Neovascular Glaucoma.

Neovascular glaucoma (NVG) is a secondary ocular pathological condition resulting from a myriad of ocular and systemic conditions with retinal ischemia as a mediator in over 95% of cases. NVG is caused by the growth of a fibrovascular membrane secondary to a local angiogenic stimulus over the trabecular meshwork obstructing aqueous outflow. This results in an initial secondary open-angle glaucoma stage that may be amenable to intraocular pressure (IOP)-lowering medications and modulation of the underlying ischemic process, often in combination with panretinal photocoagulation and adjunctive use of vascular endothelial growth factor inhibitors. In the more advanced stages of neovascularization, connective tissue myofibroblasts associated with new vessel growth contract causing progressive synechial closure of the anterior-chamber angle. Elevation of IOP, once significant secondary angle closure is established, tends to be refractory to topical and oral IOP-lowering medications and often requires glaucoma surgical interventions.