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All About Glaucoma: Everything You Need To Know

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Glaucoma is one of the major causes of vision loss in North America. But despite the fact that it’s quite common, few people know much about it until they’ve been diagnosed, and at that point, they may have already lost a good portion of their vision.
By educating ourselves about glaucoma and similar diseases, we can take a more proactive stance on our eye health. 

What is Glaucoma?

Glaucoma is an eye disease that causes permanent cumulative damage to the optic nerve. This nerve is responsible for transmitting signals from the retina to the brain. If it sustains too much damage, we can experience vision loss, which is precisely what happens with glaucoma.
Sometimes, the optic nerve is damaged by something called intraocular pressure. However, this isn’t always the case. Sometimes the optic nerve becomes damaged without an increase in intraocular pressure. Doctors don’t quite know what causes the damage in these cases.
Perhaps the most dangerous element of glaucoma is its stealth. Optic nerve damage usually occurs very slowly over a period of years. In most cases, this damage is so gradual that people don’t even notice the changes to their vision until they’ve lost a good portion of their sight. Unfortunately, once glaucoma has damaged the optic nerve, the damage cannot be undone.

dark fuzzy landscape
A simulation of what advanced glaucoma may look like.

The best and most effective way to reduce your chances of vision loss is by seeing your optometrist on a regular basis for testing. 

Types of Glaucoma

Each type of glaucoma works a little bit differently. But before you can understand the mechanics of glaucoma, we first need to explore a little bit of the eyes’ anatomy. 
Eye anatomy diagram
There is a space between your crystalline lens and your cornea called the anterior chamber. Part of the eye called the ciliary body secretes a liquid called the aqueous humour, which flows through a small space between the lens and the iris, and out into the anterior chamber. Eventually, the aqueous humour will flow back out of the chamber through ducts.
Intraocular pressure is a metric that expresses how much of the aqueous humour is filling the anterior chamber. 

Open-Angle Glaucoma

Open angle glaucoma diagram
Open-angle glaucoma is the most common form of the disease, occurring when there’s enough space between the iris and the lens to allow the aqueous humour to flow through, but IOP keeps rising. The climbing pressure is due to an issue with the drainage ducts in the anterior chamber.
If open-angle glaucoma is caught early, it can be managed to limit further vision loss.


Angle-closure glaucoma diagram
Angle-closure glaucoma is unique from the other types of glaucoma because it comes on very suddenly. While other types of the disease develop with few noticeable symptoms, this one is accompanied by severe and rather violent indicators, including:

  • Nausea
  • Vomiting
  • Extreme eye pain
  • Headache
  • Excessive tears
  • Blurry vision
  • Glare or halos around lights

This condition develops when the space between the iris and the lens suddenly closes, preventing the aqueous humour from flowing properly without the ability to drain, the aqueous humour continues to fill the eye, rapidly building eye pressure and damaging the optic nerve.
Angle-closure glaucoma is a medical emergency. If you experience these symptoms, it’s vital that you seek immediate medical attention.


Medical science is always changing, and we’re learning more about the human body every single day. However, sometimes the body does things we just don’t understand. This is what happens with normal-tension glaucoma. 
In cases of normal-tension glaucoma, the angle between the iris and the lens is wide enough to allow the aqueous humour to flow through, and the drainage ducts appear to be working properly. Still, for some reason, the optic nerve continues to sustain cumulative damage. Doctors are not yet sure what causes the damage. However, the condition can be managed once it has been diagnosed. 


Most people associate glaucoma with seniors, but it is possible for children to suffer from glaucoma. Childhood glaucoma or congenital glaucoma develops in children whose eyes did not develop properly. As a result, the aqueous humour cannot drain effectively, causing their IOP to increase.
Children with congenital glaucoma may have:

  • Enlarged eyes
  • Cloudy corneas
  • Sensitivity to light
  • Excessive tears

Most cases of congenital glaucoma are diagnosed within the child’s first year of life. This condition can be managed with surgery, medication, or a combination of the two. 

Risk Factors

Like most diseases, some people are more likely to develop glaucoma than others. Of course, genetics and family history a factor. Other factors include:

  • Age, specifically when over the age of 60.
  • Ethnic background, including Carribean, African, Latino, and Asian lineage
  • Trauma to the eye, such as injuries or surgeries
  • Long-term use of corticosteroids
  • Conditions affecting blood flow, including diabetes, high blood pressure, or low blood pressure

When Does Glaucoma Develop?

Generally speaking, your risk of glaucoma does increase as you get older. However, that’s not to say that glaucoma will not develop in someone who is 39, or even 21. Unfortunately, glaucoma can develop at any time, so it’s crucial that you stay vigilant with eye exams. It is never too early to test for glaucoma.

Should I Be Worried About Glaucoma?

I don’t like clickbait. I actively try to avoid scare tactics as a means of getting patients’ attention. So I wouldn’t necessarily say that you should be worried about glaucoma. But you should absolutely be aware of glaucoma. 
The reality is that, unless glaucoma is diagnosed early, it results in significant irreversible vision loss. By seeing your optometrist regularly and undergoing glaucoma testing, you can significantly reduce your risk of profound vision loss. Even more encouraging, technology is advancing at breakneck speed. With the right equipment, optometrists can diagnose glaucoma years earlier than they would have done previously.

Written by Dr. Kevin Hesterman

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