Glaucoma

What is glaucoma?

Glaucoma is an umbrella term for eye diseases that make pressure build up inside your eyeball, which can damage delicate, critical parts at the back of your eye. Most of these diseases are progressive, which means they gradually get worse. As they do, they can eventually cause permanent vision loss and blindness. In fact, glaucoma is the second-leading cause of blindness worldwide.

Learning that you have glaucoma or that you’re at risk for it can be hard to process. For most people, vision is the sense they rely on most in their daily routine. It can feel scary to imagine trying to adapt to and live your life after you have severe vision loss. But most forms of glaucoma are treatable, especially when diagnosed early. And with care and careful management, it’s possible to delay — or even prevent — permanent vision loss.

What are the symptoms of glaucoma?

In its early stages, glaucoma may not cause any symptoms. That’s why up to half of the people in the United States with glaucoma may not know they have it. And symptoms may not appear until this condition causes irreversible damage.

Some of the more common glaucoma symptoms include:

• Eye pain or pressure
• Headaches
• Red or bloodshot eyes
• Double vision (diplopia)
• Blurred vision
• Gradually developing low vision
• Gradually developing blind spots (scotomas) or visual field defects like tunnel vision

Some types of glaucoma, particularly angle closure glaucoma, can cause sudden, severe symptoms that need immediate medical attention to prevent permanent vision loss. Emergency glaucoma symptoms include:

• Blood gathering in front of your iris (hyphema)
• Bulging or enlarged eyeballs (buphthalmos)
• Nausea and vomiting that happen with eye pain/pressure
• Rainbow-colored halos around lights
• Sudden appearance or increase in floaters (myodesopsias)
• Sudden vision loss of any kind
• Suddenly seeing flashing lights (photopsias) in your vision

What causes glaucoma?

Glaucoma is caused by damage to your optic nerve. It can occur without any cause, but many factors can affect the condition. The most important of these risk factors is intraocular eye pressure. Your eyes produce a fluid called aqueous humor that nourishes them. This liquid flows through your pupil to the front of your eye. In a healthy eye, the fluid drains through mesh-like canals (trabecular meshwork), which is where your iris and cornea come together at an angle.

With glaucoma, the resistance increases in your drainage canals. The fluid has nowhere to go, so it builds up in your eye. This excess fluid puts pressure on your eye. Eventually, this elevated eye pressure can damage your optic nerve and lead to glaucoma.

What makes the fluid build up can vary, depending on the specific overall type of glaucoma you have.

Types of glaucoma

There are many different types of glaucoma, but they mainly fall under a few specific categories:

• Primary open-angle glaucoma. “Open-angle” means that the drainage angle, where the inside of the sclera (the white of your eye) and the outer edge of your iris meet, is open wide. Aqueous humor flows into the drainage angle so it can drain out of the anterior chamber. This is the most common type of glaucoma.
• Primary angle-closure glaucoma. Aqueous humor fluid is supposed to flow from the posterior chamber behind your iris, through your pupil, and into the anterior chamber. But sometimes, the lens of your eye presses too far forward, blocking fluid from flowing through the pupil opening. The extra fluid in the posterior chamber forces the iris forward, narrowing or closing off the drainage angle.
• Secondary glaucoma. This is when another condition or event increases eye pressure, which leads to glaucoma. Conditions that can cause it include eye injuries, pigmentary dispersion syndrome, uveitis, certain medications (especially corticosteroids and cycloplegics), eye procedures and more.
• Congenital glaucoma. This means you have glaucoma because of changes or differences that happened during fetal development. These include aniridia, Axenfeld-Rieger syndrome, Marfan syndrome, congenital rubella syndrome and neurofibromatosis type 1.

What are the risk factors for glaucoma?

Several risk factors can contribute to glaucoma. They include:

• Age. Most types of glaucoma affect people age 40 and older (congenital types are the biggest exception to this). Experts estimate that 10% of people age 75 and older have glaucoma.
• Race. Black people have a much higher risk of developing primary open-angle glaucoma, especially people of Afro-Caribbean descent. People of African descent are 15 times more likely to have blindness from open-angle glaucoma. People of Asian and Inuit descent have a higher risk of angle-closure glaucoma.
• Sex. People assigned female at birth (AFAB) have a higher risk of angle-closure glaucoma. Experts suspect this is mainly because of sex-linked differences in eye anatomy.
• Refractive errors. People with nearsightedness (myopia) have a higher risk of open-angle glaucoma. People with farsightedness (hyperopia) have a higher risk of angle-closure glaucoma.
• Family history. There’s evidence that a family history of glaucoma, especially a first-degree biological relative (a parent, child or sibling), means you also have a higher risk of developing it. And several conditions that cause secondary glaucoma are genetic, too.
• Chronic conditions. Research links some conditions, like high blood pressure (hypertension) and diabetes, to much higher odds of developing glaucoma.

What are the complications of glaucoma?

Without care to manage it and lower the pressure inside your eye, glaucoma damages your retina and optic nerve to the point where they stop working. That causes glaucoma’s main complication: vision loss and, eventually, total blindness.

The end result is what experts call “absolute glaucoma.” That means you’re totally blind in the affected eye. The affected eye feels hard — and maybe even painful — when you touch it.

How is glaucoma diagnosed?

An eye care specialist can diagnose glaucoma using an eye exam, including several tests that are part of routine eye exams. In fact, eye exams can detect glaucoma long before you have eye damage and the symptoms that follow. Many of these tests involve pupil dilation (mydriasis), so your provider can get a better look inside your eye.

Some of the most helpful glaucoma tests include:

• Visual acuity testing
• Visual field testing
• Depth perception testing
• Tonometry
• Pachymetry
• Slit lamp exam
• Gonioscopy

If your eye care specialist has a reason to suspect damage to your retina and/or optic nerve, they may also use additional types of eye imaging. These include:

• Optical coherence tomography
• Fluorescein angiography
• Ultrasound
• Less commonly, computed tomography (CT) or magnetic resonance imaging (MRI)

How is glaucoma treated?

The top priority for treating glaucoma is to keep it from getting worse by lowering the pressure inside your eye (intraocular pressure).

Some of the most likely treatments for this include:

• Medications. This mainly involves medications that lower pressure inside your eye. They can prevent glaucoma from developing if you have higher-than-normal intraocular pressure (ocular hypertension) or keep it from worsening enough to cause damage and symptoms.
• Glaucoma surgeries. These mainly focus on improving the drainage of aqueous humor fluid to lower pressure inside your eye. Surgery options include trabeculectomy, tube shunts, laser therapy and minimally invasive glaucoma surgeries (MIGS).

Other treatments are possible, depending on what type of glaucoma you have, how it’s affecting your eye and other factors. Your eye care specialist can tell you more about your treatment options and help you choose one that fits your needs best.

Can glaucoma be prevented?

Glaucoma isn’t preventable, but early detection and treatment can manage pressure inside your eye and help prevent or delay vision loss. There are a few main ways that can happen:

• Regular eye exams. Pressure increases in your eyes are often detectable before they can cause glaucoma and its symptoms. Early detection lets you and your eye specialist try to prevent glaucoma from worsening or, at least, slow down its progress.
• Managing ocular hypertension. If you have higher-than-normal pressure in your eyes, your eye care specialist can offer treatment options. Following their guidance can be crucial and help you avoid — or at least delay — vision loss.
• Knowing and managing your risk factors. Some of the conditions that you can try to manage or prevent include high blood pressure and diabetes. Using protective items like safety glasses and goggles can help prevent eye injuries.

What’s the outlook for glaucoma?

Without treatment, glaucoma inevitably causes permanent vision loss and blindness. With treatment, it’s possible to slow the progress of the disease or stop it entirely. But because the range of possibilities can vary so widely, your eye specialist is the best person to talk to about this. They can tell you the likely outlook for your specific case and what you can do to help tilt the scales in your favor.

What can I do to help myself if I have glaucoma?

If you have glaucoma, the best thing you can do is follow your eye care specialist’s guidance on treating and managing this condition. They may also recommend making certain changes to your life, habits or routine. These can include:

• Not ignoring new symptoms or vision changes
• Reaching and maintaining a weight that’s healthy for you
• Staying physically active (but be sure to ask about which activities to avoid, as some can increase eye pressure)
• Seeing your provider as recommended

You should also see your provider if you notice new symptoms, if treatments aren’t as effective or if you have treatment side effects that are disrupting your life.

When should I seek medical care?

Angle-closure glaucoma usually develops quickly, so it needs immediate medical attention to prevent permanent damage and vision loss. The symptoms to watch for are the sudden onset or worsening of:

• Severe eye pain or pressure
• Headaches
• Double vision (diplopia) or blurred vision
• Nausea and vomiting that happen with eye pain/pressure
• Rainbow-colored halos around lights
• Vision loss of any kind
• Flashing lights in your vision
• Appearance or increase in visible floaters

What questions should I ask my eye care specialist?

Some questions you may want to ask your eye care specialist include:

• What type of glaucoma do I have?
• What’s causing my glaucoma?
• What are the treatment options available to me, and which do you recommend?
• What are the possible side effects or complications of the treatment(s)?
• What symptoms or changes mean I should call your office or get medical care?