Problems with circulation of the eye affect its blood flow. Circulatory problems occur more commonly in people with diabetes mellitus and atherosclerosis. When the eye is starved of blood, it calls out for more nutrients and oxygen. In response to this call, new blood vessels sometimes grow inside the eye. This process of new blood vessel growth is called neovascularization. The new blood vessels may grow in places that are undesirable. One of the common locations for neovascularization is in the anterior chamber angle where they may cause scar formation that blocks outflow of fluid through the eye’s drainage apparatus. This leads to high intraocular pressure and optic nerve damage from glaucoma. This type of secondary glaucoma is called neovascular glaucoma.