What is retinal vein occlusion?
The eye is often compared to a camera. The front of the eye
contains a lens that focuses images on the inside of the back of
the eye. This area, called the retina is covered with special nerve
cells that react to light.
Nerve cells need a constant supply of blood to deliver oxygen
and nutrients. Most people understand what happens in a "stroke." A
small blood clot blocks the flow of blood through one of the
arteries in the brain, and the area that is not getting blood
becomes damaged. This same type of damage can happen anywhere in
the body, not just the brain.
When the flow of blood from the retina is blocked, it is often
because of a retinal vein occlusion. If this happens, the nerve
cells of the retina can die and vision may be lost. Because all of
the blood from the retina drains through one large vein, a blockage
of that vein can affect all the vision in that eye.
Why do people get retinal vein occlusion?
Retinal vein occlusion happens when a blood clot blocks the
vein. Sometimes it happens because the veins of the eye are too
narrow. It is more likely to occur in people with diabetes, and
possibly high blood pressure, high cholesterol levels, or other
health problems that affect blood flow.
How does the doctor know whether someone has a retinal vein
occlusion?
The symptoms of retinal vein occlusion range from subtle to very
obvious. There is painless blurring or loss of vision. It almost
always happens in just one eye. At first, the blurring or loss of
vision might be slight, but it gets worse over the next few hours
or days. Sometimes there is a complete loss of vision almost
immediately.
If these symptoms occur, it is important to schedule an
appointment with your doctor as soon as possible. Retinal vein
occlusion often causes permanent damage to the retina and loss of
vision. It can also lead to other eye problems.
How is retinal vein occlusion treated?
Unfortunately, there is no way actually to unblock retinal
veins. However, the doctor can treat any health problems that seem
to be related to the retinal vein occlusion.
Vision may come back in some eyes that have had a retinal vein
occlusion. About one-third have some improvement, about one-third
stay the same and about one-third gradually improve, but it can
take a year or more to learn the final outcome.