Checking For Healthy Eyes: 3 Types Of Tonometry Tests Used To Diagnose Glaucoma

25 October 2015
 Categories: , Blog


Glaucoma is one of the most misunderstood diseases. It can lead to detrimental and irreversible eye damage if it is left untreated. Unfortunately, over 3 million Americans have glaucoma, and more than half of them are unaware of it. Getting periodic eye examinations once every two years or once a year, depending on your age, is crucial for a proper diagnosis. Tonometry tests are most commonly used for diagnosing glaucoma, and basically measure the intraocular pressure within each eye. There are different types of tonometry tests that you can choose to take. This article will look at 3 different types, their unique traits and their advantages and disadvantages.

Goldmann Applanation Tonometry Tests

One of the easiest tonometry tests to perform is the Goldmann applanation tonometry test. This test involves gently pressing a probe against the cornea with the goal of flattening it. The amount of force that needs to be applied before the cornea is flattened is measured as the intraocular pressure of the eye. Each eye needs to be tested separately.

The main benefit of opting for the Goldmann applanation tonometry test is the cost. If you don't have insurance, this test is the least expensive option available due to the fact that it is easy and simple to perform. The accuracy of the reading will solely depend on the amount of experience that the doctor has; however, this test is generally hailed as the most accurate method available. Although beneficial in numerous ways, this test can be uncomfortable for the patient, which is why anesthetic eye drops are often administered to lessen any discomfort that may be experienced.

Non-Contact Tonometry Tests or Pneumotonometer Tests

Noncontact tonometry tests are also known as pneumotonometer tests. They rely on a special medical instrument that resembles an air piston to determine the intraocular pressure within the eye. During the test, a puff of air will be directed at an open eye, and the pressure exerted is measured. To make it simple, this test measures intraocular pressure using the same mechanisms as the Goldmann applanation tonometry test.

This test is normally recommended for children because it is easy to administer and does not cause any discomfort at all. it is also relatively cheap. However, non-contact tonometry tests cannot provide a definite diagnosis, and an eye doctor will usually perform other tests to confirm the diagnosis. This test is considered to be less accurate than the Goldmann applanation tonometry test.

Electronic Tonometry Tests

The electronic tonometry test involves using an instrument that resembles a pen. The tip of the instrument is pressed against the cornea of each eye and the intraocular pressure will be measured and shown via an electronic readout present on the device. This test differs from the Goldmann applanation test by how the pressure is read.

This testing technique is highly preferred by doctors who require a portability testing device. Since the device will come into physical contact with the cornea, anesthetic eye drops are required. In general, multiple readings will be needed for accuracy.

Glaucoma cannot be prevented, but it can be treated if it is diagnosed early. Unfortunately, damage caused by glaucoma is irreversible and any vision loss experienced cannot be restored. If you ever experience symptoms like seeing halos around lights, constant eye pain, vision loss or even tunnel vision, book an appointment with your eye doctor immediately to get checked out.