Glaucoma: the silent thief of sight

Finding glaucoma early can help to stop vision loss.


Glaucoma is a complex disease that affects the optic nerve. Learn more about:

  • The two types of glaucoma
  • Risk factors (your chances of getting glaucoma)
  • The many treatments available

How common is glaucoma?

Glaucoma is the leading cause of irreversible (lifelong) blindness. According to the CDC, about 3 million Americans have glaucoma. It’s the second leading cause of blindness worldwide.

Because symptoms often start slowly, many people don’t know they have the disease until later, more advanced stages.

How glaucoma starts

Your eyes continually produce a clear fluid inside the front of the eye called aqueous humor. It nourishes the eye and keeps it healthy. This liquid is different from tears which are outside the eye.

When aqueous humor cannot drain from the eye properly, eye pressure increases. As eye pressure increases, this impairs the retinal nerve in the eyes. This eventually damages the optic nerve.

The optic nerve is a collection of more than a million nerve fibers. These fibers send visual information to the brain. Damage to the optic nerve leads to vision loss.

Changes in vision usually start with a gradual loss in peripheral vision (outside the direct line of sight), while the central vision remains crisp and sharp. Advanced glaucoma can cause "tunnel vision" and lead to blindness.

Types of glaucoma and related symptoms

There are two main types of glaucoma:

  • Open-angle glaucoma
  • Acute (sudden and serious) angle-closure glaucoma

Open-angle glaucoma

With this type of glaucoma:

  • Often there are no symptoms.
  • Once you notice vision loss, it’s likely very advanced.
  • This is the most common type of glaucoma.

Acute angle-closure glaucoma

With this type of glaucoma, symptoms include:

  • Red eye
  • Hazy or blurred vision
  • Halos around lights
  • Severe eye pain and headache
  • Nausea and vomiting
  • Sudden vision loss

Glaucoma risk factors

Older people and some races have greater chances of getting glaucoma, including:

  • Black Americans over age 40
  • Black Americans are six to eight times more likely to get the disease compared to white Americans
  • Adults over age 60 have six times greater risk than younger people, especially Hispanic Americans
  • People of Asian descent and Native Alaskans have an increased risk of angle-closure glaucoma

Other risk factors include:

  • Thin corneas
  • Type 2 diabetes
  • Increased eye pressure
  • Family history of glaucoma
  • Nearsightedness/myopia

All glaucoma treatments reduce intraocular pressure, also known as IOP. A lower IOP is better. A normal pressure ranges from 10 to 21 mmHg. Increased eye pressure is the only risk factor for glaucoma your doctor can offer treatment for.

Glaucoma screening

The American Academy of Ophthalmology suggests that all adults have a complete eye exam by age 40. During this exam, your optometrist or ophthalmologist will screen for glaucoma as well as other eye problems.

A complete exam includes testing:

  • The optic nerve
  • Intraocular pressure, to look for glaucoma
  • The anatomy of drainage angle of your eyes

Your doctor may suggest more tests to screen for glaucoma or other eye problems. Your doctor's suggestions will be based on your exam results and risk factors. Your doctor will also let you know how often you should have eye exams.

If you need more tests for glaucoma, they may include:

  • Measuring corneal thickness
  • Measuring retinal nerve fiber layer thickness
  • A visual field test to measure your peripheral vision

These measurements can help find out your chances of getting glaucoma. They can also tell us if you have eye damage due to glaucoma.

Glaucoma treatments

There is no treatment to completely heal from glaucoma, but many treatments can help. Treatments can help to reduce eye pressure which can help stop further vision loss. Treatments include:

  • Medication
  • Laser procedure (simple surgery)
  • Other types of surgery


Several types of topical medications (eye drops) can help lower IOP by decreasing fluid production and/or increasing fluid outflow. Talk with your doctor about finding the right medication if you:

  • Have heart or lung disease
  • Are allergic (have a bad response) to sulfa drugs

Laser procedures

Laser trabeculoplasty is a quick and painless in-office procedure. It can help lower IOP in about 80% of patients who have it.

Although you can have positive results after this procedure, the condition can still worsen over time. But the procedure is low risk and can be repeated. A laser iridotomy is another laser treatment.


Surgery lowers IOP by opening the eye’s existing fluid drainage pathway. This opening bypasses the natural drainage to create a new pathway for fluid to drain from the eye.

Over the last 10 years, several new surgical procedures have been developed known collectively as Minimally Invasive Glaucoma Surgery (MIGs). These procedures help reduce eye pressure. The procedures are safer than traditional glaucoma surgery.

Your doctor will talk to you about treatment options if you need surgery.

We're here to help

As with many health problems, finding glaucoma early is important. All patients age 40 and over should have a complete eye exam. Your eye doctor will tell you how often you should have eye exams based on your risk factors.

If glaucoma is found and treated early, vision loss and blindness can often be stopped.

To schedule an appointment, contact Glaucoma Consultants Northwest at The Polyclinic at 1-206-682-3447.

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The information provided is for general informational purposes only and is not intended to be medical advice or a substitute for professional health care. You should consult an appropriate health care professional for your specific needs.