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Arteries enter the back of the eye through the optic nerve and bring oxygenated blood to the retina. Veins carry deoxygenated blood from the retina and exit the eye through the optic nerve. Within the optic nerve the artery and the vein lie side by side. Veins are more compressible than arteries. Occasionally, in diseases such as atherosclerosis the artery becomes enlarged and compresses the vein. Compression of a vein prevents blood from exiting the eye and is known as a vein occlusion. Vein occlusions lead to rupture of the walls of the vein and leakage of fluid and blood into the retina. Vein occlusions may be divided into central vein occlusions where the vein inside the optic nerve is compressed. Sometimes only branches of a vein are occluded (or compressed). This is known as a branch vein occlusion. Both forms can cause vision loss.

What are the risk factors for a vein occlusion?

  • High blood pressure
  • High cholesterol
  • Atherosclerosis
  • Glaucoma
  • Diabetes
  • Abnormally clotting blood "thick Blood"

What are the symptoms of a vein occlusion?

Some will notice sudden blurring of all or part of their vision in one eye. If a branch vein is affected an individual may not notice the vision loss.

How is a vein occlusion diagnosed?

An ophthalmologist can diagnosed a retinal vein occlusion by looking into the eye with a microscope and lens. Occasionally, fluorescein angiography is used to highlight the area of blockage and leakage. Optical coherence tomography may also be used to assess the degree of retinal swelling.

How does a vein occlusion cause loss of vision?

Blockage of a vein causes blood to escape the walls of the vessels. Blood within the eye can block light rays from the retina. Fluid can also leak from broken vessel walls causing the retina tissue to swell and malfunction.

How is vein occlusion treated?

Laser surgery is sometimes used to treat the swelling from leakage of fluid. Injections of medicine can also be used. Your retina specialist will discuss the options with you and determine the best course to take. Sometimes vein occlusions do not need to be treated and will resolve on their own. Vitrectomy surgery has been used in some cases.