Tonometry

Intraocular pressure (IOP) measurement; Glaucoma test; Goldmann applanation tonometry (GAT)

Tonometry is a test to measure the pressure inside your eyes. The test is used to screen for glaucoma.

Eye

The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle tunic layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.

How the Test is Performed

How to Prepare for the Test

How the Test will Feel

Why the Test is Performed

Normal Results

What Abnormal Results Mean

Risks