What is ocular hypertension?
Ocular hypertension is an eye condition where the pressure inside the eye—or intraocular pressure—is higher than it should be. The pressure comes from a fluid called aqueous humor. It fills the chamber within the front of the eye between the cornea—or outer shell of the eye—and the lens, which divides the front and back of the eye. The eye is constantly making aqueous humor and draining it to nourish its tissues. The intraocular pressure can become too high if there is too much aqueous humor or if it can’t drain properly.
Ocular hypertension is not the same thing as glaucoma. The difference between ocular hypertension vs. glaucoma is damage to the optic nerve. In glaucoma, the optic nerve is not healthy, leading to vision problems and even blindness.
Ocular hypertension, on the other hand, is a major risk factor for developing glaucoma. High intraocular pressure is one of the main causes of optic nerve damage and glaucoma. However, you can get glaucoma without having ocular hypertension. And not everyone with ocular hypertension will go on to develop glaucoma. Regular monitoring is necessary for people with ocular hypertension. If signs of damage show up, early intervention can help preserve your vision.
Typically, ocular hypertension causes no symptoms, but doctors can find it on a routine eye exam by measuring it with a tonometer. To diagnose ocular hypertension, the results have to be elevated in one or both eyes on two separate occasions.
Your risk of having ocular hypertension is higher if you are African American, over 40, or have a family history of it or of glaucoma. About 4.5% of Americans who are 40 have ocular hypertension. This rate increases to about 7.7% at age 75.
Unfortunately, ocular hypertension isn’t curable, but it is treatable. If your eye doctor decides treatment is necessary, it may simply involve eye drops to lower the pressure inside the eye. In some cases, doctors recommend laser therapy or surgery to relieve pressure. Treatment helps decrease the risk of developing glaucoma and vision loss. However, it doesn’t completely eliminate it. You will still need regular monitoring and eye exams.
Sometimes, very high intraocular pressure can cause pain when you move your eyes or touch them. Seek prompt medical care if you experience this.
What are the symptoms of ocular hypertension?
Ocular hypertension doesn’t have any signs or symptoms in most cases. This means you can have increased intraocular pressure and not know it, and this puts your vision at risk if you go on to develop glaucoma. So, it’s important to follow guidelines for regular eye care. During a complete eye exam, doctors measure intraocular pressure with a tool called a tonometer. There are a few different versions of this tool. A common one involves using a puff of air to briefly flatten the cornea. The amount of flattening tells your doctor about the pressure inside your eye.
You should have a baseline eye exam in your 20s and see your eye doctor twice in your 30s. Once you reach age 40, you should have a complete eye exam and your doctor will use the results to tell you how often you need to return. If you have a family history of ocular hypertension or glaucoma, these guidelines may change. Talk with your eye doctor to find out how often you should have exams.
In some cases, people can experience symptoms when the intraocular pressure is very high. Typically, this includes pain with eye movement or with touch. See your eye doctor as soon as possible if you have these symptoms.
What causes ocular hypertension?
Eyeballs aren’t empty organs. They contain two types of fluid—vitreous humor that fills the eye from the lens back to the retina and aqueous humor that fills the area in front of the lens. Normally, the eye continually makes new aqueous humor and drains away the old fluid. Ocular hypertension occurs when too much aqueous humor builds up in the front part of the eye. This can be the result of an overproduction of the fluid or inadequate drainage of it. The reason either of these problems happen is unclear.
What are the risk factors for ocular hypertension?
A number of factors increase the risk of developing ocular hypertension. However, not all people with risk factors will develop ocular hypertension. Risk factors include:
- African American or Hispanic heritage
- Age 40 years or older
- Eye injuries, surgery, and conditions, such as pigment dispersion syndrome and severe nearsightedness
- Family history of ocular hypertension or glaucoma
- Long-term use of corticosteroid medications
Reducing your risk of ocular hypertension
Many of the risk factors for ocular hypertension are beyond your control. You can’t change your genetics. However, if you have medical conditions that increase your risk, there are steps you can take to help reduce your risk. Controlling your blood sugar, blood pressure, and other eye conditions may prevent ocular hypertension.
If you have any risk factors for ocular hypertension, see your eye doctor on a regular basis. The only way to know if you have high intraocular pressure is through a complete eye exam that includes tonometry.
How is ocular hypertension treated?
Whether or not ocular hypertension requires treatment depends on your risk of developing glaucoma. For low-risk people, it may be appropriate to simply monitor eye pressure and optic nerve health on a regular basis. In people who are high-risk, treating ocular hypertension can reduce the occurrence of glaucoma by more than 50%.
The treatment goal is to restore intraocular pressure back within the normal range. This typically involves using ocular hypertension medication in the form of eye drops including:
- Alpha agonists, such as apraclonidine (Iopidine) and brimonidine (Alphagan-P)
- Beta blockers, such as betaxolol (Betoptic), levobunolol (Betagan), and timolol (Timoptic)
- Carbonic anhydrase inhibitors, such as brinzolamide (Azopt) and dorzolamide (Trusopt)
- Prostaglandin agonists, such as bimatoprost (Lumigan), latanoprost (Xalatan), and travoprost (Travatan)
- Rho kinase/norepinephrine transporter inhibitors, such as netarsudil (Rhopressa)
There are also several combination products available that use drugs from two different classes. In a few cases, doctors recommend using laser therapy or surgery to reduce intraocular eye pressure.
What are the potential complications of ocular hypertension?
The main complication of ocular hypertension is glaucoma—or damage to the optic nerve. Glaucoma can cause vision problems and is a leading cause of blindness in older people. However, not everyone with ocular hypertension will go on to develop glaucoma. If you have ocular hypertension, risk factors that make it more likely that you will develop glaucoma include:
- Bleeding at the optic nerve head
- Family history of glaucoma
- Higher intraocular pressure
- Lower ocular perfusion pressure
- Older age
- Thinner central cornea
Several of these risk factors can only be determined on a complete eye exam. Talk with your doctor about your risk category for glaucoma to understand your individual likelihood of developing it.
Remember, treating ocular hypertension reduces the risk of glaucoma, but doesn’t eliminate it. It’s important to continue with regular eye exams throughout your life.