A Concise Guide to Glaucoma

Glaucoma diagnosis chartEach year, World Glaucoma Week raises awareness of glaucoma, a chronic, degenerative disorder of the optic nerve. It’s essential to stay informed about this topic because glaucoma can cause people to lose vision.

Also known as the “silent blinding disease,” glaucoma’s early symptoms are often unnoticeable. Without comprehensive routine vision care, many individuals do not know they have it until after potentially irreversible vision damage has occurred.

There are also multiple types of glaucoma, some of which are related to other eyesight disorders and diseases (known as “secondary” glaucomas. “Primary” glaucomas develops unrelated to other conditions). These facts make it clear that glaucoma is still not a widely enough recognized disease, even though the World Health Organization estimates that about 94 million people globally have blindness caused by glaucoma.

What Is Glaucoma?

A group of eye diseases that cause progressive damage to the optic nerve, glaucoma usually happens when fluid builds up in the front part of the eye, which increases pressure to harmful levels. This issue is often painless, so patients may not know it is occurring until optic nerve damage is severe enough to cause vision loss.

While some people are born with glaucoma or develop it in infancy or childhood, it mainly begins for most patients after they’ve had their 40th birthday. It is often considered a disease related to aging. In fact, glaucoma is the leading cause of blindness in patients over age 60, according to survey data from the American Academy of Ophthalmology.

Our library of glaucoma videos helps to illustrate what happens as glaucoma takes hold and also shows what you can do to reduce your chances of experiencing optic nerve damage. We invite you to watch these educational videos.

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Two established types of glaucoma occur most commonly. They are known as Primary Open-Angle Glaucoma (POAG) and Angle-Closure Glaucoma (ACG). There are also several other types of glaucoma, including Normal-Tension Glaucoma, Pigmentary Glaucoma, and Congenital Glaucoma, almong others.

Primary Open-Angle Glaucoma

Primary open-angle glaucoma is the most common type of glaucoma. This type of glaucoma occurs gradually due to the eye not draining excess fluid, called aqueous humor, as well as it should (like a clogged drain). This fluid flows freely through the structure in a healthy eye, known as the drainage angle. With POAG, pressure in your eye builds due to poor drainage, and the optic nerve becomes damaged.

Angle-Closure Glaucoma

Also known as “closed-angle glaucoma” or “narrow-angle glaucoma,” this type of disease occurs when your iris (the colored part of your eye) is too close to the drainage angle (known as the trabecular meshwork) and blocks it. Some individuals’ eyes are naturally structured this way and simply have a higher risk of developing this more acute form of glaucoma.

While POAG is the “silent” form of glaucoma, ACG shouts loudly in the way of sudden blurry vision and intense eye pain. And even those these acute attacks happen quickly, many people develop this type slowly. This form of ACG is called Chronic Angle-Closure Glaucoma. ACG is a true eye emergency, and you must see an eye care specialist immediately to prevent total vision loss, which can happen rapidly.

Normal-Tension Glaucoma

A third type of glaucoma is called Normal-Tension Glaucoma. It’s sometimes called “low-tension glaucoma” or “normal-pressure glaucoma” because the optic nerve is damaged, despite eye pressure not being very high. A person at higher risk of glaucoma with normal pressure include those with a family history of Normal-Tension Glaucoma, people with Japanese ancestry, and people with a history of systemic heart disease. Doctors don’t know why this type happens.

An image showing the differences between a normal eye and one with glaucoma.

Secondary Glaucoma

As mentioned earlier, Secondary Glaucomas are any form of glaucoma in which a known disease or disorder results in increased eye pressure that results in optic nerve damage. It can be caused by eye injury, tumors, inflammation, advanced cases of cataracts or diabetes, and certain drugs, such as steroids. Treatment for Secondary Glaucomas depends on whether it’s the open-angle or angle-closure type of glaucoma.

Pseudoexfoliation Glaucoma

Some patients with a disease called Exfoliation Syndrome or Pseudoexfoliation (PEX) develop glaucoma. This disease causes an abnormal accumulation of protein in the eye’s drainage structures, causing the pressure to rise and damage the optic nerve. Pseudoexfoliation Glaucoma is more common in people from Russia, Nordic countries, Greece, Mediterranean countries, India, and others. It’s more likely to occur in people over 70, particularly women.

Pigmentary Glaucoma

A secondary glaucoma, Pigmentary Glaucoma—sometimes called “pigmentary dispersion syndrome”— occurs when the pigment cells fall off from the back of the iris and float around in the aqueous humor. Over time, these cells flow towards the drainage canals in the eye and clog them, which causes the eye pressure to rise.

Primary Juvenile Glaucoma

Primary Juvenile Glaucoma occurs in patients between the ages of three and 40. This rare type of glaucoma is caused by abnormalities in the drainage canals in the eye and appears in the earlier years of life. It’s a primary type of glaucoma but is often detected late after the damage has already occurred to the optic nerve and eye pressure is above normal. Surgery is a common treatment for Primary Juvenile Glaucoma.

Uveitic Glaucoma

The middle layer of the eye is called the uvea. This part of the eye provides most of the blood supply to the retina. When this part of the eye is swollen or inflamed, it’s called uveitis. The inflammation itself or the medications used to treat it (steroids) causes the pressure in the eye to rise, leading to Uveitic Glaucoma.

Congenital Glaucoma

Congenital Glaucoma occurs in babies when the development of the eye’s drainage canals during the prenatal period does not complete or forms incorrectly. This condition is rare and may be inherited. In uncomplicated cases, microsurgery can correct the structural defects. Other times, medication and more advanced surgery are needed.


As we learned in the case of Normal-Tension Glaucoma, glaucoma can develop despite having normal eye pressure. The only way to best understand your risk for developing the condition is to keep up with yearly eye exams.

Other risk factors include being over age 40 and having a family history of the disease. You may also have a higher risk if you:

  • are farsighted or nearsighted
  • are of African, Hispanic, or Asian descent
  • are on long-term steroid medications
  • suffer from diabetes (which can lead to other eye diseases, including diabetic retinopathy), migraines, high blood pressure, or poor circulation
  • have had an eye injury in the past
  • have specific eye structural differences, like corneas that are thin at the center, thinning of the optic nerve, or the ACG-trigger in which the iris is located too close to the drainage angle.

The Symptoms of Glaucoma

There are virtually no symptoms associated with Primary Open-Angle Glaucoma in its earliest stages. However, patients may begin to notice blind spots in their peripheral vision as the disease worsens.

If an acute “attack” occurs, Angle-Closure Glaucoma will cause a number of symptoms that are difficult to ignore. You should seek medical attention right away if you’re experiencing:

  • severe eye or forehead pain/sudden headache
  • eye redness
  • decreased or blurred vision
  • visual disturbances that look like rainbows or halos
  • nausea and vomiting

Disease Progression If Left Untreated

The eventual result of POAG or even Normal-Tension Glaucoma is irreversible blindness, starting with your side vision (called peripheral vision). With ACG, vision loss can occur very quickly if emergency eye care is not sought during an acute attack.

How to Treat Glaucoma

It is imperative to remember that damage caused by glaucoma is permanent, and there is no cure for the disease today. However, your eye doctor can offer you medication (typically eye drops) or surgery (traditional or laser) to halt or slow down vision loss. You’ll want to discuss your treatment options with your doctor to decide which best fits your lifestyle and addresses your individual experience with glaucoma.

How to Prevent Glaucoma

While glaucoma is unavoidable for some, early intervention can ensure that the disease does not cause vision loss. The only way to know whether you’re at risk for glaucoma or are experiencing the earliest stages of the disease is through routine eye care. Your eye doctor has advanced tools available to test for glaucoma.

Glaucoma Testing

A woman gets her eyes examined at a doctor’s office.While testing your eye pressure is part of a routine examination and can tell your doctor whether yours may be dangerously high, there is more to a complete glaucoma screening. During glaucoma testing, your ophthalmologist will also:

  • inspect your eye’s drainage angle
  • examine your optic nerve for damage
  • take images or a computer measurement of your optic nerve
  • test your peripheral (side) vision
  • measure your cornea’s thickness

You Can Prevent or Manage Glaucoma

While there is no cure yet for glaucoma, organizations like the Glaucoma Research Foundation are working to find effective ways to prevent, manage, and even cure glaucoma. Campus Eye Center is recognized as one of the best resources in Lancaster, PA, for helping patients live better by seeing better. If you are concerned about your risk of developing glaucoma or have already been diagnosed and are seeking an experienced, compassionate doctor to help you work through treatment options, please contact us at Campus Eye Center to make an appointment today.