Retinal Vein Occlusion

The retina is the light sensing tissue at the back of the eye. The veins drain blood out of the retina and return it to the heart.

A retinal vein occlusion means that a vein in the retina of the eye has become blocked. Blockage, or occlusion, in the vein prevents adequate blood flow in the affected area. The walls of the vein leak blood and excess fluid into the retina. Central and branch retinal veins are sometimes associated with high blood pressure and diabetes.

There are two types of retinal vein occlusion:

1. Central retinal vein occlusion (CRVO)
2. Branch retinal vein occlusion (BRVO)

Symptoms

The main symptom of retinal vein occlusion is blurred vision. It occurs when the excess fluid leaking from the vein collects in the macula. The macula is the central area of the retina that is responsible for central, detailed vision. If the macula swells with excess fluid, vision blurs.

Another symptom is floaters. Floaters can appear as spots, which interfere with vision.

When retinal blood vessels are not working properly, the retina may grow abnormal blood vessels (neovascularization) that are fragile. They can bleed or leak fluid into the vitreous (the gel-like fluid that fills the center of the eye), causing the floaters.

Pain in the eye sometimes occurs as a complication of severe CRVO. It is caused by excessive eye pressure called neovascular glaucoma.

Diagnosis

After your initial examination, you may be referred to a retina specialist for further evaluation and a test of the retinal circulation called fluorescein angiography. A dye (flourescein) is injected into your arm and then special photos are taken of the inside of your eye when the dye passes through the blood vessels. Your ophthalmologist may also suggest a visit to your family physician to discover and manage any associated medical problems.

A new, non-invasive test called optical coherence tomography (OCT) is available at Retina Care Specialists that may help evaluate how much swelling there is as a result of the branch vein occlusion.

Treatment

There is no cure for retinal vein occlusion. Your ophthalmologist may recommend a period of observation, since hemorrhages and excess fluid may subside on their own.

Laser surgery improves sight in some patients with BRVO and macular edema, but vision does not usually return to normal. Laser surgery is not as helpful in CRVO, but new types of treatment are being evaluated.

Laser surgery is very effective in preventing vitreous hemorrhage and neovavascular glaucoma. However, it does not remove hemorrhage or cure neovascular glaucoma once they are already present. It is best to treat people at risk for these complications before they occur.

Intraocular steroids are being investigated for the treatment of branch and central vein occlusions. At Retina Care Specialists, we are involved in a clinical trial for the investigation of a new medication that may actually improve vision in patients with branch and central retinal vein occlusions. Ask us if you or someone you know may be a candidate for new treatments.