Branch Retinal Vein Occlusions (BRVO)
Most people know high blood pressure
and other vascular diseases pose risks to overall health, but many
may not know that high blood pressure can affect vision by damaging
veins in the eye. High blood pressure is the most common condition
associated with BRVO. About 10 to 12 percent of the people who have
BRVO also have glaucoma (high pressure in the eye).
Branch retinal vein occlusion blocks small veins in the retina,
the layer of light-sensing cells at the back of the eye. If the
blocked retinal veins are ones that nourish the macula, the part
of the retina responsible for straight-ahead vision, some central
vision is lost. During the course of vein occlusion, sixty percent
or greater will have swelling of the central macular vision area.
In about one third of people, this macular edema will remain for
over one year.
BRVO causes a painless decrease in vision, resulting in misty or
distorted vision. If the veins cover a large area, new abnormal
vessels may grow on the retinal surface, which can bleed into the
eye and cause blurred vision.
There is no cure for BRVO. Finding out what caused the blockage
is the first step in treatment. Your ophthalmologist may recommend
a period of observation, since hemorrhages and excess fluid may
subside on their own. Depending on how damaged the veins are, laser
surgery may help reduce the swelling and improve vision. Laser surgery
may also shrink the abnormal new blood vessels that are at risk
of bleeding.
If you have had a branch retinal vein occlusion, regular visits
to your eye doctor are essential to protect vision. You would also
need to follow-up with your family doctor to check for diseases
such as high blood pressure, high cholesterol and diabetes.