Neovascular glaucoma (NVG) is a severe form of secondary glaucoma that occurs when the angle of the eye (where the iris and the cornea meet) is obstructed by the formation of new blood vessels. The area between the iris and cornea is referred to as trabecular meshwork and allows eye fluid known as aqueous fluid to flow out of the eye. 

When patients develop NVG, new vessels form in these areas, and eye fluid is not able to leave as needed. This leads to elevated intraocular pressure (IOP) since the fluid in the eye cannot access the drainage system. The eye becomes red and painful, and your vision gets compromised. 

The condition can occur in people with diabetic eye disease, in which a chemical, called vascular endothelial growth factor (VEGF), is released and creates more blood vessels. When the chemical migrates to the front of the eye, it can lead to the formation and blockage of the drainage system.

Known risk factors to aid in prevention

Controlling blood pressure and diabetes is vital for prevention. For diabetics especially, a key prevention measure is a yearly dilated exam—and even more frequently if they have a mild form of diabetic retinopathy. For anyone 65 years of age or older, a comprehensive eye exam every one to two years is suggested.

It’s important to first look for the symptoms of a retinal vein blockage or diabetic eye disease, which might include vision loss. These are the eye conditions that can lead to the deterioration of the drainage system (neovascular glaucoma.)

Risk factors for these retinal diseases include:

• Age
• High blood pressure
• Diabetes
• Heart disease
• High IOP

Symptoms to look out for

These diseases are often first discovered when patients begin to experience vision loss and seek care or during a routine annual eye exam. In addition to vision loss, symptoms of neovascular glaucoma can include eye pain and redness. It’s important to note that in the early stages of the disease, it’s possible to be asymptomatic.

How NVG is treated

Treating the underlying cause of NVG is key. To prevent and treat damage, your care team may include the collaboration of several specialists, such as a glaucoma and retina specialist or a comprehensive ophthalmologist.

Once treating the primary system cause, such as diabetic retinopathy, doctors may treat the symptoms with a retinal laser to decrease the retina’s production of VEGF, as well as injections of anti-VEGF medications into the eye to eradicate abnormal blood vessels causing an obstruction.

They will also lower IOP through medications (eye drops), laser, and/or surgery. If eye drops are not successful in reducing pressure, a surgical or laser procedure is the next step. 

These procedures include:

• Tube shunt surgery: This type of surgery is most often recommended. Tube shunt surgery reduces the pressure immediately and has higher rates of success than other surgeries, such as trabeculectomy.
• Cyclophotocoagulation: If vision is very poor, some doctors will pursue a less invasive procedure, called cyclophotocoagulation. This involves a type of laser that destroys the ciliary body, which is the part of the eye that produces fluid. There are multiple techniques available for this laser procedure.

Patients must consider common risk factors for eye disease, visit their doctor for annual checkups, and report any changes in eye health or vision as soon as they occur to avoid the devastating effects of neovascular glaucoma.

Additional information on neovascular glaucoma can be found on the BrightFocus Foundation website.

*Shen, C. (2019, June 11). Neovascular Glaucoma. American Academy of Ophthalmology EyeWiki. https://eyewiki.aao.org/Neovascular_Glaucoma 

Any sources from outside of Prevent Blindness do not imply an endorsement from Prevent Blindness. The contents of the material used are the responsibility of the authoring organization, Responsum Health.