The Eye Pressure Test: What Tonometry Tells You About Glaucoma Risk
Tonometry is the test that measures the pressure inside your eye. It's a routine part of a comprehensive eye exam at Uptown Eye Boutique in Johns Creek, and it's one of the main ways Dr. Brian Schultz screens for glaucoma risk.
Why eye pressure matters
Your eye is filled with fluid that is constantly produced and drained. If the fluid doesn't drain well, pressure inside the eye can rise. Over time, high pressure can damage the optic nerve, the cable that carries visual information from your eye to your brain. That damage is called glaucoma, and it can't be reversed.
What the numbers mean
Eye pressure is measured in millimeters of mercury (mmHg). A range of roughly 10 to 21 mmHg is commonly considered normal, but there's no single number that is safe for everyone:
Some people have pressure above that range for years without developing glaucoma
Others develop glaucoma even though their pressure stays in the normal range
Corneal thickness can make a pressure reading look higher or lower than it really is
That is why a pressure reading on its own doesn't diagnose or rule out glaucoma.
How the test is done
There are a few ways to measure eye pressure. Some instruments use a gentle puff of air and never touch the eye. Others briefly touch the surface of the eye after numbing drops are put in. Either way, the measurement takes only a moment and is not painful.
Why pressure is only part of the picture
Because pressure alone can be misleading, Dr. Schultz looks at it alongside other information:
An OCT scan measures the nerve fibers around the optic nerve
A visual field test checks for early loss of side vision
Retinal imaging records the appearance of the optic nerve
Your age, family history and other health conditions round out your risk
Who is at higher risk for glaucoma?
Glaucoma risk rises with age. It is also more common in people with a family history of glaucoma, people of African, Hispanic or Asian descent, people with diabetes or high myopia, and people who have used steroid medications long-term. If any of these apply to you, regular exams are especially important. Learn more about our glaucoma testing in Johns Creek.
Frequently asked questions
Does the eye pressure test hurt?
No. The air-puff version can be startling but doesn't hurt, and the contact version uses numbing drops first.
My pressure was high. Do I have glaucoma?
Not necessarily. High pressure is a risk factor, not a diagnosis. Dr. Schultz will use other tests to see whether there is any damage to the optic nerve.
Can eye pressure change during the day?
Yes, it naturally varies. Repeat readings over time give a more reliable picture than a single measurement.
Uptown Eye Boutique is open Monday through Saturday in Johns Creek, GA. Comprehensive eye exams are provided by Dr. Brian Schultz, OD.
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