Glaucoma FAQs

Glaucoma refers to a group of diseases that damage the optic nerve, which carries visual information from the back of the eye to the brain. Risk factors for glaucoma include age, family history, the shape of the eye, race/ethnicity, and increased eye pressure. Although glaucoma may not have symptoms in the beginning, eventually permanent vision loss can occur.

It is estimated that more than 3 million Americans have glaucoma, some of whom are undiagnosed. Studies estimate that 2-3% of Americans over age 40 have Glaucoma.

Elevated eye pressure increases the risk of having glaucoma. However it is also possible to have glaucoma with average or below average eye pressure (often termed normal tension glaucoma).Therefore eye pressure is one of the ‘vital signs’ of a glaucoma check-up but does not define glaucoma. Decreasing eye pressure is the only way we currently know to decrease the onset or progression of glaucoma related vision damage. Therefore the treatments for glaucoma, including medications, lasers and surgeries, all work towards lowering eye pressure. Many patients ask what is the most ideal eye pressure. This is a complicated patient and depends on many personal factors. While the average eye pressure across the population is 15.5mmHg, the ideal eye pressure for each patient is different and warrants discussion with one’s doctor.

There are several types of glaucoma that include open angle, closed angle, secondary glaucoma, and pediatric glaucoma. Click here to learn more about the types of glaucoma.

Any individual who has findings that are suspicious for glaucoma without definite signs of glaucoma damage. Often this means the patient may have optic nerve characteristics suggestive of glaucoma, but does not have corresponding changes on visual field testing. Depending on the degree of suspicion, glaucoma suspects may be monitored carefully with routine testing and exams or treated.

For most people with glaucoma, there are no warning signs or noticeable changes in vision until the disease has silently and gradually worsened to a severe stage. About half of those with glaucoma do not yet know they have it. This is why glaucoma is often called the “thief of sight” and one of the main reasons why it is still one of the leading causes of blindness in the world.

In the early stages, glaucoma typically affects peripheral (or side) vision. A common misconception is that those with glaucoma get tunnel vision. Tunnel vision is almost never the way patients experience their glaucoma. Instead, vision changes start with a very subtle blurring which usually begins near the nose. Since we see with both eyes at the same time, vision lost in one eye is often covered up and hidden by the other eye. If left untreated, areas of vision loss will slowly spread and may go unnoticed until it reaches the central vision. Click here to learn more.

Glaucoma can affect anybody, which is why regular screenings are important. Because the symptoms of glaucoma can be mild, or even non-existent, it is recommended that individuals get a baseline screening at the age of 40. Some factors suggest a higher risk and may require earlier or more frequent screening, including:

• Those who are aged 60 or older;
• Those who have a family history of glaucoma;
• Those who are of African American, Latino, or Asian descent;
• Those who are significantly near-sighted;
• Those who have risk factors based on eye exam, such as elevated eye pressure, narrow angles, or particular optic nerve findings.

How often a glaucoma screening exam should be performed will be determined by the results of your initial exam.

The best way to test for glaucoma is through a comprehensive eye exam with an ophthalmologist which includes evaluation of your angle (gonioscopy), and your optic nerve with dilation if appropriate. Additionally, a visual field test and optic nerve photograph or analysis may also be performed. Please refer to our page on ‘What to expect' for further information.

The primary function of the visual field test is to measure the patient’s peripheral (side) and central vision. This test can find areas of vision loss that may not be noticeable to the patients on their own. During the test, lights of varying brightness appear in different parts of the machine while the patient’s eye is focused on a central spot. The patient clicks a button with each light that they see. The results are compared to test results of people of a similar age. Results are also compared to prior results from the same patient. The test is repeated to check for possible changes over time.

This varies based on the type and degree of glaucoma you have. This may range from every 3 months to every year in stable patients or more often if there are concerning findings.

The type of surgery that is best suited for a particular patient is based on many factors such as the type of glaucoma, eye pressure goal, shape of the eye, prior eye surgeries, amongst other factors. Therefore it is best to discuss whether you are a candidate for a particular type of surgery with your doctor. To learn more about the most common surgical options, including minimally invasive glaucoma surgery (MIGS) please refer to our Glaucoma Surgery page.

There are many methods for administering eye drops.The AAO website  highlights important tips along with an instructional video. If you have any questions, feel free to ask your doctor.

Side effects vary amongst drops and can range from irritation, redness, burning, blurry vision to more general symptoms such as shortness of breath, low blood pressure, fatigue, dizziness, sleep disturbance, and change in taste. Further details are listed here.

There is not strong enough evidence to support alternative therapies for glaucoma, although we are hopeful for the future. Currently all treatments center around lowering eye pressure to decrease the risk of glaucoma onset or glaucoma progression.

The American Glaucoma Society and American Academy of Ophthalmology do NOT recommend marijuana or CBD (cannabidiol) use for glaucoma treatment. The reasons for this are multifold:

1. There have been recent studies that suggest the eye pressure could even be higher with use of these substances, and therefore may cause harm.
2. Some studies had found that marijuana may decrease eye pressure, however even if this was the case, a patient would have to consume marijuana frequently (close to every 4 hours) to have a sustained effect.
3. There is not enough evidence to support the use of marijuana or CBD in glaucoma patients. The existing medical, laser, and surgery options for glaucoma have been studied more intensively and have a better likelihood of success, as well as safety, at this time.

We do not currently have a way to reverse the vision loss from glaucoma. However it may be beneficial to see a low vision specialist. Low vision specialists can help patients make the most of their vision by employing additional tools or techniques. The American Academy of Ophthalmology has a handout and video that outlines how low vision services may be beneficial to patients.

A small subset of patients will unfortunately become legally blind from glaucoma. However keeping up with medications/treatment and the follow up plan will decrease the risk of glaucoma progression and blindness.

Unfortunately the vision loss from glaucoma is not reversible. Therefore it is important to prevent blindness by diagnosing and treating glaucoma as aggressively as possible early on.