Neovascular Glaucoma
Chat Highlights
April 23, 2003

Norma Devine, Editor

On Wednesday, April 23, 2003, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Neovascular Glaucoma."

Moderator:  Doctor Rick, what does "neovascular" mean, and what are the symptoms of neovascular glaucoma (NVG)?  

Dr. Rick Wilson:  "Neovascular" means "new vessels," which are what form in the trabecular meshwork, blocking the drain.  The symptoms are usually cloudy vision, red eye, and often an ache from the elevated IOP (intraocular pressure). 

P:  How high are the pressures? 

Dr. Rick Wilson:  Neovascular glaucoma causes some of the highest IOPs seen in glaucoma.  Often the pressures are as high as 60 or 70 mm Hg. 

P:  Does the IOP go up quickly?

Dr. Rick Wilson:  Usually the IOP goes up over a few weeks, but I have seen it increase even more rapidly.

P:  Is there usually another disease associated with NVG?

Dr. Rick Wilson:  Yes, most often it is diabetes, which causes poor circulation to the back of the eye.  The second most common cause is a vein occlusion (closure) in the back of the eye.

P:  What are the most frequent causes of neovascular glaucoma?

Dr. Rick Wilson:  The most common causes are diabetes and posterior vein occlusion.

P:  Is the treatment for diabetic patients different? 

Dr. Rick Wilson:  Not really.

P:  What percentage of diabetic patients get NVG?

Dr. Rick Wilson:  Only those whose diabetes has not been well-controlled for a long time.  I don't remember ever seeing a percentage.  

P:  Is there frequently a history of chronic uveitis?

Dr. Rick Wilson:  Chronic uveitis is not that common.

P:  Is uveitis in an aphakic eye (no lens) common with NVG?

Dr. Rick Wilson:  That condition more frequently causes an inflammatory glaucoma without new vessel growth.

P:  Is NVG a common form of glaucoma?

Dr. Rick Wilson:  Neovascular glaucoma is not very common, but glaucoma specialists see it frequently.

P:  Are the angles open or closed?

Dr. Rick Wilson:  The angles are closed by the new vessels or by the iris after the fibrovascular tissue contracts the iris and pulls it over the trabecular meshwork.

P:  Can irregular blood vessels going to the cornea cause NVG?

Dr. Rick Wilson:  No.

P:  How is neovascular glaucoma usually treated?  

Dr. Rick Wilson:  The new vessels develop because the retina is not getting enough blood.  The shortage sends a message to the body that more oxygen and nutrients are needed.  In response to that stimulus, the body builds new vessels.  But the vessels grow in the wrong area --  the drain -- and block it.  To stop the vessels from growing, a laser is used to kill the part of the retina that is not getting enough blood.  The elevated IOP is treated with medicines and surgery.

P:  What medicines are used?

Dr. Rick Wilson:  We use medicines that decrease the amount of aqueous humor (fluid) made in the eye.  Prostaglandins -- such as Xalatan, Travatan, and Lumigan -- are usually not used to treat this disease, nor is pilocarpine. 

P:  Is NVG curable?   

Dr. Rick Wilson:  Since the cause is usually a very difficult problem with the blood flow to the back of the eye, it is not curable.  NVG requires continuing treatment.

P:  Is there a particular age range of people with NVG?

Dr. Rick Wilson:  Usually NVG occurs in older patients, but often juvenile diabetics get the disease at a young age, often in their twenties. 

P:  Is hyperthyroidism associated with this condition?

Dr. Rick Wilson:  Not as a rule.

P:  Do people with NVG often have other blood-vessel diseases?  If so, what are they?  

Dr. Rick Wilson:  Strokes and loss of circulation to the lower extremities are common. 

P:  Can irregular blood vessels going to the cornea cause NVG?

Dr. Rick Wilson:  No.

P:  Do the medicines that decrease the amount of aqueous in the eye also slow down metabolism?

Dr. Rick Wilson:  No, except for oral medications like Diamox or Neptazane, which can make patients feel tired, weak, or washed out.

P:  Do the medicines used for NVG lower blood pressure?

Dr. Rick Wilson:  Occasionally, beta blockers can lower blood pressure.   Calcium channel blockers may do that more prominently, but are only used in normal-tension glaucoma, and not commonly.

End of highlights for April 23, 2003.

On April 30, Dr. Werner discussed "Implantation of Glaucoma Drainage Devices" in the Chat room. Click here for highlights of that meeting.

Click here for the most recent glaucoma chat highlights and links to the chat archives.

Click here for upcoming glaucoma chat events.