Retinal vein occlusion is a blockage of the small veins that carry blood away from the retina. The retina is the layer of tissue at the back of the inner eye that converts light images to nerve signals and sends them to the brain.
Central retinal vein occlusion; Branch retinal vein occlusion; CRVO; BRVO
Retinal vein occlusion is most often caused by hardening of the arteries (
Blockage of smaller veins (branch veins or BRVO) in the retina often occurs when retinal arteries that have been thickened or hardened by atherosclerosis cross over and place pressure on a retinal vein.
Risk factors for retinal vein occlusion include:
Diabetes High blood pressure(hypertension)
- Other eye conditions, such as
glaucoma, macular edema, or vitreous hemorrhage
Because the risk of these disorders increases with age, retinal vein occlusion most often affects older people.
Blockage of retinal veins may cause other eye problems, including:
- Glaucoma (high pressure in the arteries), caused by new, abnormal blood vessels growing in the front part of the eye
- Macular edema, caused by the leakage of fluid in the retina
- Sudden blurring or vision loss in all or part of one eye
Exams and Tests
Tests to evaluate for vein occlusion include:
- Examination of the retina after dilating the pupil
Fluorescein angiography Intraocular pressure
- Pupil reflex response
- Retinal photography
- Slit lamp examination
- Testing of side vision (visual field examination)
Other tests may include:
- Blood tests for diabetes, high cholesterol, and
- Blood tests to look for a clotting or blood thickening (hyperviscosity) problem (in patients under age 40)
The health care provider should closely monitor any blockage for several months. Many harmful effects, such as glaucoma, take 3 or more months to develop after the occlusion.
Many people will regain vision, even without treatment. However, vision rarely returns to normal. There is no way to reverse or open the blockage.
You may need treatment to prevent another blockage from forming in the same or the other eye.
Treatment for the complications of retinal vein occlusion may include:
- Focal laser treatment, if macular edema is present
- Injections of anti-vascular endothelial growth factor (anti-VEGF) drugs into the eye. These drugs may block the growth of new blood vessels that can cause glaucoma. This treatment is still being studied.
- Laser treatment to prevent the growth of new, abnormal blood vessels that leads to glaucoma
The outcome varies. Patients with retinal vein occlusion often regain useful vision.
It is important to properly manage complications, such as macular edema and glaucoma. However, having either of these complications is more likely to lead to a poor outcome.
- Partial or complete vision loss in the affected eye
When to Contact a Medical Professional
Call your health care provider if you have sudden blurring or vision loss.
Retinal vein occlusion is a sign of a general blood vessel (vascular) disease. The same measures used to prevent other blood vessel diseases, such as
These measures include:
- Eating a low-fat diet
- Getting regular exercise
- Maintaining an ideal weight
- Not smoking
Aspirin or other blood thinners may help prevent blockages in the other eye.
Controlling diabetes is important in general, and it may also be helpful for preventing retinal vein occlusion.