Ocular hypertension occurs when the pressure in the eye (known as intraocular pressure) is above the range considered normal (often defined as above 21 mm Hg). It is distinguished from glaucoma, a more serious eye condition, in that there are no detectable changes in vision, no evidence of visual field loss, and no damage to the optic nerve. Patients diagnosed with ocular hypertension have an increased risk of developing glaucoma.
What Causes Ocular Hypertension?
Ocular hypertension is the result of poor drainage of the aqueous humor (a fluid inside the eye). Essentially, this means that too much fluid enters the eye without being drained, causing high amounts of pressure to build up.
An injury to the eye, certain diseases and some medications may raise eye pressure. Your risk of developing ocular hypertension increases if you have a family history of ocular hypertension or glaucoma, have diabetes, are over the age of 40, are African American or are very near-sighted.
How Do You Know You Have Ocular Hypertension?
You can't tell by yourself that you have ocular hypertension, because there are no outward signs such as eye pain or red eyes. During a comprehensive eye exam, your eye care practitioner will measure your IOP and compare it with normal levels.
An eye pressure reading of 21 mmHg (millimeters of mercury) or higher generally signifies ocular hypertension.
If you picture your eye as a globe inflated by pressure, you can better understand why ocular hypertension should be monitored. Pressure that is too high or that continues to increase exerts a force within your eye's interior that can damage the eye's delicate optic nerve, causing glaucoma.
Treatment for Ocular Hypertension
If your eye doctor discovers you have ocular hypertension, he or she might prescribe eye drops to reduce your eye pressure.
Because these medications can have side effects, some eye doctors choose to monitor your IOP and take action only if you show other signs of developing glaucoma.
In some cases (or if eye drops are ineffective in reducing your IOP), your eye doctor might recommend other glaucoma treatment measures, including glaucoma surgery, to treat high eye pressure.
At a minimum, because of the increased risk for glaucoma with ocular hypertension, you should have your IOP measured at recommended intervals to monitor the condition.
Next Steps Follow-up
Depending on the amount of optic nerve damage and the level of intraocular pressure control, people with ocular hypertension may need to be seen from every 2 months to yearly, even sooner if the pressures are not being adequately controlled.
Glaucoma should still be a concern in people who have elevated intraocular pressure with normal-looking optic nerves and normal visual field testing results or in people who have normal intraocular pressure with suspicious-looking optic nerves and visual field testing results. These people should be observed closely because they are at an increased risk for glaucoma.
Ocular hypertension cannot be prevented, but through regular eye examinations with an ophthalmologist, its progression to glaucoma can be prevented.
The prognosis is very good for people with ocular hypertension.
- With careful follow-up care and compliance with medical treatment, most people with ocular hypertension do not progress to primary open-angle glaucoma, and they retain good vision throughout their lifetime.
- With poor control of elevated intraocular pressure, continuing changes to the optic nerve and visual field that could lead to glaucoma might occur.