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Disease

Neovascular Glaucoma

 

 

 

 

 

 

 

Definition: Neovascular glaucoma is an elevation of intraocular pressure (IOP) due to anterior synechia (adhesion between the iris and the cornea) and a fibrovascular membrane blocking the anterior chamber angle. This glaucoma develops slowly with new blood vessels growing originally at the pupil margin and then extending over the iris toward the angle. The new vessel growth is known as rubeosis irides. Once the vessels reach the anterior chamber angle, the fibrovasculature membrane that helps support the new vessels can block aqueous flow and may even close the angle by causing a peripheral anterior synechia.

Causes and Risk Factors: There are many diseases that have been associated with neovascular glaucoma. The vessel growth is started in response to hypoxia or a lack of oxygen. It is believed that the hypoxia signals are not from the iris, but are angiogenic factors from the retina that have diffused up to the iris, and is responsible for the new vascular growth which can lead to glaucoma. Some of the more common diseases that may cause this to occur are central retinal vein and artery occlusions, branch retinal artery and vein occlusions, diabetic retinopathy, chronic retinal detachment, carotid occlusive disease, and iridocyclitis.

Signs & Symptoms:

• may be asymptomatic
• chronically red, painful eye
• significant vision loss

Treatment: The treatment for neovascular glaucoma is to reduce the oxygen demand being made by the retina. This can be done using pan-retinal photocoagulation (PRP) to destroy the ischemic retina which lowers the demand for oxygen and will induce a regression of the new vasculature. If the peripheral anterior synechia has closed off a great portion of the angle, then filtering surgery may be required to lower the IOP.