Gonioscopy is used to visualize the anterior chamber angle of the eye, whichis the front part of the eye between the cornea and the iris. This structure cannot be seen unless a special lens, called a gonioscopy lens, is placed on the eye. The doctor then uses the mirrors in the gonioscopy lens to assess the health of this portion of the eye.
Gonioscopy is most often done if glaucoma is suspected. Before a diagnosis of glaucoma can be made, gonioscopy is done to determine which type of glaucoma is present. Glaucoma is a group of eye disorders in which a specific pattern of damage occurs to the optic nerve, resulting in loss of eyesight. Gonioscopy is done to determine whether the area in the eye where fluid drains out of the eye (called the anterior chamber angle) is damaged, blocked, or clogged. It is often done as part of a complete glaucoma exam. It may also be done during a routine eye exam, depending on your age and whether you are at high risk for developing glaucoma.