What is Neovascular Glaucoma (NVG)?
Glaucoma is an eye disease leading to loss of retinal ganglion cells which can cause severe loss of visual function and also blindness. For more common forms of glaucoma, such as primary open angle glaucoma, the main issue in treatment is to lower the intraocular pressure, a major risk factor for this disease. Unfortunately, in neovascular glaucoma (NVG) this treatment is not as effective as for other types of glaucoma, which is based on the pathogenesis of neovascular glaucoma, a secondary type of glaucoma. As the name implicates, neovascular glaucoma is accompanied by new blood vessel formations in the anterior and also posterior segment of the eye.
Today’s therapeutic standards of care in NVG are invasive, often insufficient and involve laser or cryo-therapy to destroy the affected retina. For this reason, better treatments are in investigation.
Ischemic Central Retinal Vein Occlusion (iCRVO) is the main cause of NVG
The major cause of neovascular glaucoma is ischemic Central Retinal Vein Occlusion (iCRVO). NVG with underlying ischaemic CRVO typically develops after an average period of about 90 days, so it is often called “90 days-glaucoma”, but may also appear as early as two weeks or alternatively after a much longer period of time. The resulting reduction of oxygen supply of the retina leads to increased production of Vascular Endothelial Growth Factor (VEGF). This factor promotes the growth of new blood vessels, beginning often nearly as soon as the injury has occurred.
In general the vessels start to develop much earlier than they can be detected clinically and therefore can create damage before clinicians see a need for treatment. But treating these new vessels and accompanying fibrous tissue is the most urgent need in order to prevent the development of later stages of neovascular glaucoma, which is often accompanied by very high and difficult to control intraocular pressure, severe pain, blindness and eventually enucleation (removal) of the eye.
About the incidence of NVG
Neovascular glaucoma is a rare eye disease responsible for 3.9% of all glaucoma cases, with a prevalence of about 4/10,000 and affects about 300’000 people across Europe. It contributes disproportionally to blindness from all eye diseases. Today’s therapeutic standards of care are invasive, often insufficient and involve laser or cryo-therapy to destroy the affected retina. For this reason, better treatments are in investigation.