Be On the Alert for Signs of Glaucoma

According to the Glaucoma Research Society of Canada, more than 325,000 Canadians over the age of 40 have glaucoma, and many of those people aren't aware that they have the condition. The incidence of glaucoma is expected to soar as the baby boomers age. Early detection is key to preventing loss of vision.

What Is Glaucoma?

Your eye is about the size of a golf ball. It is filled with a clear, jelly-like fluid that keeps it round. The eyeball is constantly being filled with new fluid, and the old fluid drains away at the same rate. But if too much fluid is produced or not enough can drain, pressure builds up in the eye. Left untreated, this excess pressure will damage the nerves that let us see. This can result in loss of sight and eventually blindness. Glaucoma sometimes has a known cause, such as an eye injury, cataracts, scar tissue, or the use of certain medications. But in most cases, the cause is unknown.

In about 5% of cases, glaucoma strikes suddenly, with severe pain and a sudden vision problem. This is called acute or closed-angle glaucoma. In most cases, pressure builds up gradually, damage progresses slowly, and there is no pain. This is called chronic or open-angle glaucoma.

What Are the Signs of Glaucoma?

Glaucoma is called "the sneak thief of vision" because in most cases, symptoms aren't noticeable until damage is already done. The chronic form affects peripheral (side) vision first. But this loss of sight is often so gradual that the person doesn't notice until central vision is affected. There may be other subtle symptoms, such as blurred vision or rainbow-colored rings around lights. 

In the acute type of glaucoma, symptoms are severe and sudden. Permanent loss of vision can occur within hours. The symptoms of acute glaucoma include redness of the eye, severe pain, headaches, nausea, sudden noticeable change in vision, and colored rings ("halos") around lights. Acute glaucoma is a true medical emergency. If you or a loved one has the above symptoms, you should see a health care practitioner immediately.

It is important to catch and treat glaucoma early. People over 40 should have their eyes checked every year by an eye care professional, who will test the pressure in your eye, look at the inside of your eye with a special instrument, and test your vision to detect any small changes that would suggest glaucoma. The tests for glaucoma are painless.

How Is Glaucoma Treated?

Unfortunately, affected vision cannot be restored. But medical treatment can prevent further damage. The goal of glaucoma treatment is to reduce the pressure inside the eye. Some medications cut down on the amount of fluid the eye produces; others encourage a better flow of fluid out of the eye. Some drugs are taken in eye drop form, others as pills. It is very important to take medication as directed.

People with the sudden, acute form of glaucoma usually need immediate surgery. And in some of the slower, chronic cases, the doctor eventually recommends surgery if medication fails to control the pressure well enough, or medicines are causing unacceptable side effects, making surgery the better alternative. Glaucoma surgery is relatively safe and painless, usually requiring only a short hospital stay. Today, laser surgery can make the procedure even shorter and easier.

Remember: glaucoma can be managed if detected early enough! So a glaucoma test should be a regular part of your annual physical examination. 

For More Information

The Glaucoma Research Society of Canada offers online information and resources for consumers.

The Canadian Glaucoma Society and the Canadian Ophthalmological Society join to offer online consumer information and resources about the diagnosis and treatment of glaucoma, including the brochure "Glaucoma: It Can Take Your Sight Away."

The Canadian Association of Optometrists also offer information about glaucoma in their online Eye Health Library.