URMC / Flaum Eye Institute / Angle Surgery / Overview Overview Since 1856 – when von Graef demonstrated iridectomy as an effective treatment for acute glaucoma – there have been numerous surgical advances aimed at increasing aqueous outflow. Many of the techniques used to treat open angle glaucoma were introduced in the 1960’s and are still used today. Procedures of note include: Trabeculectomy (filtering procedures) Valved and non-valved drainage devices Iridotomy Laser Trabeculoplasty All of these surgeries have advantages as well as liabilities. They are generally performed only when the ophthalmologist determines that pharmaceutical options and aqueous limiting laser procedures are no longer effective, or pose undue hardships on patients. 2005 began the introduction of a continuing stream of technological advances to improve aqueous outflow that are less aggressive and reduce the risk of complication. Minimally Invasive Glaucoma Surgery (MIGS) is an option that may delay—or eliminate altogether—the need for trabeculectomy and other procedures. Routinely combined with cataract removal, MIGS is shown to be effective at lowering pressure, minimizing complications and increasing patient comfort. MIGS and Intraoperative Gonioscopy With the increasing popularity of MIGS among anterior segment surgeons, knowledge of intra-operative gonioscopy is crucial. Many of the devices/technologies employed are minuscule, and their success at lowering pressure is highly dependent upon accurate deployment/placement. Therefore, visualizing the anterior chamber angle during surgery is vital. We hope that the techniques and technologies presented throughout will improve your surgical confidence and competence, thereby allowing you to offer MIGS to patients, expand your current MIGS practice or develop your technique as a resident or fellow.