Ocular Hypertension

What is ocular hypertension?

Ocular hypertension refers to high intraocular pressure (IOP), or high pressure inside your eye. Fluid drainage failure causes the high pressure.

Your eyes constantly make a clear fluid called aqueous humor that flows in front of your eye and then drains out. Normally, an equal amount goes in and out. If the fluid doesn’t leave your eye when it should, your IOP increases.

Normal eye pressure is 11 to 21 millimeters of mercury (written as mmHg). This is the same type of measurement used in taking your blood pressure. If your ocular pressure is higher than 21 mmHg in one or both eyes at two or more visits to your eye care specialist, then you may have ocular hypertension.

Bilateral ocular hypertension happens in both eyes. Unilateral ocular hypertension means that pressure is high in only one eye.

What is the difference between ocular hypertension and glaucoma?

Ocular hypertension can cause glaucoma. Glaucoma happens when high IOP damages the optic nerve. These nerves in both eyes connect directly to your brain and transmit electrical signals that your brain turns into images.

If you have glaucoma that’s not treated, you can lose your vision.

How common is ocular hypertension?

An estimated 3 million to 6 million people in the U.S. have ocular hypertension, which puts them at risk for developing glaucoma.

What are the risk factors for ocular hypertension?

A risk factor is some particular thing that increases the chance that you’ll develop a disease. Some risk factors can’t be changed, like your age, your ethnicity or having another type of medical condition. Risk factors for ocular hypertension, and for developing glaucoma, include having other conditions, such as:

• Both high blood pressure (hypertension) and low blood pressure (hypotension).
• Diabetes.
• Extreme nearsightedness (myopia).
• A thinner central cornea (the “window” of your eye which is clear and provides protection).
• Bleeding at the optic nerve head.
• Pigment dispersion syndrome: This condition means that pigment from your iris flakes off. The iris is the colored part of your eye. These particles can block your drainage system.
• Pseudoexfoliation syndrome (PXF): In this condition, flakes of protein can build up in your organs, including your eyes.

Other risk factors for ocular hypertension include:

• Being over 40 years of age.
• Having a family history of glaucoma or ocular hypertension.
• Being Black or Hispanic.
• Taking steroid medications for a long time.
• Having had previous eye injuries or eye surgeries.

What are the signs and symptoms of ocular hypertension?

The tricky thing about ocular hypertension is that it generally doesn’t cause symptoms. This is why regular eye exams are so important. Your healthcare provider can tell if the pressure inside your eye is high when they do their testing.

In some cases, you may feel eye pain with movement of your eyes or touching your eyes.

Even though some eye problems may create headaches or dizziness, this doesn’t usually happen with ocular hypertension.

What causes ocular hypertension?

Causes of ocular hypertension include making too much fluid (aqueous humor) or having a blockage or other problem with your eye’s drainage system, called the anterior chamber angle. The drainage angle is near the front of your eye, located between the iris and the cornea.

If the drainage angle is blocked, it causes fluid and pressure to build up. Causes of this build-up can include:

• The drainage angle is closed.
• The anterior chamber is open, but not draining properly.
• Pigment or protein flakes are blocking the drainage angle.
• Eye cancer is blocking the angle.
• Eye damage has happened earlier.

Can stress cause ocular hypertension?

Recent studies have indicated that stress can increase intraocular hypertension.

How is ocular hypertension diagnosed?

Your eye doctor will begin by giving you a thorough eye exam. If they suspect you might have ocular hypertension, they may also do these tests:

• Gonioscopy: This test checks whether your eye’s drainage system (anterior chamber angle) is working properly. It uses a special lens and a type of microscope called a slit lamp.
• Pachymetry: This test measures cornea thickness.
• Tonometry: This test measures inner eye pressure.
• Visual field test: This is a way to check your field of vision.
• Optical coherence tomography: This test checks the health of the optic nerve tissue.

How is ocular hypertension treated?

Sometimes, you and your provider may decide to monitor the situation closely at scheduled eye appointments. Your provider may prescribe eye drops to reduce the pressure in your eyes. They’ll also continue to monitor your intraocular pressure at regular eye exam appointments.

Medications to lower pressure in your eyes include:

• Prostaglandins: Use these eye drops once a day to increase the amount of fluid leaving your eye.
• Beta-blockers: You may be told to use this type of eye drop once or twice a day to decrease the amount of fluid you produce.
• Alpha-adrenergic agonists: You might use this type of medication two or three times per day to reduce fluid output and increase fluid throughput.
• Carbonic anhydrase inhibitors: You might use this type of medication two or three times per day to reduce fluid output.
• Rho kinase inhibitor: This product lowers the production of fluid when used once a day.
• Miotic or cholinergic agents: You must use these products four times per day. Providers had prescribed this type of product more often in previous years, but they don’t prescribe them as often now. The agents increase the outflow of fluid from your eyes.

As with all medications, these products may have unwanted side effects, like redness or irritation of the eyes. In some cases, if you don’t respond to the prescribed medications, you might need surgery to reduce the pressure in your eyes. One type of procedure is laser trabeculoplasty, which uses a laser to open blockages.

How can I reduce my risk of developing ocular hypertension?

Most of the risk factors for ocular hypertension aren’t things you can modify. However, you can do your best to keep your eyes healthy. These suggestions include tips for your overall health and your eye health.

Eye exams

It’s important to make and keep appointments for regular eye examinations. Finding problems early is best.

Smoking

Don’t smoke. Smoking is bad for your eyes. Talk to your provider about getting help to quit smoking.

Eye health

You can protect your eyes by:

• Wearing sunglasses.
• Wearing protective eye gear when you work or participate in contact sports.
• Knowing about family history of eye diseases like glaucoma or macular degeneration.
• Rest your eyes when you’re working on screens. Follow the 20-20-20 rule. Every 20 minutes, look at something 20 feet away for 20 seconds.
• Take care to avoid eye infections, especially if you wear contact lenses.

Overall health

You can help protect your eyes by keeping yourself healthy. Tips for this include:

• Eat a healthy diet. Include dark green leafy vegetables like collard greens, kale and spinach. Add fish that provide omega-3 fatty acids like halibut, salmon and tuna.
• Exercise. Activity is good for you. It can help protect against other health issues.
• Keep your blood pressure levels, your cholesterol levels and your blood sugar levels stable.
• Take measures to relieve your stress, like Reiki, yoga or meditation. (Exercise is a good stress reliever, too.)

What can I expect if I have ocular hypertension?

You can’t cure ocular hypertension, but your provider can treat and monitor the condition.

People who have ocular hypertension may be at a higher risk for developing glaucoma, but not everyone who has ocular hypertension will automatically develop glaucoma.

When should I see a healthcare provider about ocular hypertension?

You should see your provider as often as they recommend. If you have unusual eye discomfort or pain, or discomfort that doesn’t go away, you should always contact your eye care provider. You should also contact them if you have new or worsening symptoms that involve your eyes.

A note from Cleveland Clinic

It’s important for everyone to have regular eye exams, but this is very true if you have ocular hypertension. It’s also important to use the medications that your provider prescribes for you in the way that your provider recommends. With proper care, you can stop ocular hypertension from progressing to optic nerve damage and vision loss.