This information was created to help patients and their families find general details about glaucoma. The best source for specific questions is an eye care professional who has examined the patient’s eyes and knows their medical history.
Glaucoma Defined
What is Glaucoma?
Glaucoma refers to a group of diseases that harm the optic nerve, potentially leading to vision loss and blindness. However, detecting it early and getting proper treatment can help protect your eyesight and prevent serious damage.
The Optic Nerve
The optic nerve is made up of over a million nerve fibers. It links the retina to the brain. (See diagram above.) The retina is a light-sensitive layer at the back of the eye. A healthy optic nerve is essential for clear vision.
How does the optic nerve get damaged by open-angle glaucoma?
Several major studies have found that eye pressure is a key risk factor for optic nerve damage. At the front of the eye, there is a space called the anterior chamber. A clear fluid constantly moves in and out of this chamber, providing nutrients to nearby tissues. The fluid exits the chamber at the open angle where the iris and cornea meet. (See diagram below.) Once the fluid reaches this angle, it drains through a spongy mesh-like system before leaving the eye.
In open-angle glaucoma, the drainage angle remains open, but the fluid does not pass through the meshwork efficiently. When the fluid drains too slowly, it builds up, raising eye pressure to a level that can harm the optic nerve. If the optic nerve becomes damaged due to high pressure, open-angle glaucoma can develop, leading to vision loss. This is why keeping eye pressure under control is crucial.
Blood pressure is another factor that can contribute to optic nerve damage. It is important to work with your doctor to maintain a healthy blood pressure level for your body.
Can I develop glaucoma if my eye pressure is high?
Not always. Having increased eye pressure does not necessarily mean you will develop glaucoma. Some people can handle higher eye pressure without problems, while others may be more sensitive to it. What is considered high for one person may be normal for another.
Glaucoma develops based on how much pressure your optic nerve can handle before damage occurs. This threshold varies from person to person. That is why a comprehensive eye exam with pupil dilation is essential. Your eye care provider can determine what eye pressure level is safe for you.
Can I develop glaucoma without having high eye pressure?
Yes, it is possible to have glaucoma even if your eye pressure is normal. This type is called normal-tension or low-tension glaucoma. It is a form of open-angle glaucoma.
Who is at risk for open-angle glaucoma?
Glaucoma can affect anyone, but some people are at a higher risk, including:
African Americans over the age of 40
Everyone over 60, especially Mexican-Americans
People with a family history of glaucoma
A thorough eye exam with dilation can help identify additional risk factors, such as high eye pressure, a thin cornea, or an unusually shaped optic nerve. For people with certain high-risk factors, using prescribed eye drops may lower the chances of developing glaucoma by nearly half.
Glaucoma Symptoms
At first, open-angle glaucoma does not cause any symptoms. There is no pain, and vision remains unchanged. It can develop in one or both eyes without noticeable signs.
Without treatment, glaucoma gradually leads to a loss of peripheral (side) vision. As the disease progresses, people may not notice objects at the edges of their sight, as if they are looking through a tunnel. Over time, central (straight-ahead) vision can also fade, eventually leading to complete vision loss.
How is glaucoma detected?
A comprehensive eye exam with dilation is used to detect glaucoma. This exam includes:
Visual acuity test. This measures how clearly you can see at different distances using an eye chart.
Visual field test. This checks your peripheral (side) vision to determine if any vision loss has occurred, which can be a sign of glaucoma.
Dilated eye exam. Eye drops are used to widen the pupils, allowing your eye doctor to examine the retina and optic nerve for damage. Your near vision may be blurry for a few hours afterward.
Tonometry. This test measures the pressure inside the eye with a device called a tonometer. Numbing drops may be used to make the test more comfortable.
Pachymetry. This measures the thickness of the cornea using a device that sends ultrasonic waves. Numbing drops are applied before the test.
Can glaucoma be cured?
No, there is no cure for glaucoma. Any vision lost due to the disease cannot be regained.
Glaucoma Treatments
Early treatment for open-angle glaucoma can help slow the progression of the disease. That’s why getting diagnosed as soon as possible is so important.
Treatment options for glaucoma include medication, laser trabeculoplasty, conventional surgery, or a combination of these methods. While these treatments can help preserve your remaining vision, they cannot restore any sight that has already been lost.
Medicines
Eye drops or pills are the most common early treatments for glaucoma. When taken as prescribed, these medications lower eye pressure. Some work by reducing the amount of fluid the eye produces, while others help the fluid drain more effectively.
Before starting glaucoma medication, let your eye doctor know about any other medicines or supplements you take. Some eye drops may interfere with other treatments.
It’s important to use glaucoma medication exactly as directed. Most people tolerate them well, but some may experience side effects like headaches or irritation. Some eye drops may cause temporary stinging, burning, or redness.
There are many types of glaucoma medications available. If you have side effects or difficulty with one, talk to your eye doctor about adjusting your dosage or trying a different medication.
Since glaucoma usually has no symptoms, some people forget to take their medication or may be tempted to stop using it. However, it’s crucial to keep taking it as long as it helps control eye pressure. Sticking to the treatment plan is essential for protecting your vision.
Your eye doctor should show you how to properly apply eye drops. Following the correct technique can help ensure they work effectively.
Laser Trabeculoplasty
Laser trabeculoplasty is a procedure that helps improve fluid drainage in the eye. Your doctor may suggest this option at any stage of treatment. In most cases, medication is still needed after the procedure.
This treatment is done in an eye clinic or doctor’s office. Before the procedure, numbing drops are applied to your eye. You will sit in front of a laser machine while your doctor holds a special lens to your eye. A high-intensity laser beam is directed through the lens to target the eye’s drainage system. You may see flashes of green or red light. The laser makes small burns that stretch the drainage openings, allowing fluid to drain more efficiently.
As with any procedure, laser surgery can have side effects, such as inflammation. Your doctor may prescribe eye drops to reduce soreness or swelling. Several follow-up appointments will be needed to monitor eye pressure and healing.
If both eyes need treatment, only one will be treated at a time. The second eye is usually treated a few days or weeks later.
Studies show that laser surgery can lower eye pressure for many patients, but the effects may wear off over time, and additional treatments may be necessary.
Conventional Surgery
Conventional surgery creates a new drainage channel for eye fluid. This procedure is usually recommended if medications and laser treatments have not successfully controlled eye pressure.
Known as trabeculectomy, the surgery takes place in an operating room. Before the procedure, you will be given medication to help you relax. Your doctor will use small injections around your eye to numb it. A tiny section of tissue is removed to form a new opening that allows fluid to drain. This drainage process forms a small blister-like bump, called a filtration bleb, under the eye’s surface.
After surgery, you will need to use prescription eye drops for several weeks to prevent infection and reduce inflammation. These drops may be different from the ones you used before surgery.
Like laser surgery, conventional surgery is performed on one eye at a time. The second eye is usually treated four to six weeks later.
Conventional surgery is successful in lowering eye pressure in about 60 to 80 percent of patients. However, the new drainage opening may narrow over time, and a second procedure might be needed. This surgery tends to be most effective in patients who have not had previous eye surgeries, such as cataract removal.
Some people may notice that their vision is not as sharp after surgery. Possible side effects include cataracts, corneal issues, inflammation, infection, or very low eye pressure. If you experience any problems after surgery, inform your doctor so they can recommend the best course of treatment.
What are some other forms of glaucoma, and how are they treated?
The most common type of glaucoma is open-angle glaucoma, but some people develop other forms of the disease.
Low-Tension or Normal-Tension Glaucoma
In this type of glaucoma, the optic nerve becomes damaged, and peripheral vision narrows, even though eye pressure remains in the normal range. In some cases, lowering eye pressure by at least 30 percent with medication can help slow the disease. However, for some people, glaucoma may continue to worsen despite having low eye pressure.
A complete medical history is important to check for other risk factors, like low blood pressure, which can contribute to low-tension glaucoma. If no additional risks are found, treatment options for this type of glaucoma are the same as those for open-angle glaucoma.
Angle-Closure Glaucoma
With angle-closure glaucoma, the fluid in the front of the eye cannot drain properly because part of the iris blocks the drainage angle. This can cause a sudden rise in eye pressure. Symptoms may include severe eye pain, nausea, eye redness, and blurred vision. If you experience these symptoms, seek medical care immediately. This is an emergency. If your doctor is not available, go to the nearest hospital or clinic. Without treatment, blindness can occur.
In most cases, laser surgery and medication can quickly remove the blockage, reduce eye pressure, and protect vision.
Congenital Glaucoma
Congenital glaucoma occurs when a baby is born with an abnormal drainage angle that slows fluid movement in the eye. Children with this condition often have noticeable symptoms, such as cloudy eyes, extreme sensitivity to light, and excessive tearing.
Surgery is usually the preferred treatment, as medication is often ineffective, difficult to administer in infants, and may cause serious side effects. Surgery for congenital glaucoma is both safe and effective, and when performed early, it gives children a high chance of maintaining good vision.
Secondary Glaucomas
Some types of glaucoma develop as a result of other health problems. One severe form, called neovascular glaucoma, can occur due to uncontrolled diabetes or high blood pressure. Other forms of glaucoma may be linked to cataracts, certain eye tumors, or an inflammatory condition known as uveitis. Some cases arise after serious eye injuries or previous eye surgeries. The use of steroid medications for eye inflammation and other diseases can also trigger glaucoma in some individuals.
There are also two specific eye conditions that can lead to secondary glaucoma:
Pigmentary glaucoma occurs when pigment from the iris breaks off and clogs the drainage system, slowing fluid outflow.
Pseudoexfoliation glaucoma happens when extra material builds up inside the eye and blocks the drainage system, leading to increased pressure.
Treatment for secondary glaucoma depends on the cause and may include medication, laser surgery, or traditional glaucoma surgery.
What Research is Being Done?
Researchers at NEI are working to improve ways to detect, treat, and prevent vision loss caused by glaucoma. Scientists have identified genes that may help explain how glaucoma affects the eye.
NEI is also conducting studies to learn more about who is most at risk for glaucoma when treatment should begin for people with high eye pressure, and which treatment options are most effective.
What You Can Do
If you are receiving treatment for glaucoma, it is important to take your medication every day as prescribed. Make sure to visit your eye doctor regularly for check-ups.
You can also help protect the vision of family and friends who may be at higher risk for glaucoma. This includes African Americans over 40, everyone over 60 (especially Mexican Americans), and those with a family history of the disease. Encourage them to schedule a comprehensive dilated eye exam at least once every two years. Detecting glaucoma early and lowering eye pressure can help slow the disease and preserve vision.
Medicare provides coverage for an annual dilated eye exam for some people at high risk for glaucoma. This includes individuals with diabetes, those with a family history of the disease, and African Americans aged 50 and older.
What Should I Ask My Eye Doctor?
Working closely with your eye care provider can protect your vision. Ask questions and get the information you need to manage your eye health effectively.
Questions to Ask About My Eye Condition:
What is my diagnosis?
What caused this condition?
Is there a treatment available?
How will this affect my vision now and in the future?
Are there any symptoms I should watch for?
Should I make any lifestyle changes?
Questions to Ask About My Treatment:
What treatment will I receive?
When will it begin, and how long will it last?
What are the benefits and success rates of this treatment?
What side effects or risks should I be aware of?
Are there any foods, medications, or activities I should avoid during treatment?
If I miss a dose of my medication, what should I do?
Are there alternative treatment options?
Questions to Ask About My Tests:
What tests will I need?
What will these tests tell us?
When will I receive the results?
Do I need to do anything to prepare for these tests?
Are there any risks or side effects?
Will I need additional tests in the future?
Other Helpful Tips
If you don’t understand something, ask your doctor to explain it in a different way.
Take notes or bring a friend or family member to help you remember the details. You can also use a voice recorder if needed.
Ask your doctor to provide written instructions.
Request printed materials about your condition for reference.
If you still have questions, ask your doctor where to find more information.
Nurses, pharmacists, and other healthcare professionals can also provide helpful insights – don’t hesitate to ask them.
These days, patients play an active role in their healthcare. To protect your vision, stay informed and involved in your eye care.
Loss of Vision
If you have lost some sight from glaucoma, ask your eye care professional about low-vision services and devices that may help you make the most of your remaining vision. Ask for a referral to a specialist in low vision. Many community organizations and agencies offer information about low vision counseling, training, and other special services for people with visual impairments.
How should I use my glaucoma eyedrops?
If your doctor has prescribed eyedrops to treat your glaucoma, it’s important to use them correctly as instructed. Proper use helps your medication work more effectively and lowers the chance of side effects.
To apply your eyedrops the right way, follow these steps:
Wash your hands thoroughly.
Hold the bottle upside down.
Tilt your head back.
Using one hand, hold the bottle close to your eye.
With your other hand, gently pull down your lower eyelid to create a small pocket.
Put the correct number of drops into the pocket. If you are using more than one type of eyedrop, wait at least five minutes before applying the next one.
Close your eye or lightly press on your lower eyelid with your finger for at least one minute. This helps the drops stay in your eye and reduces the chance of them draining into the tear duct, which can lead to side effects.
Mary Watson
