Retinal Vein Occlusion
Retinal vein occlusion occurs when the circulation of a retinal vein becomes obstructed by an adjacent blood vessel, causing hemorrhages in the retina.

Swelling and ischemia (lack of oxygen) of the retina as well as glaucoma are fairly common complications. 
 Retinal Vein Occlusion
 
The visual symptoms can vary in severity from one person to the next, and are dependent on whether the central retinal vein or a branch retinal vein is involved.

Patients who experience a branch vein occlusion often notice a gradual improvement in their vision as the hemorrhage resolves. Recovery from a central vein occlusion is much less likely.
Retinal Vein Occlusion 
 
SIGNS AND SYMPTOMS
• Sudden onset
• Blurred or missing area of vision (if a branch vein is involved)
• Severe loss of central vision (if a central vein is involved)
• More common after age 60 (males and females)

DETECTION AND DIAGNOSIS
Vein occlusion is diagnosed by examining the retina with an ophthalmoscope. Fluorescein angiography may be performed in some cases to study the circulation of the retina and to determine the extent of macular edema or swelling.

TREATMENT
Following a vein occlusion, the primary concern is to treat the secondary complications. If areas of the retina are oxygen-deprived, LASER may be used to prevent growth of delicate vessels that could break, bleed or cause glaucoma. The following are common risk factors for vein occlusion:

• Diabetes
• Hypertension
• Cardiovascular disease