Tonometry is a diagnostic test that measures the pressure inside your eye, which is called intraocular pressure (IOP). This measurement can help your doctor determine whether or not you may be at risk of glaucoma.
Glaucoma is a serious eye disease that can eventually lead to vision loss if untreated. In most cases of glaucoma, the fluid that normally bathes and nourishes the eye drains too slowly, causing pressure to build up.
Without treatment, the increased pressure can eventually harm your optic nerve and cause vision loss. According to the American Academy of Ophthalmology (AAO), glaucoma is one of the leading causes of blindness in adults over the age of 60.
The changes caused by glaucoma are often painless and can progress for years without you noticing. A tonometry test is critical for detecting the changes early.
If your test results come back abnormal, your eye doctor will recommend additional testing to confirm that you have the disease.
Tonometers measure the internal pressure of the eye and tonometry is one of the principal tests for glaucoma, but until relatively recently their use in the eye examination was far from routine. A patient's intraocular pressure (IOP) should normally be 15. Any reading in the region of 21 or 22 signifies an increased likelihood that the patient will go on to develop glaucoma.