Refractory glaucoma is defined as any glaucoma with intraocular pressure (IOP) inadequately controlled with maximally tolerated medical therapy or laser trabeculoplasty. Pressure-lowering efforts are then directed toward incisional surgical interventions or cyclodestructive procedures. The situation of angle-closure glaucoma unresponsive to standard therapy is also discussed. This chapter covers the neovascular glaucoma (NVG), glaucoma occurring after retinal detachment surgery, glaucoma occurring after penetrating keratoplasty, uveitic glaucoma, malignant glaucoma, angle-closure glaucoma not responsive to laser iridotomy, procedures, tube shunts, postoperative care, cyclodestructive procedures, cyclophotocoagulation, cyclocryotherapy, and peripheral iridoplasty. Neovascular glaucoma (NVG) occurs when an abnormal fibrovascular membrane grows into the drainage angle and obstructs aqueous outflow. Malignant glaucoma, also referred to as aqueous misdirection syndrome, is an uncommon condition that is classically described following incisional surgery for angle closure glaucoma.