In this condition, the drainage canals in the eye are blocked by the iris. This leads to a pressure build up that can damage the optic nerve. The iris comes forward, away from its normal position, and closes off the drainage canal. A procedure called laser peripheral iridotomy (LPI) is performed to treat angle closure glaucoma. It creates a hole in the iris’s outer edge, which then leads to opening of the blocked angle. By widening the angle and removing the obstruction, improve outflow is established through the LPI.