In the treatment of glaucoma, your eye doctor will try to keep your eye pressure (intraocular pressure, or IOP) from rising above a certain level. That level of pressure is called your target pressure. Maintaining the target pressure in your eyes can reduce the risk of optic nerve damage. It may help slow the progression of the disease.
A tonometry test is used to measure the pressure in the eyes. The target pressure is based on the degree of optic nerve damage and the amount of visual field loss. It is also based on the initial pressure in the eye and how widely it varies each time it is measured. The target pressure varies from person to person. It is usually about 20% to 30% less than the highest IOP you've had.
When the tonometry measurement is above target pressure, your doctor will consider making changes to your treatment. These changes may include starting medicine, changing your medicine, or talking with you about options for surgery.
Author: Healthwise Staff Medical Review: Adam Husney MD - Family Medicine E. Gregory Thompson MD - Internal Medicine Christopher J. Rudnisky MD, MPH, FRCSC - Ophthalmology