What Is Glaucoma?
Glaucoma is an eye disease that can damage your optic nerve and can cause blindness. The optic nerve carries visual information to your brain from your eyes.
Glaucoma is often, but not always, occurs due to abnormally high pressure inside your eye. Over time, the increased pressure can abrade your optic nerve tissue, which may cause vision loss or even blindness. If it’s detected early, you may be able to prevent additional vision loss.
What Are the Symptoms of Glaucoma?
The most common type of glaucoma is primary open-angle glaucoma. It has no signs or symptoms except slow vision loss. For that reason, it’s necessary that you go to yearly comprehensive eye exams so your ophthalmologist, or eye specialist, can observe any changes in your vision.
Acute-angle closure glaucoma, which is also known as narrow-angle glaucoma, is a medical emergency. See your doctor urgently if you notice any of the following symptoms:
- severe pain in eyes
- redness in your eye
- unexpected vision disturbances
- seeing colored rings around lights
- sudden blurred vision
What Causes Glaucoma?
The back of your eye constantly makes a clear fluid called aqueous humor. As this fluid is made, it fills the front part of your eye. Then, it leaves your eye through channels in your cornea and iris. If these channels are blocked or partly obstructed, the natural pressure in your eye, which is known as the intraocular pressure (IOP), may raise. As your IOP increases, your optic nerve may become damaged. As damage to your nerve proceeds, you may start losing vision of your eye.
What causes the increase of pressure in your eye to isn’t always clear. However, specialists believe one or more of these factors may have a role:
- dilating eye drops
- blocked or restricted drainage in your eye
- medications, such as corticosteroids
- poor or decreased blood flow to your optic nerve
- high or raised blood pressure
What Are the Types of Glaucoma?
Five major types of glaucoma are known. These include:
Open-Angle (Chronic) Glaucoma
Open-angle, or chronic, glaucoma has no signs or symptoms other than gradual vision loss. This loss may be too slow and your vision can suffer irreversible damage before any other signs become visible. According the National Eye Institute (NEI), this is the most common type of glaucoma.
Angle-Closure (Acute) Glaucoma
If the flow of your aqueous humor fluid is suddenly blocked, the rapid buildup of fluid may lead to a severe, sudden, and painful increase in pressure. Angle-closure glaucoma is an emergency situation. You should call your doctor urgently if you begin noticeing symptoms, such as severe pain, nausea, and blurred vision.
Children born with congenital glaucoma have a defect in the angle of their eye, which retards or prevents normal drainage of fluid. Congenital glaucoma generally presents with symptoms, such as cloudy eyes, heavy tearing, or sensitivity to light. Congenital glaucoma can pass in families.
Secondary glaucoma is usually a side effect of injury or another eye condition, such as cataracts or eye tumors. Medicines, such as corticosteroids, may also cause this type of glaucoma. Rarely, eye surgery can lead to secondary glaucoma.
Normal Tension Glaucoma
In some cases, people without increased eye pressure have damage to their optic nerve. The cause of this isn’t clear. However, extreme sensitivity or a lowering of blood flow to your optic nerve may be a cause in this type of glaucoma.
Who Is at Risk of Glaucoma?
According to the World Health Organization (WHO), glaucoma is the second major cause of blindness all over the world. The risk factors for glaucoma are:
People over 60 have higher risk of glaucoma, warns the NEI, and the risk of glaucoma increases gradually with each year of age. If you’re African-American, your increase in risk starts at 40 years of age.
African-Americans or people of African descent are remarkably more likely to develop glaucoma than Caucasians. People of Asian descent have more chances of developing angle-closure glaucoma, and people of Japanese descent are at a higher risk of developing low-tension glaucoma.
Chronic eye inflammation and thin corneas can cause increased pressure in your eyes. Physical injury or trauma to your eye, such as being hit in your eye, can also cause increase of pressure in your eye.
Some types of glaucoma may travel in families. If your parent or grandparent had open-angle glaucoma, you’re at an high risk of developing the condition.
People with diabetes and those with high blood pressure and heart disease are at high risk of developing glaucoma.
Use of Certain Medicine
Using corticosteroids for large periods may increase your risk of developing secondary glaucoma.
How Is Glaucoma Diagnosed?
To diagnose glaucoma, your ophthalmologist will want to do a comprehensive eye examination. They’ll check for signs of damage including loss of nerve tissue. They may also use one or more of the given tests and procedures:
Detailed Medical History
Your doctor will want to know what symptoms you’ve been facing and if you have any personal or family history of glaucoma. They’ll also ask for a general health evaluation to determine if any other health conditions may be affecting your eye health, such as diabetes or high blood pressure.
This class of tests measures internal pressure of your eye.
People with thin corneas have more chances of developing glaucoma. A pachymetry test can reveal your doctor if your corneas are thinner than average.
This test, also called a visual field test, can tell your doctor if glaucoma is impacting your vision by measuring your peripheral, or side, vision and your central vision.
Monitoring Your Optic Nerve
If your doctor wants to monitor for slow changes to your optic nerve, they may take photographs of your optic nerve to perform a side-by-side comparison over time.
How Is Glaucoma Treated?
The target of glaucoma treatment is to decrease IOP to prevent any additional eyesight loss. Normally, your doctor will start treatment with prescription eye drops. If these don’t work or more advanced treatment is required, your doctor may recommend one of the following treatments:
Various medicines made to lower IOP are available. These medicines are available in the form of eye drops or pills, but the drops are more common. Your doctor may recommend one or a combination of these.
If a blocked or partially obstructed channel is causing increased IOP, your doctor may recommend surgery to make a drainage path for fluid or destroy tissues that are responsible for the raised fluid.
Treatment for angle-closure glaucoma is different. This type of glaucoma is a medical emergency and needs urgent treatment to decrease eye pressure as rapidly as possible. Medicines are often tried first, to reverse the angle closure, but this may be unsuccessful. A laser procedure called laser peripheral iridotomy may also be performed. This procedure makes small holes in your iris to allow for increased fluid movement.
Will a Person with Glaucoma Go Blind?
If your raised IOP can be stopped and the pressure came back to normal, vision loss can be slowed or even stopped. However, because there’s no cure for glaucoma, you’ll probably need treatment throughout your life to regulate or control your IOP. Unfortunately, vision lost as a result of glaucoma cannot be restored.
Can Glaucoma Be Prevented?
Glaucoma can’t be prevented, but it’s still essential to detect it early so you can start treatment that will help prevent it from getting worse. The best way to determine any type of glaucoma early is to have an annual preventive eye care appointment. Make an appointment with an ophthalmologist. Simple tests performed during these routine eye checks may be able to find damage from glaucoma before it becomes severe and starts causing vision loss.
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- Glaucoma is the second leading cause of blindness globally. (2004, November 1)
- Mayo Clinic Staff. (2015, September 15). Glaucoma