Glaucoma Overview

Glaucoma is a group of eye diseases that cause damage to an essential nerve in your eye. If left untreated, it can lead to blindness. Glaucoma often doesn't have early symptoms, and can only be diagnosed through an eye exam, which is why regular trips to an ophthalmologist are so important. If you do have glaucoma, a combination of treatments like eye drops, oral medications, and surgery can help to slow down permanent vision loss.

What Is It?

In the back of each of your eyes lies an optic nerve — a bundle of tiny nerves that sends visual data to your brain, where it can then be interpreted. If your optic nerve becomes damaged in any way, blind spots will start to appear in your field of vision.

Doctors don't yet understand why, but optic nerve damage is often caused by high eye pressure. This happens when fluid can't naturally drain from the front of your eye.

Between your cornea (the clear part of your eye) and your iris (the colored part of your eye) lies a space called the anterior chamber. Excess fluid flows through here, then out of a tiny, spongy opening. If any part of this system stops working correctly, pressure in your eye builds up.

You can't feel this happening. Glaucoma often has no early symptoms, and damage to the optic nerve usually happens so slowly that many people don't even notice that their vision is slowly changing.

Types

The different kinds of glaucoma include:

Open-angle glaucoma: This is the most common type of glaucoma. If you have this type, your eye's drainage canals become clogged, increasing your eye pressure and gradually causing harm to your optic nerve.

Closed-angle glaucoma: Also known as "acute glaucoma," this type isn't as common. Blocked drainage canals in your eye prevent your iris from opening as wide as it should. As a result, your eye pressure can rise very rapidly.

Normal-tension glaucoma: If you have this kind of glaucoma, your optic nerve becomes dysfunctional even though your eye pressure is still within normal range.

Pigmentary glaucoma: Tiny pigment granules from your iris can become loose and start to build up in your eye's drainage canals. Eye pressure may only spike during exercise, then return to normal levels, but it's still enough to damage your optic nerve.

Symptoms

What you notice will depend on the type of glaucoma you have and how severe it is. For instance:

Open-angle glaucoma typically has no early symptoms. Once it progresses, you could notice blind spots in your side or central vision, often in both eyes. Over time, you may start to have tunnel vision.

If you have closed-angle glaucoma, you could experience:

• Headaches.
• Eye pain.
• Eye redness.
• Nausea.
• Vomiting.
• Seeing rainbows around lights at night.
• Extremely blurred vision.

Symptoms for normal-tension glaucoma can include:

• Blood pressure changes.
• Blurred vision.
• Migraines.
• Itchy or stinging eyes.

Most people with pigmentary glaucoma don't have any symptoms, although you could have trouble seeing things on either side, occasionally have blurry vision, or see halos around lights.

Causes

You're more likely to develop glaucoma if you are:

• Prone to high eye pressure.
• Black, Asian, or Hispanic.
• Over the age of 60.
• Related to others who have glaucoma.
• Either very near-sighted or very far-sighted.

Other risk factors include:

• A serious eye injury.
• Some types of eye surgery.
• A thin cornea.
• Extended use of corticosteroid medications, including eye drops.

Complications from some specific health problems can also lead to glaucoma. Among them are:

• Cataracts.
• Eye tumors.
• Diabetes.
• High blood pressure.
• Heart disease.
• Sickle cell anemia.

Diagnosis

Vision loss from glaucoma is permanent, which is why it's so important to spot glaucoma early. That can only be done through a complete eye exam, which is more thorough than getting fitted for glasses or contact lenses. During this exam, an ophthalmologist (eye doctor) will check the health of your eye by:

Taking your eye pressure. After your eyes are numbed with special eyedrops, a tiny instrument will touch their surfaces to gauge the pressure.

Checking your angle. A crucial part of this exam is examining where your cornea meets your iris, since this "angle" is where your eye's drainage system is located.

Examining your optic nerve. Once your pupils are dilated (opened) with special drops, your eye doctor has a clear view of the very back of your eye.

Testing your side vision. This helps your eye doctor understand if you've lost any peripheral eyesight, and if so, how much.

Measuring the thickness of your cornea. Its thickness can impact your eye pressure.

Treatment

There's no way to reverse any eye damage that's already happened due to glaucoma, so your doctor will focus treatment on lowering your eye pressure and preserving the vision you still have. Based on the type and severity of your glaucoma, your treatment could consist of a few different things.

Eye drops: Medications that go directly into your eyes can improve how well fluid drains out, or lessen the amount of fluid that your eyes make. Some people need more than one kind of eye drop. Since glaucoma is a chronic condition, you'll need to be prepared to use eye drops for the rest of your life.

Oral medicines: Your doctor could also prescribe a medication that you take by mouth to reduce your eye pressure.

Laser treatment: A laser may be used to open any blocked areas in your eye and help fluid drain more easily. In some cases, the results from laser treatment can last up to five years.

Surgery: Several different surgical procedures can reduce and stabilize your eye pressure. Surgery works much more quickly than drops, and although it's more invasive, it can be a good choice for people with advanced glaucoma.

Prevention

To do your best to protect your vision, try to:

Eat your (green, leafy) veggies. Some studies have shown that this particular type of veggie — think kale and collard greens — may lower your risk of some types of glaucoma.

Watch your caffeine intake. Caffeine can raise your eye pressure for as much as 90 minutes. That doesn't necessarily mean you have to give it up altogether, but if you drink a lot of coffee, consider cutting back.

Stay active. Regular exercise helps reduce your eye pressure.

Protect your eyes. Eye injuries increase your risk of glaucoma. Wear protective eyewear when you're playing a sport or doing another type of activity where your eyes could be hurt.

Schedule regular eye exams. Although having your eyes dilated can be inconvenient, it's important for an eye doctor to get a full look at your entire eye. Schedule an exam every five to ten years if you're under 40 and every two to four years if you're between the ages of 40 and 54. If you're older than 55 years old or at risk of glaucoma, talk to your eye doctor. You may need to be checked as frequently as once each year.

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