of people with glaucoma don’t even know they have it. That’s really worrisome since this sneaky eye disease can slowly erode your vision, potentially leading to irreversible blindness.
Glaucoma is more common in older adults, but it can certainly occur in younger people. Globally, glaucoma affects 3.5% of people ages 40–80 years old
. Early detection and proper management of the condition are essential to protect your eyes.
What is glaucoma?
Glaucoma is a disease that damages the eye’s optic nerve, which sends visual images to your brain. The predominant type of glaucoma is primary open-angle glaucoma and is the focus of this article. Glaucoma causes the gradual loss of eyesight, usually starting with peripheral (side) vision.
The main risk factor
for glaucoma is elevated fluid (aqueous humor) pressure in the eyeball. This is called intraocular pressure. Just as for a basketball, you want enough pressure in the eye but not too much.
Fluid pressure can build up in the eye when there’s an imbalance between the formation of aqueous humor and its drainage. This extra pressure can push against your optic nerve and damage nerve cells needed for vision.
Your eye doctor uses a special instrument called a tonometer to measure the pressure in each eye. “Normal” eye pressure is generally considered 10 to 21 millimeters of mercury (mmHg)
That said, not everyone with glaucoma has “high” eye pressure. In fact, 30% or more
of people with glaucoma worldwide have normal eye pressure (this is sometimes called normal-tension glaucoma). Yet, damage to the optic nerve may still occur, which can be detected in a dilated eye exam.
Perhaps the most frustrating thing about glaucoma is that it’s not really clear what causes it. Your genetics can play a role, and the disease tends to run in families. But there’s more to it than that.
shows similarities between the ways that nerve cells die in glaucoma and Alzheimer’s disease. A German study
found that 26% of nursing home residents with Alzheimer’s also had glaucoma. But only 5% of residents without Alzheimer’s had the eye disease. More research is needed in this area.
Glaucoma symptoms to know
Glaucoma is a tricky eye disease. You can’t “feel” high eye pressure. And early symptoms may be overlooked
until you lose a significant amount of vision. That has earned glaucoma the moniker the “sneak thief of sight.”
As glaucoma progresses, you may notice
- Needing more light to see well
- Poor night vision
- Blurry/dim vision
- Increased problems with glare, such as from headlights
- Trouble seeing objects off to either side (declining peripheral vision)
- Letters appearing faded when reading
- Areas of vision that are darker or missing
These types of visual changes can reduce your quality of life
and eventually erode your independence. So, it’s important to do everything you can to control the disease. Fortunately, comprehensive exams with your eye doctor can help catch it early so you can start treatment.
How to treat glaucoma
A mainstay of glaucoma treatment is prescription eye drops to lower eye pressure (even in cases of normal-tension glaucoma). These are placed in the eyes one or more times a day, as prescribed by your eye doctor.
Unfortunately, approximately 70% of topical eye products contain a preservative called benzalkonium chloride
(BAK), which can irritate the eyes
. In recent years, preservative-free glaucoma eye drops
have become more widely available. These are gentler on the eyes
Just be aware that preservative-free eye drops typically cost significantly more and receive limited insurance coverage. They’re sold in single-use vials (rather than a multi-dose bottle) to avoid issues with bacterial contamination. If you take preservative-free eye drops, check the website of the company that makes them, as you might find a discount card online.
If preservative-free eye drops don’t fit your budget, your eye doctor may be able to prescribe an eye drop with less harsh preservatives
In some cases of glaucoma, laser therapy or surgical procedures may be used to improve fluid drainage and lower eye pressure. Still, none of the current therapies for glaucoma can “cure” the disease. The main goal of treatment is to slow or stop vision loss.
Checking eye pressure
If you have glaucoma, your eye doctor will periodically check your eye pressure. But eye pressure fluctuates throughout the day and night. Only measuring eye pressure in the doctor’s office a few times a year may not give the most accurate picture.
Increasingly, experts are looking at how to equip glaucoma patients with their own eye pressure measuring device — similar to how people with high blood pressure or high blood sugar can monitor themselves at home.
The FDA has approved
a handheld device for home eye pressure monitoring
, as well as a “smart” contact lens
to monitor eye pressure over a 24-hour period. These home-monitoring devices are not yet commonly used, and insurance coverage is limited. But they’re exciting new developments in glaucoma care.
Home monitoring could provide a way to help identify why some glaucoma patients lose vision despite having well-controlled eye pressure when checked at the doctor’s office. Moreover, it might help individuals pinpoint specific lifestyle factors that raise or lower their eye pressure.
How to prevent glaucoma & manage it
As with many chronic diseases, healthy lifestyle habits may help control glaucoma. These should not replace conventional glaucoma treatments, as the risk of vision loss is too great to rely on lifestyle approaches alone. But they can be added to your doctor-prescribed treatment.
Consider adding these strategies to your regimen to help prevent or control glaucoma:
Eat leafy greens and beets
suggests that higher intake of nitrate-rich veggies may reduce the risk of developing glaucoma by 20–30%. Beets
and dark leafy greens like kale
are some of the best dietary sources of nitrate, which your body can use to make nitric oxide. This signaling molecule promotes drainage of fluid from the eye, which could help lower eye pressure. People with glaucoma have reduced levels of nitric oxide signaling in their eyes. Notably, a prescription eye drop
that promotes nitric oxide signaling is also now available (but not in a preservative-free version).
has found a link between higher carbohydrate intake and an increased risk of glaucoma. Plus, an observational study
suggests that a low-carb diet that focuses on plant-based fat and protein may decrease risk of glaucoma. Though more research is needed in this area, certainly other studies suggest benefits of low-carb and ketogenic diets
for reducing the risk of various health problems, including Alzheimer’s disease, as we age. Just be sure to keep the diet healthy, with plenty of colorful low-carb vegetables.
Avoid excessive caffeine
Coffee, unless decaffeinated, is particularly rich in caffeine. In some people with glaucoma, caffeine increases eye pressure approximately 2 mmHg in the few hours after its consumption. This is likely because it can stimulate the production of aqueous fluid
in the eye. Each 1 mmHg rise in eye pressure has been associated with a 10% higher risk of glaucoma development and progression
Enjoy moderate aerobic exercise
Activities such as walking, jogging, and bicycling
may help lower eye pressure. In one recent study
, people with glaucoma were asked to jog on a treadmill for 30 minutes at moderate intensity. Their eye pressure dropped by more than 2 mmHg, which was measured right after exercise. However, yoga moves that involve head-down positions
, such as headstands, may best be avoided, as they can rapidly increase eye pressure by 6 to 11 mmHg. Holding your breath during exercise, such as while weight lifting
, may also raise eye pressure.
Mindfulness meditation, such as taking time out to focus on your breathing, has long been promoted as a way to manage stress. Newer research
suggests it may also help manage glaucoma. Mental stress raises the body’s secretion of cortisol, a hormone that can increase eye pressure. Focusing on slow breathing counteracts the stress response. Moreover, studies
show meditation can help lower eye pressure in both normal-pressure and high-pressure glaucoma. Some people enjoy diffusing essential oils during meditation.
Take a break from screens
Heavy computer use
is associated with increased glaucoma risk. Reading or typing on smartphones can also tax the eyes due to their small size. One study
found that text-based smartphone use can significantly raise eye pressure when using the device in low-light conditions for five minutes or more. So, try to avoid using smartphones in dimly lit areas. Also, remember to take periodic breaks and do eye exercises
when using digital screens for extended lengths of time.
Because glaucoma is a slowly progressive disease, it can be tempting to put it on the backburner and neglect the proper care of your eyes. But if you want to preserve your precious vision, it’s important to give your eyes the care they need every day.