A New Angle on Angle Surgery

G laucoma surgery has long relied on ab externo techniques such as augmented trabeculectomy and tube-shunt procedures. While these have excellent potential to lower intraocular pressure (IOP), they are associated with risks, including hypotony, and are therefore conventionally reserved for those with advanced glaucoma or at high risk of visual loss. Traditional filtering surgery attempts to bypass the eye’s physiological outflow pathway, however new minimally invasive glaucoma surgery (MIGS) procedures have recently been introduced that focus on the angle structures as a target for improving aqueous outflow. There are a growing number of ab interno MIGS procedures that utilise the natural drainage pathways of the eye in the management of glaucoma. This article examines the progress so far and describes how the angle has become a viable target for glaucoma surgery.