Diseases generally tend to have telltale symptoms that clearly let a person know if he or she has an underlying medical condition that requires treatment.
However, the onset of some diseases, like glaucoma, is subtler. A person who contracts glaucoma won't feel any pain, but their vision is slowly but surely reduced over time, potentially resulting in total blindness if left untreated, said Dr. Tanya Sitter, an optometrist who works in Sundre and Olds. World Glaucoma Week was recently observed from March 6-12.
Glaucoma is a disease that causes damage to the optic nerve, which connects the eye to the brain, and causes a loss of peripheral ó or side ó vision. Although both eyes are usually affected, there are times when only one eye suffers damage. The trouble with glaucoma is people who require treatment often don't realize it until they have already begun to lose their vision, she said.
"You can lose up to 75 per cent of your peripheral vision before you're aware of the condition."
A person suffering from glaucoma might only notice a problem once their peripheral vision has been reduced to tunnel vision. The majority of the types of glaucoma are completely painless, but the damage caused to the optic nerve and the ensuing loss of vision is irreversible ó once a glaucoma sufferer's vision is gone, it's gone forever, she added.
Experts are not entirely certain what causes the condition, as there are a number of biological mechanisms involved, but in short, either an overproduction of fluid in the eyeball, or conversely a lack of drainage of the fluid, results in damage to the optic nerve. The overproduction of fluid or the lack of adequate drainage can be a result of the eye's anatomy or trauma. Additionally, other health conditions like diabetes and high blood pressure can increase the risk of glaucoma, she said, adding the condition is also more common than people might think.
"I definitely see patients with glaucoma regularly," she said.
"It's probably one of the most common things we see that people were completely unaware that they had a problem to begin with."
According to the Glaucoma Research Society of Canada, the condition affects more than 400,000 Canadians and some 67 million people worldwide.
Glaucoma can develop at any age ó even babies can get it ó but the condition is much more common after the age of 40, said Sitter.
The only way to protect one's vision from glaucoma is to ensure he or she is getting a routine eye exam from an optometrist or an ophthalmologist. In the absence of any other existing factors, a person should visit his or her eye doctor every two to three years before the age of 65 and annually after that. However, if there are additional risk factors like recent trauma, family history, diabetes and high blood pressure, a person should visit an optometrist more often, she said.
"The main message is to get your eyes tested even if you see well and don't think you have any problems."
The most common treatments for glaucoma are either the daily application of eye drops or laser eye surgery. While any optometrist can treat glaucoma, any surgical intervention will require the services of an ophthalmologist, she said.
Although a visit to the optometrist might leave some people concerned about the cost ó especially if they don't have coverage ó Sitter pointed out that in Alberta, appointments for any medically necessary services or emergencies such as pink eye or injuries caused by something like bits of shrapnel are fully covered for any age group by provincial health care.
Additionally, Albertans under the age of 19 and over the age of 65 can have the cost of getting their eyes examined covered by the province, she said.
