye check no later than the age of 35. For most people, it is recommended to have an eye check for glaucoma by the age of 40.
CAN GLAUCOMA BE TREATED?
Although there is no cure for glaucoma it can usually be controlled and further loss of sight either prevented or at least slowed down.
Eye drops – these are the most common form of treatment and must be used regularly. In some cases pills are prescribed. The drops can be varied to best suit the patient and the type of glaucoma.
Laser (laser trabeculoplasty) – this is performed when eye drops do not stop deterioration in the field of vision. In many cases eye drops will need to be continued after laser. Laser does not require a hospital stay.
Surgery (trabeculectomy) – this is performed usually after eye drops and laser have failed to control the eye pressure. A new channel for the fluid to leave the eye is created.
WHAT ARE SOME OTHER FORMS OF GLAUCOMA?
Chronic (primary open-angle) glaucoma is the most common form of this disease. However, other forms occur:
Low-tension or normal tension glaucoma: Occasionally optic nerve damage can occur in people with so-called normal eye pressure. This form of glaucoma is treated in the same manner as open-angle glaucoma.
Acute (angle-closure) glaucoma: Acute glaucoma is when the pressure inside the eye rapidly increases due to the iris blocking the drain. An attack of acute glaucoma is often severe. People suffer pain, nausea, blurred vision and redness of the eye. Immediate medical help should be sought. If treatment is delayed there can be permanent visual damage in a very short time. Usually, laser surgery performed promptly can clear the blockage and protect against visual impairment.
Congenital glaucoma: This is a rare form of glaucoma caused by an abnormal drainage system. It can exist at birth or develop later. Parents may note that the child is sensitive to light, has enlarged and cloudy eyes, and excessive watering. Surgery is usually needed.
Secondary glaucomas: These glaucomas can develop as a result of other disorders of the eye such as injuries, cataracts or eye inflammation. The use of steroids (cortisone) has a tendency to raise eye pressure and therefore pressures should be checked frequently when steroids are used.
The major concern throughout the world is that glaucoma blindness can be largely prevented if the disease is detected early enough and treated. It is so critical for people to be aware of the need for an eye check-up every two years or more regularly if you have a family history of glaucoma or diabetes, high blood pressure or have suffered from an eye injury.
With studies in recent times about the relationship between the corneal thickness and intraocular pressure, your optometrist may use a pachymeter during testing. A thicker cornea may present the pressure to be higher than the true intraocular pressure. The reverse case can also occur where a thinner cornea presents a lower pressure and may mask a person who in fact has glaucoma. Assessment of the optic nerve and field of vision as well, plays a part in diagnosis.
Ocular Coherence Tomography (OCT) is useful in early detection of glaucoma. It is a non-invasive imaging technique used to scan the layers of the retina and optic nerve. It is able to assess the density of retinal ganglion cells (neutrons which receives visual information from photoreceptors) and detect loss of these cells. Early detection could potentially prevent a person from losing their sight.
Awareness is the only way we can hope to limit the impact of this dreadful, but easily treated disease. There is no need to lose your sight to glaucoma. Often, people who don’t have regular eye check-ups only find out they have the disease after they have lost considerable peripheral vision. This can have negative consequences including losing your driving licence or suffering injuries caused by falls or hitting into unseen obstacles.
A collaboration between the Prince of Wales Hospital Ophthalmology Department and the Centre for Eye Health has led to the establishment of the Glaucoma Management Clinic at UNSW. This clinic was the first of its kind conceived in Australia. To raise awareness about the disease during Glaucoma Australia’s Glaucoma Awareness Week, the UNSW School of Optometry and Vision Sciences and the Centre for Eye Health are hosting a B.I.G. Breakfast on Wednesday 14th March, 8 am to 10:30 am on campus.
Glaucoma is a disease that irreversibly destroys eyesight. You can’t get back what vision you have lost to glaucoma. The only way to detect it is to have regular eye check-ups with your optometrist at least every two years.
For further information, see your eye care practitioner.