Glaucoma is a group of eye diseases that cause damage to the optic nerve. The optic nerve is the part of the eye that carries the images we see to the brain. Glaucoma is often called the silent thief of sight, gradually stealing vision without warning, and often without symptoms. If left untreated, glaucoma can lead to blindness. It was once thought that elevated pressure inside the eye was the main cause of optic nerve damage. Although elevated pressure is clearly a risk factor, we now know that other factors must also be involved, because even people with normal pressure, can experience vision loss from glaucoma.

What is glaucoma?

Glaucoma is a group of diseases that can damage the eye’s optic nerve and result in vision loss and blindness. Glaucoma occurs when the normal fluid pressure inside the eyes slowly rises. However, with early glaucoma treatment and primary eye care, you can often protect your eyes against serious vision loss.

What causes glaucoma? 

There is a small space in the front of the eye called the anterior chamber. This area holds clear fluid that flows in and out of the chamber. The fluid is important to nourish and moisten nearby tissues. If the fluid doesn’t drain properly, then it could mean that pressure is building up. Eventually, the increase in pressure causes damage to the optic nerve.

Even though the pressure builds up, it doesn’t always cause the same level of damage to the optic nerve. The damage varies from one person to the next. Some people experience optic nerve damage due to low pressure levels, while others don’t experience the damage until a high pressure level has built up.

What is the optic nerve?

The optic nerve is a bundle of more than 1 million nerve fibers. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision. What are some other forms of glaucoma? Open-angle glaucoma is the most common form. Some people have other types of the disease.

Low-tension or normal-tension glaucoma. Optic nerve damage and narrowed side vision occur in people with normal eye pressure. Lowering eye pressure at least 30 percent through medicines slows the disease in some people. Glaucoma may worsen in others despite low pressures. A comprehensive medical history is important in identifying other potential risk factors, such as low blood pressure, that contribute to low tension glaucoma. If no risk factors are identified, the treatment options for low-tension glaucoma are the same as for open-angle glaucoma.

Angle-closure glaucoma. The fluid at the front of the eye cannot reach the angle and leave the eye. The angle gets blocked by part of the iris. People with this type of glaucoma have a sudden increase in eye pressure. Symptoms include severe pain and nausea, as well as redness of the eye and blurred vision. If you have these symptoms, you need to seek treatment immediately because it is a medical emergency. If your doctor is unavailable, go to the nearest hospital or clinic. Without glaucoma treatment to improve the flow of fluid, the eye can become blind in as few as one or two days. Usually, prompt laser surgery and medicines can clear the blockage and protect sight.

Congenital glaucoma. Children are born with a defect in the angle of the eye that slows the normal drainage of fluid. These children usually have obvious symptoms, such as cloudy eyes, sensitivity to light, and excessive tearing. Conventional surgery typically is the suggested treatment, because medicines may have unknown effects in infants and be difficult to administer. Surgery is safe and effective. If surgery is done promptly, these children usually have an excellent chance of having good vision.

Secondary glaucomas. These can develop as complications of other medical conditions. These types of glaucomas are sometimes associated with eye surgery or advanced cataracts, eye injuries, certain eye tumors, or uveitis (eye inflammation). Pigmentary glaucoma occurs when pigment from the iris flakes off and blocks the meshwork, slowing fluid drainage. A severe form, called neovascular glaucoma, is linked to diabetes. Corticosteroid drugs used to treat eye inflammation and other diseases can trigger glaucoma in some people. Glaucoma treatment includes medicines, laser surgery, or conventional surgery.

How does open-angle glaucoma damage the optic nerve 

In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of the chamber and nourishes nearby tissues. The fluid leaves the chamber at the open angle where the cornea and iris meet. When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye. Sometimes, when the fluid reaches the angle, it passes too slowly through the meshwork drain. As the fluid builds up, the pressure inside the eye rises to a level that may damage the optic nerve. When the optic nerve is damaged by increased pressure, open-angle glaucoma (and vision loss) may result. That’s why controlling the pressure inside the eye is important.

Does increased eye pressure mean that I have glaucoma? 

Not necessarily. Increased eye pressure means you are at risk but does not mean you have the disease. A person has glaucoma only if the optic nerve is damaged. If you have increased eye pressure but no damage to the optic nerve, you do not have this disease. However, you are at risk. Follow the glaucoma treatment advice of your primary eye care professional.

Can I develop glaucoma if I have increased eye pressure?

Not necessarily. Not every person with increased eye pressure will develop glaucoma. Some people can tolerate higher eye pressure better than others. Also, a certain level of eye pressure may be high for one person but normal for another. Whether you develop glaucoma depends on the level of pressure your optic nerve can tolerate without being damaged. This level is different for each person. That’s why a comprehensive dilated primary eye care exam is very important. It can help your primary eye care professional determine what level of eye pressure is normal for you.

Can I develop glaucoma without an increase in my eye pressure?

Yes. This disease can develop without increased eye pressure. This form is called low-tension or normal-tension glaucoma. It is not as common as open-angle glaucoma.

Who is at risk for glaucoma?

Anyone can develop this disease. Some people are at higher risk than others. They include:

– African Americans over age 40.
– Everyone over age 60, especially Mexican Americans.
– People with a family history.

Among African Americans, studies show that glaucoma is:

– Five times more likely to occur in African Americans than in Caucasians.
– About four times more likely to cause blindness in African Americans than in Caucasians.
– Fifteen times more likely to cause blindness in African Americans between the ages of 45-64 than in Caucasians of the same age group.

A comprehensive dilated eye exam can reveal more risk factors, such as high eye pressure, the thinness of the cornea, and abnormal optic nerve anatomy. In some people with certain combinations of these high-risk factors, medicines in the form of eyedrops reduce the risk of developing the disease by about half.

Medicare covers an annual comprehensive dilated primary eye care exam for some people at high risk for the eye disease.

What can I do to protect my vision?

Studies have shown that the best way to control the disease is early detection and treatment of glaucoma before it causes major vision loss. So, if you fall into one of the high-risk groups for the disease, make sure to have your eyes examined through dilated pupils every one to two years by your primary eye care professional.

If you are being treated, be sure to take your medicine every day. See your Chicago optometrist regularly.

You also can help protect the vision of family members and friends who may be at high risk: African Americans over age 40; everyone over age 60, especially Mexican Americans; and people with a family history of the disease. Encourage them to have a primary eye care exam at least once every two years. Remember: Lowering eye pressure in glaucoma’s early stages slows progression of the disease and helps
save vision.

What are the symptoms of glaucoma?

At first, there are no symptoms. Vision stays normal, and there is no pain. However, as the disease progresses, a person may notice his or her side vision gradually failing. That is, objects in front may still be seen clearly, but objects to the side may be missed. As the disease remains untreated, people may miss objects to the side and out of the corner of their eye. Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. They seem to be looking through a tunnel. Over time, straight-ahead vision may decrease until no vision remains. This problem can develop in one or both eyes.

How is glaucoma detected?

This eye disease is detected through a comprehensive eye exam that includes:

– Visual acuity test: This eye chart test measures how well you see at various distances. A tonometer measures pressure inside the eye to detect the disease.
– Visual field test: This test measures your side (peripheral) vision. It helps your eye care professional tell if you have lost side vision, a sign of glaucoma.
– Dilated eye exam: Drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
– Tonometry: An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
– Pachymetry: A numbing drop is applied to your eye. Your eye care professional uses an ultrasonic wave instrument to measure the thickness of your cornea.

Will I go blind if I have this disease?

The best option to protect your vision is to identify the presence of the disease at an early stage. An early diagnosis can be treated to minimize the vision loss that occurs. If the eye disease is left untreated, then it could potentially affect vision. Usually, peripheral vision is affected before the central vision is damaged.

How can I prevent glaucoma?

Researchers are trying to determine the cause of the disease so that this information can be used to treat the eye disease. At this point, it is unclear if glaucoma can be prevented. But, maintaining a healthy lifestyle might be a solution to reduce the risk of eye disease.

Current research has shown that people who eat a nutrient-rich diet, maintain a healthy weight, and avoid excessive alcohol and smoking can protect their overall health and vision.

Additionally, it is important to maintain regular primary eye care exams with an experienced team. These primary eye care appointments will provide the opportunity to identify early symptoms that need to be treated.

What are the symptoms of glaucoma?

Most patients don’t have any symptoms until they start to experience vision loss. Since you won’t recognize any signs of the disease, it is essential to visit a primary eye care doctor regularly to identify the eye condition before you experience vision loss. A Chicago optometrist can detect and treat the disease before it results in damage to the optic nerve.

Can glaucoma be cured?

The damage to the optic nerve can’t be reversed. So, there is no cure after the damage has occurred. The lack of a cure is the most important reason why you should maintain regular eye exams. If you have been diagnosed with this disease, then it is important to follow the recommendations for glaucoma treatment to prevent severe vision loss.

Can glaucoma patients have LASIK?

If you are being treated for glaucoma, then you probably aren’t a good candidate for LASIK vision correction. During the surgery, a suction device is used to help with the creation of a corneal flap. When the suction is happening, it briefly increases the IOP.

Even though patients usually can’t have LASIK, there are other options available. Talk to a Chicago optometrist about PRK if you would like vision correction surgery.