Intraocular pressure (IOP), known as eye pressure, is the force exerted by the fluid inside your eyes. This pressure is crucial for maintaining your eyes' overall health and proper function.

Your eyes contain two types of fluid: vitreous humor and aqueous humor. The vitreous humor is a thick, gel-like substance that fills the chamber at the back of your eye, while the aqueous humor is a thinner, water-like fluid that occupies the front part of your eye, between the cornea and iris.

Your body naturally regulates intraocular pressure. As new aqueous humor is produced, an equivalent amount of the older fluid exits the eye through the drainage angle, where the iris meets the sclera.

When intraocular pressure is high, it is known as ocular hypertension. If left untreated, this increased pressure can damage the optic nerve, potentially leading to glaucoma and permanent vision loss.

How is Intraocular Pressure Measured?

During an eye exam, an optometrist uses a test called tonometry to measure eye pressure. Tonometry assesses the pressure inside your eye by flattening the cornea (the clear front part of your eye). The most common form of this test is non-contact or air puff tonometry. In this method, a machine releases a brief puff of air against your eye and measures the cornea's movement in response.

A normal intraocular pressure ranges between 10 mmHg and 21 mmHg.

In a healthy eye, aqueous humor, or fluid, continuously circulates through the eye. This eye fluid plays several crucial roles, including:

• Lubrication: Keeping the muscles and fibers of the focusing lens lubricated.
• Nourishment: Providing nutrients and oxygen to the back of the cornea.
• Waste Removal: Removing waste products from the cornea.
• Shape Maintenance: Maintaining the shape of the cornea.

As new fluid is made, the old fluid drains out through the eye’s front angle and leaves through the trabecular meshwork and Schlemm’s canal. To maintain normal intraocular pressure (IOP), this drainage system must remain clear and functional. If a problem occurs and the fluid cannot drain efficiently, it can accumulate and cause an increase in eye pressure.

What Happens When Eye Pressure Remains High?

Increased eye pressure can result from various factors. A key cause is when the fluid in the eye doesn’t drain properly. However, other issues can also contribute to fluid buildup. Certain changes within the eye can impact intraocular pressure more rapidly than the body can regulate, such as excessive production of aqueous humor, blockages in the drainage system, or trauma and injuries to the eye.

People with high intraocular pressure are at a higher risk of developing glaucoma, a condition that damages the optic nerve due to the buildup of fluid in the front part of the eye, increasing pressure and harming the optic nerve.

It's important to understand that changes in eye pressure typically do not cause pain and can go unnoticed for years, gradually leading to vision loss.

This makes a tonometry test essential for detecting early signs of increased eye pressure or other ocular issues that may raise your risk of glaucoma. Early detection significantly increases your chances of preventing vision loss and preserving your remaining vision.

At ASG Eye Hospital, we prioritize your eye health with comprehensive eye exams that include crucial intraocular pressure measurements. Regular check-ups can help detect early signs of increased eye pressure and potential risks for conditions like glaucoma.