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  • Prairie Eye Care

How Glaucoma Diagnostic Tests Can Detect Early Signs

Glaucoma is an eye condition that damages the optic nerve and can cause vision loss in those affected. In fact, glaucoma is one of the leading causes of blindness worldwide. Most of the time, symptoms of glaucoma don't present themselves right away. This means you could have the condition without even knowing it. Unfortunately, damage from glaucoma can't be reversed. Early detection through regular comprehensive eye exams is key to diagnosing glaucoma and preserving your vision.  

What Is Glaucoma?

Glaucoma is a group of eye diseases that can lead to vision loss and blindness by damaging the optic nerve at the back of the eye. This is the nerve that carries messages from the eye to the brain, which allows us to see. Damage occurs when fluid builds up, causing an increase in eye pressure. There are a few different types of glaucoma, the most common being open-angle glaucoma and closed-angle glaucoma. Open-angle glaucoma accounts for around 90% of all cases and is a lifelong condition that progresses over time when left untreated. Closed-angle glaucoma occurs when the fluid in the eye is suddenly blocked, causing a quick rise in pressure. Closed-angle glaucoma is considered a medical emergency and requires immediate treatment.  

What Are Some Symptoms of Glaucoma?

As mentioned, symptoms of open-angle glaucoma don't often occur in the early stages. Often there may be no symptoms until the condition has become advanced. Some symptoms that may eventually present themselves are:

-blurry vision

-patchy spots in your peripheral vision

If you experience symptoms that occur suddenly you may be suffering from closed-angle glaucoma. These might include:

-eye redness or eye pain


-severe headache

-seeing coloured halos or lights

Closed-angle glaucoma requires immediate treatment and you should call your optometrist or visit the emergency room right away.  

Which Diagnostic Tests Are Used To Screen for Glaucoma?

While there is no cure for glaucoma, when caught early the disease can be treated and its progression can be slowed. Comprehensive eye exams are the best way to diagnose this condition. To screen for glaucoma your eye doctor will perform several diagnostic tests including:


This test uses eye drops and a device called a tonometer to measure the inner pressure of the eye. Eye pressure is unique to each person, although most glaucoma cases are diagnosed with pressure exceeding 20 mm Hg (millimetres of mercury). High pressure in the inner eye is often one of the first signs of glaucoma.


This is a visual field test that determines your complete field of vision. You will be asked to look straight ahead as a light spot is presented in different areas of your peripheral vision, helping your eye doctor determine whether your vision has been affected by glaucoma. Peripheral vision loss is a common sign of glaucoma progression.  


This test helps examine the optic nerve for damage. Eye drops are used to dilate the pupils so your doctor can see through your eye to examine the retina and optic nerve. Your optometrist may use special equipment to take pictures and computer measurements of your optic nerve. 

Diagnosing glaucoma is not always easy. That's why Prairie Eye Care utilizes several diagnostic tests to screen for glaucoma at every comprehensive eye exam. Early detection is so important to preserving your eye health and vision. To book your eye exam, contact us today!


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