In the treatment of open-angle glaucoma, your eye doctor will try to reduce the risk of damage to your optic nerve by keeping your eye pressure (intraocular pressure, or IOP) from rising above a certain level. That level of pressure is called your target pressure. By reducing the risk of optic nerve damage, maintaining the target pressure in your eyes may help slow the progression of the disease.

Tonometry is used to measure the pressure in the eyes. The target pressure is based on the degree of optic nerve damage, the amount of visual field loss and, to a lesser degree, the initial pressure in the eye and how widely it varies each time it is measured. The target pressure varies from person to person.

The target pressure may be lowered during treatment if there are signs that your glaucoma is getting worse.