Key Takeaways:
- Glaucoma damages the optic nerve and can lead to permanent vision loss if it progresses without treatment.
- Open-angle glaucoma, the most common type, usually develops gradually without noticeable early symptoms.
- Changes in side vision, blurry vision, haloes, eye pain, nausea, and vomiting may occur with certain types or stages of glaucoma.
- Sudden eye pain, redness, blurry vision, headache, nausea, or vomiting may indicate acute angle-closure glaucoma, which is a medical emergency.
- Age, family history, elevated eye pressure, certain health conditions, previous eye injuries, and corticosteroid use can increase your risk.
- Eye pressure testing alone cannot diagnose or rule out glaucoma. A complete assessment examines your optic nerve, visual field, drainage angle, and other factors.
- Glaucoma-related vision loss cannot be reversed, but early diagnosis and treatment can help protect the vision you still have.
Glaucoma is a sneakily progressive eye condition that often presents no symptoms until irreversible damage is done to your vision. However, early detection (through regular eye exams) and glaucoma treatment can prevent vision loss.
While you may not notice early symptoms, 5 possible early signs of glaucoma can include:
- Blurry vision
- Eye pain
- Haloes around lights
- Nausea
- Eye redness
One important point is easy to miss: the most common form, open-angle glaucoma, rarely causes these symptoms in its early stages. Changes often happen so gradually that your brain adapts, and you may not realize part of your side vision has changed. The signs above are more likely when eye pressure rises quickly, as it can with angle-closure glaucoma.
What Is Glaucoma?
Glaucoma is one of the leading causes of blindness in Canada. It’s not a single disease but a group of conditions that damages the optic nerve, usually due to increased pressure in the eye. The function of the optic nerve is to transmit visual information from the eye to the brain. If left untreated, glaucoma can lead to permanent vision loss, so early detection is vital.
Causes of Glaucoma
The exact cause of glaucoma isn’t always clear, but it often results from an imbalance between the production and drainage of fluid in the eye. This fluid, called aqueous humour, flows in and out of the eye, maintaining a healthy pressure. When there is an obstruction or overproduction of this fluid, the pressure inside the eye increases, leading to damage to the optic nerve.
Types of Glaucoma
There are several types of glaucoma, which all fall under primary and secondary glaucomas:
- Open-angle glaucoma. This is the most common type of glaucoma. It develops slowly with a gradual increase in intraocular pressure.
- Angle-closure glaucoma. Can progress gradually or suddenly due to fluid buildup from a blocked drainage system in the eye. Angle-closure glaucoma can lead to a rapid onset of symptoms.
- Normal-tension glaucoma. This is when there is damage to the optic nerve despite normal intraocular pressure. The exact cause of normal-tension glaucoma is not well understood.
- Secondary glaucoma. Glaucoma and optic nerve damage from an injury, surgery, infection, tumour, medical condition, medication, or eye abnormality.
Anyone can develop glaucoma, but some people need closer monitoring. Your risk may be higher if you:
- Have a parent, sibling, or child with glaucoma
- Are over age 60
- Have elevated eye pressure
- Belong to a racial or ethnic group with higher rates of certain forms of glaucoma
- Have diabetes, significant nearsightedness, or certain circulation concerns
- Have experienced an eye injury, eye surgery, inflammation inside the eye, or retinal detachment
- Use corticosteroids, including some eye drops, tablets, injections, inhalers, or nasal sprays
Risk factors are not a diagnosis. They help us decide how often to examine your eyes and which tests may be useful. Family history is especially worth mentioning. If a parent or sibling has glaucoma, let your optometrist know even when your vision seems unchanged.
Do not stop a prescribed steroid because of glaucoma concerns. Instead, tell both the prescriber and your optometrist what you take. Many people can use these medications safely with appropriate eye-pressure monitoring.
Early Warning Signs of Glaucoma
Glaucoma can progress to the later stages and affect your vision without noticeable symptoms. Regular eye exams can detect glaucoma in the early stages to prevent vision loss. Signs of glaucoma usually depend on the type of glaucoma.
Blurry Vision
Glaucoma can cause blurred or hazy vision. Blurry vision may occur intermittently or persistently. If you experience vision that is not as sharp as it used to be, it’s important to schedule an eye exam promptly. Addressing vision changes early can significantly impact the effectiveness of treatment and help preserve your eyesight.
Eye Pain
Glaucoma can cause eye pain, particularly when there is elevated intraocular pressure. You can experience eye pain from various eye conditions, so consult your eye doctor for an accurate diagnosis.
Haloes Around Lights
Seeing haloes or rings around lights, especially in low-light conditions, can indicate early signs of glaucoma. This phenomenon is often associated with increased intraocular pressure. While haloes can sometimes be harmless, persistent haloes may signal an underlying eye issue that requires prompt attention.
Nausea & Vomiting
A sudden onset of symptoms such as nausea and vomiting can occur in angle-closure glaucoma. This type of glaucoma is a medical emergency, as it can quickly lead to vision loss.
Eye Redness
Redness in the eyes from increased eye pressure could be a sign of glaucoma, especially when accompanied by eye pain. This is another symptom that can accompany a variety of eye issues, so visit your eye doctor to determine the cause.
Signs of Glaucoma Progression
As glaucoma progresses, it can lead to loss of peripheral vision. You may notice difficulty seeing objects or movement out of the corner of your eye. Loss of peripheral vision can interfere with daily life, such as driving.
Without treatment, glaucoma can progress to the late stages. Signs of late-stage glaucoma can include loss of central vision, also called tunnel vision, or complete vision loss.
How to Get a Glaucoma Diagnosis
Your optometrist can diagnose glaucoma with a comprehensive eye exam. During the eye exam, they use eye drops to dilate the eyes or widen the pupils to check for signs of glaucoma. They may also do a visual field test to check your peripheral vision.
An eye pressure check is useful, but it can’t confirm or rule out glaucoma on its own. Some people have higher-than-average pressure without optic nerve damage, while others develop glaucoma even when their readings fall within the expected range. That’s why we look at the whole picture.
Glaucoma Assessments
Your assessment may include examining the drainage angle and optic nerve, measuring the thickness of your cornea, and using optical coherence tomography (OCT) to take detailed images of the nerve fibres at the back of the eye. A visual field test checks whether any areas of your side or central vision are less sensitive than they should be.
These tests also create a baseline for future visits. Glaucoma decisions are often based on change over time, so comparing new images and visual field results with earlier ones can reveal progression that would be impossible to identify from a single appointment. Depending on your results, we may recommend monitoring, treatment, or a referral to an ophthalmologist.
Treatment for Glaucoma
While there is no cure for glaucoma, various treatment options can help control the condition, depending on the severity and type of glaucoma, to prevent further vision loss. These may include:
- Prescription eye drops. Helps reduce eye pressure
- Laser treatment. Helps with fluid drainage from the eyes
- Surgery. Helps reduce eye pressure when medication is not enough
Regular eye checkups are fundamental, especially for those at higher risk, such as individuals with a family history of glaucoma, those over 60 years old, people with increased eye pressure, and people with certain medical conditions, like diabetes.
When to Seek Medical Attention
Glaucoma doesn’t always create a clear moment when you know you need care. The safest response depends on how suddenly the change appeared, how severe it is, and whether several symptoms are happening together.
Vision Changes
Seek emergency eye care if severe eye pain or a sudden drop in vision develops with a red eye, headache, haloes, nausea, or vomiting. That combination can happen during an acute angle-closure attack, and the eye pressure may need to be lowered quickly to protect your sight. Contact an emergency eye care provider or go to the nearest emergency department. If your vision is affected, ask someone else to drive you.
Book a prompt eye test if you notice a new blind spot, a meaningful change in your side vision, recurring discomfort, or a vision change that persists or affects one eye more than the other. These problems may have another cause, but they should be assessed by an eye doctor.
Other Life Changes
You should also arrange an exam if a close relative has recently been diagnosed with glaucoma, you have started long-term corticosteroid treatment, or you are overdue for monitoring after previously being told your eye pressure or optic nerve looked unusual.
Because glaucoma is often found before symptoms appear, preventive care still counts as medical attention. Following the exam schedule your optometrist recommends gives them the best chance to identify a concerning trend before it begins affecting your everyday life.
Preserve Your Vision with Eye Exams
Glaucoma is a serious eye condition that can result in permanent vision loss if not detected early. Detection of the early signs of glaucoma means you can receive a proper diagnosis and prevent further eye damage and vision loss. Take a proactive approach and book an appointment with St. Clair Eye Clinic to monitor your eye health and vision.
Frequently Asked Glaucoma Questions
What are the first signs of glaucoma?
The most common type, open-angle glaucoma, usually has no noticeable early symptoms. As it progresses, you may develop blind spots or lose part of your side vision. Sudden eye pain, redness, blurry vision, haloes, headache, nausea, or vomiting are more closely associated with acute angle-closure glaucoma and require emergency care.
Can you have glaucoma with normal eye pressure?
Yes. Normal-tension glaucoma causes optic nerve damage even when eye-pressure readings remain within the expected range. Conversely, some people have elevated pressure without developing glaucoma. Your optometrist must consider your optic nerve, visual field, corneal thickness, drainage angle, and changes over time rather than relying on one pressure measurement.
Who is most at risk of developing glaucoma?
Your risk may be higher if you are over 60, have a close relative with glaucoma, have elevated eye pressure, or live with diabetes or significant nearsightedness. Previous eye injuries, eye surgery, inflammation, retinal detachment, and long-term corticosteroid use can also increase risk. Your optometrist can recommend an appropriate exam schedule.
How does an optometrist test for glaucoma?
Glaucoma testing may include measuring eye pressure, examining the optic nerve and drainage angle, testing side vision, and measuring corneal thickness. Optical coherence tomography, or OCT, can produce detailed images of the optic nerve fibres. Results are often compared over time because subtle progression may be more meaningful than a single reading.
When are glaucoma symptoms an emergency?
Seek immediate medical attention for severe eye pain or a sudden vision change accompanied by redness, headache, haloes, nausea, or vomiting. These symptoms may indicate acute angle-closure glaucoma, which can damage vision quickly. Contact an emergency eye care provider or visit the nearest emergency department, and do not drive if your vision is affected.
Where can I get tested for glaucoma in Midtown Toronto?
St. Clair Eye Clinic provides comprehensive eye examinations and glaucoma care in Midtown Toronto. We can assess your eye pressure, optic nerves, visual field, personal risk factors, and previous test results. If you have a family history of glaucoma or have been told your eye pressure is elevated, contact us to arrange an examination.