If glaucoma is diagnosed, these tests should continue to be performed at regular intervals to monitor the patient's condition and the effectiveness of treatment. Intraocular Pressure Intraocular pressure is measured by tonometry. This is a quick and painless technique that determines if the pressure within the eye is elevated to higher than normal levels. Not everyone with elevated pressure will develop glaucoma. However, the higher the pressure, the greater the chance that a person has glaucoma or will develop glaucoma in the future.
Some people can develop glaucoma even when their pressure is in the normal range.
Because intraocular pressure fluctuates throughout the day, pressure may have to be measured several times. An ophthalmologist looks at the angle of the eye using a technique called gonioscopy. In gonioscopy, a special lens is used to examine the drainage channels in the angle of the eye. An anesthetic is used, making the technique painless. This helps the ophthalmologist determine whether a person is at risk for developing acute angle-closure glaucoma.