What Is Glaucoma?
Glaucoma is a condition that damages your eye‘s optic nerve. It gets worse over time. It’s often linked to a buildup of pressure inside your eye. Glaucoma tends to run in families. You usually don’t get it until later in life.
The increased pressure in your eye, called intraocular pressure, can damage your optic nerve, which sends images to your brain. If the damage worsens, glaucoma can cause permanent vision loss or even total blindness within a few years.
Most people with glaucoma have no early symptoms or pain. Visit your eye doctor regularly so they can diagnose and treat glaucoma before you have long-term vision loss.
If you lose vision, it can’t be brought back. But lowering eye pressure can help you keep the sight you have. Most people with glaucoma who follow their treatment plan and have regular eye exams are able to keep their vision.
The fluid inside your eye, called aqueous humor, usually flows out of your eye through a mesh-like channel. If this channel gets blocked, the liquid builds up. Sometimes, experts don’t know what causes this blockage. But it can be inherited, meaning it’s passed from parents to children.
Less-common causes of glaucoma include a blunt or chemical injury to your eye, severe eye infection, blocked blood vessels inside your eye, and inflammatory conditions. It’s rare, but eye surgery to correct another condition can sometimes bring it on. It usually affects both eyes, but it may be worse in one than the other.
Glaucoma Risk Factors
It mostly affects adults over 40, but young adults, children, and even infants can have it. African Americans tend to get it more often, when they’re younger, and with more vision loss.
You’re more likely to get it if you:
- Are of African American, Irish, Russian, Japanese, Hispanic, Inuit, or Scandinavian descent
- Are over 40
- Have a family history of glaucoma
- Have poor vision
- Have diabetes
- Take certain steroid medications such as prednisone
- Have had an injury to your eye or eyes
- Have corneas that are thinner than usual
- Have high blood pressure, heart disease, diabetes, or sickle cell anemia
- Have high eye pressure
- Are nearsighted or farsighted
Types of Glaucoma
There are two main kinds:
Open-angle glaucoma. This is the most common type. Your doctor may also call it wide-angle glaucoma. The drain structure in your eye (called the trabecular meshwork) looks fine, but fluid doesn’t flow out like it should.
Angle-closure glaucoma. This is more common in Asia. You may also hear it called acute or chronic angle-closure or narrow-angle glaucoma. Your eye doesn’t drain like it should because the drain space between your iris and cornea becomes too narrow. This can cause a sudden buildup of pressure in your eye. It’s also linked to farsightedness and cataracts, a clouding of the lens inside your eye.
Less common types of glaucoma include:
Secondary glaucoma. This is when another condition, like cataracts or diabetes, causes added pressure in your eye.
Normal-tension glaucoma. This is when you have blind spots in your vision or your optic nerve is damaged even though your eye pressure is within the average range. Some experts say it’s a form of open-angle glaucoma.
Pigmentary glaucoma. With this form, tiny bits of pigment from your iris, the colored part of your eye, get into the fluid inside your eye and clog the drainage canals.
Most people with open-angle glaucoma don’t have symptoms. If symptoms do develop, it’s usually late in the disease. That’s why glaucoma is often called the “sneak thief of vision.” The main sign is usually a loss of side, or peripheral, vision.
Symptoms of angle-closure glaucoma usually come on faster and are more obvious. Damage can happen quickly. If you have any of these symptoms, get medical care right away:
- Seeing halos around lights
- Vision loss
- Redness in your eye
- Eye that looks hazy (particularly in infants)
- Upset stomach or vomiting
- Eye pain
Glaucoma tests are painless and don’t take long. Your eye doctor will test your vision. They’ll use drops to widen (dilate) your pupils and examine your eyes.
They’ll check your optic nerve for signs of glaucoma. They may take photographs so they can spot changes at your next visit. They’ll do a test called tonometry to check your eye pressure. They may also do a visual field test to see if you’ve lost peripheral vision.