Gonioscopy is a procedure that is used to evaluate the eye’s internal drainage system. The drainage system of the eye is the location where the fluid inside the eye (aqueous humor) empties into the venous system. If it is not properly drained, the intraocular pressure could rise beyond normal and cause damage to the optic nerve. This results in glaucoma, the second leading cause of blindness in the world. This drainage system cannot be seen with the naked eye. Your doctor will place a special lens over your eye to see and evaluate this system.
Your head of will be positioned in a slit lamp (the special microscope used to look at the eyes). After the eyes are numbed with drops, the special lens will be placed directly on your eye’s surface as a beam of light is used to illuminate it. You may feel that there is something on your eye, but you shouldn’t feel any pain.
Gonioscopy is therefore used to monitor how well this fluid is drained, and evaluate the condition of blood vessels in your eye’s drainage system. It is essential in the diagnosis and management of intraocular pressure and glaucoma.