Routine eye exams contain many different measurements and aspects. Tonometry is just one of those measurements and is an important part of your eye exam as it can alert your doctor to potential problems with your eyes.

What is tonometry?

Tonometry refers to the measurement of the intraocular pressure of the eye in millimeters of mercury.  There are several different instruments that can be used to determine Tonometry, but the gold standard for measuring intraocular pressures is still considered to be the use of applanation tonometry by a Goldman Tonometer.

How does intraocular pressure affect your vision?

Traditionally, the normal pressure ranges for your eyes are considered to be between 10 and 21 mmHG.  Anything above 21 mmHG is classified as Ocular Hypertension. When Ocular Hypertension leads to nerve damage, it is called glaucoma.

As intraocular pressure rises, the risk of nerve damage and retinal nerve fiber loss increases.  This results in the loss of peripheral vision at first, but advanced stages can involve central vision as well.

It is important to note, however, that nerve fiber loss can occur even in the presence of “normal” intraocular pressure.  In this instance, it is called normal tension glaucoma.

What happens if your doctor determines you’re at risk for glaucoma?

If it is determined that you are at risk for glaucoma, a follow-up appointment will be established.  At the follow-up, we will use special instruments to measure your peripheral vision and determine the amount of retinal nerve fiber loss.

At Clarke EyeCare Center, you can be assured that we are using the most advanced technology available in assessing your risk.