Tonometry is a test to measure the pressure inside your eyes. The test is used to screen for glaucoma.
There are several methods of testing for glaucoma.
The most accurate method measures the force needed to flatten a certain area of the cornea.
A slightly different method uses a handheld device similar in shape to a pencil. Again, you are given numbing eye drops to prevent any discomfort. The device touches the outside of the eye and instantly records eye pressure.
The last method is the noncontact method (air puff). In this method, your chin rests on a padded stand.
Remove contact lenses before the examination. The dye can permanently stain contact lenses.
Inform the health care provider if you have corneal ulcers and infections, an eye infection, if you are taking any drugs, or if you have a history of glaucoma in your family.
If numbing eye drops were used, you should not have any pain. In the noncontact method, you may feel mild pressure on your eye.
Tonometry is a test to measure the pressure inside your eyes. The test is used to screen for glaucoma.
People over age 40, especially African Americans, have the the highest risk for developing glaucoma. Regular eye exams can help detect glaucoma early. If it is detected early, glaucoma can be treated before too much damage is done.
The test may also be done before and after eye surgery.
A normal result means your eye pressure is within the normal range. The normal eye pressure range is 10 - 21 mmHg.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
Abnormal results may be due to:
If the applanation method is used, there is a small chance the cornea may be scratched (corneal abrasion). This will normally heal itself within a few days.
Intraocular pressure (IOP) measurement; Glaucoma test; Applanation
Updated by: David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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