The Pressure is On: A Clear Look at Glaucoma

If you’ve recently been diagnosed with glaucoma—or you’re seeking to better understand it for yourself or someone you care about—you’re not alone, and it’s completely normal to have questions. Glaucoma can sound like a serious and overwhelming condition, but with the right information, it becomes much easier to understand and manage. Let’s take a closer look together.

Many people think glaucoma is one single condition, but it’s actually a group of eye diseases that all have one thing in common: they cause damage to the nerve at the back of your eye, which connects your eye to your brain. This nerve is called the optic nerve, and it plays a big role in helping you see.

To understand how glaucoma happens, we need to take a quick look inside the eye [Figure 1]. Think of the eye as having two main sections:

• The front part, called the anterior chamber – this includes your cornea (the clear front window of your eye), your iris (the colored part), and your pupil.
• The back part, or posterior chamber – this includes things like the lens, the muscles, and other deeper structures.

Figure 1 – Diagram of the eye. Created by Dr Mojibola Orefuja

Now, your eye is constantly producing a clear fluid (not tears) that flows through the front part of the eye. This fluid keeps the eye healthy and nourished, but it also needs to drain out through tiny channels in the corners of your eye. In glaucoma, this drainage system doesn’t always work properly. When the fluid can’t drain out, pressure builds up inside the eye.

This pressure is called intraocular pressure (IOP). Normally, it stays between 10 and 21 mmHg (a unit of pressure measurement). But when the pressure gets too high, it can slowly damage the optic nerve. That’s what leads to glaucoma.

Types of Glaucoma

Not all glaucoma is the same. There are a few different types, and each works a little differently:

1. Ocular Hypertension – This just means your eye pressure is higher than normal, but your optic nerve is still healthy and there’s no vision loss. So technically, it’s not glaucoma yet—but it can lead to it over time if not monitored.

2. Primary Open-Angle Glaucoma (POAG) – This is the most common type. The drainage system in your eye doesn’t work as fast as it should, so fluid builds up slowly over time—like a slow-draining sink. That pressure gradually damages the optic nerve. It usually happens without pain and without you noticing any symptoms at first, which is why it’s often called the “silent thief of sight.”

3. Acute Angle-Closure Glaucoma (AACG) – This is a medical emergency. It happens suddenly when the drainage angle in your eye becomes completely blocked. The pressure shoots up fast and can cause severe eye pain, blurry vision, red eye, and even nausea. If you experience these symptoms, get medical help right away.

4. Chronic Angle-Closure Glaucoma (CACG) – This one’s a slower version of AACG. The angle narrows gradually over time, leading to a slow rise in pressure. Often, people don’t notice symptoms until significant damage has already occurred.

Who’s at Risk?

Glaucoma can affect anyone, but some people are more likely to develop it. Here are a few risk factors:

• Age: Your risk goes up as you get older.
• Family History: If your parents or siblings have glaucoma, you’re more likely to get it too.
• Ethnicity: Glaucoma is more common in people of African or Caribbean descent.
• Steroid Use: Long-term use of steroid medications (like for asthma or arthritis) may increase your risk.
• Short-sightedness (Myopia): If you’re very nearsighted, your eye shape may make fluid buildup more likely.
• Diabetes: This condition can increase your risk of glaucoma.
• High Blood Pressure: This may also play a role in damaging the optic nerve.

Signs and Symptoms

Open-angle glaucoma, which is the most common type, usually doesn’t cause symptoms early on. That’s why regular eye checks are so important. Over time, people may notice blind spots in their peripheral vision—the sides of your vision when you’re looking straight ahead.

Because this type of glaucoma creeps up slowly, it’s important to keep an eye on your intraocular pressure (IOP). Your eye doctor will check this during routine exams.

Acute angle-closure glaucoma, on the other hand, has very noticeable symptoms that come on fast:

• Sudden eye pain or a headache around your eye
• Red eye
• Blurred or lost vision
• Seeing halos or rainbows around lights
• Nausea and vomiting

If this happens to you, it’s an emergency—go straight to the hospital or an eye clinic.

How Is It Diagnosed?

Most of the time, glaucoma is picked up during a routine eye test with your optometrist (your regular eye doctor). They’ll check your eye pressure and take a close look at your optic nerve.

If anything looks unusual, they’ll refer you to a specialist eye doctor—an ophthalmologist—who will take over your care. They might do a few more tests to confirm what’s going on and figure out the best treatment for you.

That’s why it’s so important to have regular eye checks—ideally every two years, or more often if you’re at higher risk.

Treatment: What Can Be Done?

Unfortunately, any vision that’s lost due to glaucoma usually can’t be reversed. But the good news is, with early detection and the right treatment, we can slow down or stop it from getting worse.

Treatment depends on how severe your glaucoma is, but common options include:

• Eye drops – These are often the first step. They work to lower the pressure in your eye.
• Laser treatment – A quick, painless procedure that helps improve the drainage system in your eye.
• Surgery – In some cases, a small operation is done to create a new drainage channel.

Your eye specialist will work with you to decide the best treatment plan. The most important thing is to stick to your treatment, attend your check-ups, and let your doctor know if anything changes with your vision.

Glaucoma might sound overwhelming at first, but knowing what it is—and catching it early—makes a big difference. Many people live full, active lives with glaucoma by simply staying on top of their eye care.

Here’s a quick summary:

• Glaucoma is a group of eye diseases that damage the optic nerve, often due to high pressure inside the eye.
• It often has no early symptoms, especially the most common type.
• Regular eye tests are key to catching it early.
• Treatment can slow or stop further vision loss—but vision that’s already gone can’t be restored.
• With good management, you can protect your sight and your quality of life.

Thanks for taking the time to learn about glaucoma! If you ever have concerns or just want to talk about your eye health, don’t hesitate to reach out to your optometrist or doctor. Your eyes are too important to ignore, and you’re doing the right thing by learning more.

Stay well—and take care of those eyes!

Reference

1. National Institute for Health and Care Excellence (NICE). Glaucoma. [Internet]. Clinical Knowledge Summaries; 2023 [cited 2025 Apr 8]. Available from: https://cks.nice.org.uk/topics/glaucoma/
2. National Health Service (NHS). Glaucoma. [Internet]. NHS; 2023 [cited 2025 Apr 8]. Available from: https://www.nhs.uk/conditions/glaucoma/
3. American Academy of Ophthalmology. What Is Glaucoma? [Internet]. AAO; 2023 [cited 2025 Apr 8]. Available from: https://www.aao.org/eye-health/diseases/what-is-glaucoma
4. Glaucoma Research Foundation. Understanding Glaucoma. [Internet]. Glaucoma.org; 2023 [cited 2025 Apr 8]. Available from: https://glaucoma.org/understanding-glaucoma
5. American Academy of Ophthalmology. What Is Ocular Hypertension? [Internet]. AAO; 2023 [cited 2025 Apr 8]. Available from: https://www.aao.org/eye-health/diseases/what-is-ocular-hypertension
6. BMJ Best Practice. Chronic open-angle glaucoma. [Internet]. BMJ; 2023 [cited 2025 Apr 8]. Available from: https://bestpractice.bmj.com/topics/en-gb/372
7. BMJ Best Practice. Acute angle-closure glaucoma. [Internet]. BMJ; 2023 [cited 2025 Apr 8]. Available from: https://bestpractice.bmj.com/topics/en-gb/373