Neovascular Glaucoma

Neovascular glaucoma (NVG) is a secondary glaucoma characterized by new vessels on the iris and angle of the anterior chamber (AC). It is usually associated with a poor visual prognosis. The mechanism of anterior segment neovascularization is ischemia of the posterior segment of the eye resulting from several ophthalmic and systemic etiologies. The most common etiologies include proliferative diabetic retinopathy (PDR), central retinal vein occlusion (CRVO), and ocular ischemic syndrome (OIS).  In 1906, Coats described new vessels over the iris (rubeosis iridis) in a patient with CRVO. Due to the formation of new vessels in the anterior segment of the eye, the rise in intraocular pressure, and the connective tissue growth, the term NVG was coined by Weiss et al. Some other synonyms used for NVG are hemorrhagic glaucoma, thrombotic glaucoma, and congestive glaucoma.  NVG is usually refractory to treatments, and visual morbidity is significant for the patient. There are increasing numbers of NVG cases, probably due to the rise in the number of patients with diabetes and other non-communicable diseases, which are risk factors for retinovascular entities such as diabetic retinopathy, retinal vein occlusions, and ocular ischemic syndromes. Knowledge of the evaluation and management of NVG is crucial for all ophthalmologists.