Glaucoma

Glaucoma is a group of eye diseases that damage the optic nerve, potentially leading to vision loss and blindness. Often called the “sneak thief of sight,” this condition can develop slowly without symptoms, making regular eye exams essential for early detection and treatment.

Table of contents

• What is Glaucoma?
• Symptoms of Glaucoma
• Who is at Risk?
• What Causes Glaucoma?
• Types of Glaucoma
• How is Glaucoma Diagnosed?
• Treatment Options
• Living With Glaucoma
• Prevention and Early Detection

What is Glaucoma?

Glaucoma is an eye condition that damages the optic nerve, which is the nerve that connects your eye to your brain and sends visual information between them. This nerve is vital for good vision^[1]. Glaucoma actually refers to many different eye diseases that make pressure build up inside your eyeball, which can damage delicate, critical parts at the back of your eye^[2].

Most forms of glaucoma are progressive, which means they gradually get worse over time. As the disease progresses, it can eventually cause permanent vision loss and blindness. In fact, glaucoma is the second-leading cause of blindness worldwide^[2]. More than four million Americans are currently living with glaucoma^[7].

• Eye
• Optic nerve
• Retina

Symptoms of Glaucoma

The symptoms of glaucoma depend on the type and stage of the condition. In its early stages, glaucoma may not cause any symptoms at all. This is why up to half of the people in the United States with glaucoma may not even know they have it^[2]. The effect is so gradual that you may not notice a change in vision until the condition is in its later stages^[1].

Open-Angle Glaucoma Symptoms

Open-angle glaucoma is the most common type and typically progresses slowly. Early on, there are often no symptoms. Over time, you may develop patchy blind spots in your side vision, which is also called peripheral vision. In later stages, you may have difficulty seeing things in your central vision^[1].

Acute Angle-Closure Glaucoma Symptoms

Some types of glaucoma, particularly angle-closure glaucoma, can cause sudden, severe symptoms that need immediate medical attention. These emergency symptoms include^[1][2]:

• Intense or severe eye pain
• Bad headache
• Red or bloodshot eye
• Nausea or vomiting that happens with eye pain
• Blurred vision
• Seeing rainbow-colored circles or halos around bright lights
• Sudden vision loss of any kind

If you experience any of these sudden symptoms, you should go to your doctor or an emergency room immediately. This is a medical emergency that may require immediate treatment to prevent permanent vision loss^[3].

Who is at Risk?

Anyone can get glaucoma, but some people are at higher risk than others. Understanding your risk factors is important for knowing how often you should get checked^[3].

You’re at higher risk if you^[3][4]:

• Are over age 60, especially if you’re Hispanic or Latino
• Are African American and over age 40
• Have a family history of glaucoma (brother, sister, or parent with glaucoma)
• Are of African, Asian, or Hispanic descent
• Have high eye pressure
• Have had an eye injury
• Have other medical conditions such as diabetes, short-sightedness, or long-sightedness
• Have a thin cornea
• Have a large or thinning optic nerve

Open-angle glaucoma is three to four times more common in African Americans than in non-Hispanic whites and is the leading cause of blindness in African Americans^[7]. Glaucoma prevalence rises rapidly in Hispanics over age 65^[7].

What Causes Glaucoma?

Scientists aren’t entirely sure what causes the most common types of glaucoma, but many people with glaucoma have high eye pressure. The damage to the optic nerve is often related to high pressure inside the eye, though glaucoma can happen even with typical eye pressure^[1][3].

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 called the trabecular meshwork, which is where your iris and cornea come together at an angle^[2].

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^[2].

Sometimes the pressure in the eye is in the normal range, but damage is still caused to the optic nerve. It’s not always known why this happens, but several risk factors can increase your likelihood of developing glaucoma^[5].

Types of Glaucoma

There are many different types of glaucoma, but they mainly fall under a few specific categories^[3][5]:

Primary Open-Angle Glaucoma

This is the most common type of glaucoma in the United States. “Open-angle” means that the drainage angle, where the inside of 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. This type usually develops slowly over many years and often has no symptoms in the early stages^[2][5].

Primary Angle-Closure Glaucoma

This type occurs when the drainage angle becomes blocked or closed. The aqueous humor fluid is supposed to flow from behind your iris, through your pupil, and into the front chamber of your eye. Sometimes this pathway becomes blocked, causing pressure to build up quickly. Angle-closure glaucoma can develop suddenly and cause severe symptoms requiring immediate medical attention^[2].

Secondary Glaucoma

Secondary glaucoma is usually caused by another condition or eye injury^[5].

Congenital Glaucoma

This is a rare type that affects young children and babies^[3][5].

How is Glaucoma Diagnosed?

Eye doctors can check for glaucoma as part of a comprehensive dilated eye exam. The exam is simple and painless. Your doctor will give you some eye drops to dilate (widen) your pupil and then check your eyes for glaucoma and other eye problems^[3].

Several tests may be done during the examination, including^[8]:

• Measuring intraocular pressure (pressure inside the eye), also called tonometry
• Testing for optic nerve damage with a dilated eye exam and imaging tests
• Checking for areas of vision loss with a visual field test to check your side vision
• Measuring corneal thickness with an exam called pachymetry
• Inspecting the drainage angle, also known as gonioscopy

Glaucoma is usually found during a routine eye test, often before it causes any symptoms. If you’re told you have glaucoma, you should be referred to a specialist eye doctor called an ophthalmologist for further tests^[5].

The only way to find out if you have glaucoma is to get a comprehensive dilated eye exam. There’s no way to prevent glaucoma, which is why eye exams are so important—so you and your doctor can find it before it affects your vision^[3].

Treatment Options

The damage caused by glaucoma cannot be reversed. However, treatment and regular checkups can help slow or prevent vision loss, especially if the disease is found in its early stages^[8]. There’s currently no cure for glaucoma, but early treatment can often stop the damage and protect your vision^[3].

Treatment of glaucoma aims to lower intraocular pressure. The only clinically proven treatment for glaucoma is to lower eye pressure^[6]. Treatment options include^[5][8]:

Eye Drops (Medication)

Glaucoma treatment often starts with prescription eye drops. Some may decrease eye pressure by improving how fluid drains from the eye. Others decrease the amount of fluid the eye makes. Depending on how low the eye pressure needs to be, more than one eye drop may be prescribed^[8].

Common types of eye drops include^[8]:

• Prostaglandins: These increase the outflow of fluid in the eye, helping to reduce eye pressure. This class of medicine is usually prescribed for once-a-day use
• Beta blockers: These reduce the production of fluid in the eye, helping to lower eye pressure

Medications must be taken daily to keep eye pressure at a safe level. In most cases, medications can safely control eye pressure for many years^[10].

Laser Treatment

There are different types of laser procedures depending on the type of glaucoma^[10]:

• Selective Laser Trabeculoplasty (SLT): Used for open-angle glaucoma, this procedure uses low levels of laser light to improve drainage of fluid through the natural drainage pathway out of the eye. It is often a first-line treatment and can be repeated as needed^[10][11]
• Laser Peripheral Iridotomy (LPI): This is helpful for people who have angle-closure glaucoma or its precursor stages^[10]

Recent research has shown that selective laser trabeculoplasty may be more effective than eye drops as a first-line treatment, with less disease progression and less need for surgery later^[11].

Surgery

When other treatments do not lower eye pressure to the desired level, your doctor may recommend some form of surgery. This surgery is done in a hospital or surgery center and includes making a cut in the eye. There are several different types of operations to treat glaucoma, including conventional surgery and micro-invasive glaucoma surgery (MIGS)^[10][11].

If you have glaucoma, you’ll need treatment or monitoring for the rest of your life^[1]. You’ll have follow-up appointments to monitor your eyes and check that treatment is working. It’s important not to miss any of these appointments^[5].

Living With Glaucoma

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. With care and careful management, it’s possible to delay—or even prevent—permanent vision loss^[2].

Managing Daily Life

If glaucoma is diagnosed and treated early, it may not change your vision much. But sometimes your sight is affected, and in rare cases you may lose your sight. Your specialist eye doctor will advise you on how it may affect your sight and how to live as independently as you can^[5].

Having glaucoma may mean you need to do things to prevent it from getting worse. For many people, this includes using eye drops daily and attending regular eye clinic appointments^[5]. A good working relationship with your eye doctor is the key to effective glaucoma care^[15].

Try to schedule time for taking medication around daily routines such as waking, mealtimes, and bedtime. In this way, your medications will become a natural part of your day^[15].

Lifestyle Considerations

You can continue with what you were doing before glaucoma was diagnosed. You can make new plans and start new ventures. Using your eyes is not harmful and they do not need to be “rested.” Reading, writing, sewing, computer work, and similar activities all encourage your eyes to focus and can actually help the drain in each eye work more effectively^[18].

Being physically fit and keeping your weight within a healthy range helps to prevent health problems and is important for your overall well-being. Physical activity actually reduces eye pressure directly for at least a few hours^[18]. A well-rounded diet rich in dark, leafy greens and omega-3 fatty acids may have a positive effect on eye health^[16].

However, patients with glaucoma should be mindful of certain activities. You should avoid exercises during which your head is below your heart for extended periods, such as certain yoga poses. You should also avoid sustained straining that increases pressure^[20].

Recent studies have pointed to meditation as a helpful tool to combat high eye pressure in glaucoma patients. Mindfulness is low-risk and has the potential to have many benefits^[16].

Emotional Support

In addition to taking care of your physical health, it’s equally important to pay attention to the emotional and psychological aspects of having this disease. Be sure to share your feelings, especially in the beginning. Confide in your spouse, a relative, a close friend, or a member of the clergy. You may also want to talk with other people who have glaucoma. Sharing ideas and feelings about living with a chronic health condition can be useful and comforting^[15].

Prevention and Early Detection

There’s no way to prevent glaucoma. That’s why eye exams are so important—so you and your doctor can find it before it affects your vision^[3]. Lack of awareness and lack of symptoms prevent people from getting glaucoma diagnosed early^[6].

Everyone should have regular eye tests, at least every two years. If you’re at a higher risk of glaucoma—for example, if you have a brother, sister, or parent with it—you may be advised to have eye tests more often. If you’re at higher risk, you need to get a comprehensive dilated eye exam every one to two years^[3][5].

As many as half of people living with glaucoma may not be aware they have the disease^[7]. Once glaucoma damages your optic nerve, lost vision cannot be restored. However, early detection combined with treatment can slow or stop glaucoma progression^[6].

Getting a comprehensive dilated eye exam is the only way to catch glaucoma early^[6]. Glaucoma does not usually have symptoms and most people do not realize they have it. It develops slowly over many years and is usually picked up during routine eye tests^[5].

If you have a family history of glaucoma, it’s important to tell your relatives. In many cases, glaucoma is an inherited disease that is passed on within families—you are ten times more likely to have glaucoma if you have a direct family member with glaucoma^[18].