The Express Shunt is a very small device (the size of a rice grain) that is placed in a patient’s eye when they have uncontrolled glaucoma. It is done to reduce a patient’s intraocular pressure to prevent further damage to their optic nerve and subsequently vision loss. It is placed inside of the eye in the area where normal eye fluid drains and provides an alternative route for fluid to exit the eye. When the fluid leaves the eye it enters a space below the layer of the eye called the conjunctiva and creates a small pocket where it slowly gets absorbed by the blood vessels nearby. This is an outpatient procedure with a slightly improved safety profile compared to traditional trabeculectomy surgery.