Understanding glaucoma

As May is Vision Health Month — a time to emphasize the importance of eye health and encourage Canadians to prioritize their vision — this is the perfect opportunity to spread awareness about glaucoma, a group of eye diseases that causes vision loss for millions around the world.

At UHN, Dr. Matthew Schlenker, an esteemed physician who leads the Glaucoma Clinic at the Donald K. Johnson Eye Institute, provided answers about glaucoma, including those about its causes, and treatments offered right here at UHN.

Glaucoma is a group of eye diseases that cause damage to the nerve which connects the eye to the brain. It is sensitive to eye pressure, and in most cases the patient does not have any symptoms of high eye pressure. As the world’s leading cause of irreversible blindness, it steals people’s gift of sight slowly, gradually, and without warning.

Due to often exhibiting no symptoms in its early stages, glaucoma is frequently referred to as the “silent thief of sight.” Once it has been discovered and diagnosed, permanent vision loss may have already occurred. If left untreated, it can progress and cause permanent visual impairment and blindness.

While people with the most common form of glaucoma don’t experience any symptoms until the later stages of the disease, symptoms can vary depending on the type and stage of the condition and may include:

Glaucoma is caused by damage to the optic nerve. It can occur without any apparent cause, but many factors can affect the condition. The most important of these risk factors is elevated intraocular pressure, with consequent damage to the optic nerve leading to vision loss or blindness.

The optic nerve is crucial to our vision — sending information collected by our eyes to the brain to be translated into sight. However, its collection of fibers can be tenuous and mechanically weak, making it vulnerable to damage.

More than 400,000 people in Canada and 78 million people around the globe experience vision loss due to glaucoma. These numbers may be much higher since the disease progresses slowly, and people may not realize they have it until major damage has already occurred. As our population ages and lives longer, the urgent need for new treatments and greater access to care for glaucoma will only intensify.

Early detection is of primary importance, as early signs of the condition can be missed without regular eye tests at least every two years. If you experience symptoms that come on suddenly — including a bad headache and severe eye pain—you need treatment as soon as possible. It is recommended that you visit an emergency room or contact an ophthalmologist immediately in such cases.

Damage to the optic nerve is irreversible, so there is no cure for glaucoma. This makes it critical to have regular checkups and take any prescribed medication as directed.

The objective of any treatment is to reduce intraocular pressure and slow down the effects of the condition. Treatments include:

The glaucoma service at the Donald K. Johnson Eye Institute, UHN, is a national leader in both clinical care and research, treating more than 5,000 patients annually with the latest technology in optic nerve imaging and visual fields. The service brings together an exceptional team of physicians, surgeons, researchers, and fellows that makes it a leading force in ophthalmology. Outstanding care is provided to patients with glaucoma, including special expertise in laser treatments and surgical techniques, such as the use of glaucoma drainage devices like the Ahmed Glaucoma Valve. If a Glaucoma patient is having cataract surgery, it is often an opportunity to perform minimally invasive glaucoma surgery concurrently to stabilize the glaucoma. The team is relentless in the pursuit of new treatments and, hopefully, one day a cure that will transform people’s lives.

For more information about the referral process, please get in touch with the Donald K. Johnson Eye Institute at [email protected].