An Optic Nerve Disease

Glaucoma is the leading cause of blindness in North America. A disease of the optic nerve, which supplies visual information to the brain, glaucoma damages nerve fibres, causing blind spots and vision loss. Glaucoma is usually the result of abnormally high pressure inside the eye.


Glaucoma is a chronic disease, which may be controlled but not cured. The goal is to lower the eye pressure to prevent vision loss. Dr. Conlon will recommend treatment if necessary, consisting of eye drops, laser treatment, or surgery.

Glaucoma FAQ

Q: What is glaucoma?

A: Glaucoma is an eye disease, resulting from optic nerve damage, which left untreated causes irreversible vision loss. Often this damage results from inadequate fluid drainage, causing your eye’s internal pressure to rise above normal levels. The most common type of glaucoma is what is known as primary open angle glaucoma, which occurs when drainage canals become blocked. Less often, angle closure glaucoma may occur, which happens when the entrance to the drainage canal is too narrow. Although, even people with regular eye pressure can sometimes exhibit optic nerve damage, which is called normal tension glaucoma.

Q: What causes glaucoma?

A: Injury, infection or tumors are all known to raise eye pressure, labelled secondary glaucomas, but the cause of eye drainage blockage without such issues is unknown. We do know that once this blockage occurs, fluid builds up within your eye, causing damaging pressure on the optic nerve. This pressure compromises the delicate optic nerve’s blood vessels and nerve fibers, causing vision loss. Cases of glaucoma that appear even with normal eye pressure are likely caused by poor blood flow to the optic nerve.

Q: Who is at-risk for glaucoma?

A: More than 400,000 Canadians have glaucoma, occurring most commonly amongst individuals 40 years of age or older. Besides age, other risk factors include: elevated intraocular pressure (IOP), family history of glaucoma, preexisting optic nerve conditions, background of African descent, high myopia (nearsightedness), diabetes, and high blood pressure.

If you are deemed at-risk or are over the age of 35, regular eye examinations are recommended as a preventative measure against glaucoma.

Q: How does glaucoma harm vision?

A: The optic nerve consists of more than one million nerve fibres, and is located at the back of the eye, connecting the retina to the brain. The optic nerve transmits the eye’s visual information to the brain.Glaucoma results in nerve fibre damage, thus causing a decrease in the amount and/or quality of the information sent, which results in vision loss.

Q: Does glaucoma cause blindness?

A: Although glaucoma is one of the leading causes of blindness in Canada, with early detection, it can be managed to avoid little or no increased vision loss. Untreated, glaucoma will first affect peripheral and then central vision, with blindness as a potential later-stage result. For those dealing with glaucoma, early intervention is key to minimizing vision issues.

Q: What glaucoma signs should I be aware of?

A: Glaucoma signs and symptoms vary depending on the disease type. Unfortunately, the most common form, primary open-angle glaucoma, develops without warning signs. Typically, sufferers only become aware of the condition once sight loss has already occurred. Acute-angle closure glaucoma develops more rapidly and so is easier to detect. Symptoms of this glaucoma type include blurred vision, seeing halos or coloured rings around lights, and painful, red eyes. The hidden nature of glaucoma highlights why it is so important to receive regular examinations if you are high-risk for the disease.

Q: How is glaucoma detected?

A: Comprehensive eye examinations test for glaucoma. Specifically, tonometry is the technique used to measure IOP. Other aspects include checking optic nerve health and measuring field of vision. Dr.Conlon will request regular examinations if you display one or more risk factors.

Q: How is glaucoma treated?

A: It is important to note that glaucoma is a disease that, at least presently, can be controlled but not cured. The usual course of treatment is an eye drop regiment, but laser treatment or surgery may also be required. Ongoing examinations at a frequency deemed appropriate (annual, three or six month intervals) will allow Dr. Conlon to monitor changes and tailor treatment accordingly.

Q: Can treatment restore vision?

A: Prevention is integral to glaucoma treatment, because as of yet, there is no means for restoring vision lost to the disease. Low-vision rehabilitation programs, are options for the severely visually impaired.

Q: Can glaucoma be prevented?

A: There are no known preventative measures for glaucoma. Maintaining a healthy lifestyle and avoiding serious eye injuries may prove beneficial. Undergoing regular comprehensive eye exams, allowing for early detection and treatment, is the best prevention for glaucoma and resulting vision loss.