Understanding the Perimetry Test for Diagnosing Glaucoma
There are a few ways your eye care professional can determine if you are showing symptoms of developing glaucoma. One of the most common things your doctor will perform is a perimetry test, which measures all the areas of your eyesight, especially your peripheral vision.
To perform the test, your eye care professional will have you look inside a bowl-shaped device, the perimeter, at stare straight ahead. While staring, lights will begin to flash in different parts of the “bowl,” with you prompted to press a button every time you see a flash. A computer records when the light appeared and when you saw the flash.
The results of the test help determine if there are areas of your vision where you did not see the flashes of light. These areas are where vision has been lost. Many times, loss of peripheral vision is an early sign of glaucoma.
According to eye expert, Dr. Robert McCulloch, Vision loss happens first at the outer edge of your sight, farthest from the center of the eye, most often on the nose side. The amount of peripheral vision that is lost is linked to the amount of optic nerve damage from glaucoma. As glaucoma worsens, larger areas of vision loss are picked up by the perimetry test.
Even if you have been diagnosed with glaucoma, the perimetry test is often regularly used by your eye doctor to see if your current treatment for the eye disease is preventing further vision loss.
The test, which checks both eyes, is typically done in under an hour. If you feel like you’re are noticing some peripheral vision loss, contact your eye care professional to schedule a perimetry test.