Central Retinal Vein
Occlusion (CRVO)
You probably know high blood pressure and other vascular
diseases pose risks to overall health, but you may not know that they can
affect eyesight by damaging the veins in the eye.
Central retinal vein occlusion (CRVO) blocks the main vein
in the retina, the light-sensitive nerve layer at the back of the eye. The
blockage causes the walls of the vein to leak blood and excess fluid into the
retina. When this fluid collects in the macula-the area of the retina
responsible for central vision-vision becomes blurry.
Floaters in your vision are another symptom of CRVO. When
retinal blood vessels are not working properly, the retina grows new fragile
vessels that leak blood into the vitreous, the fluid that fills the center of
the eye. Blood in the vitreous clumps and is seen as tiny dark spots, or
floaters, in the field of vision.
In severe cases of CRVO, the blocked vein causes painful
pressure in the eye. Retinal vein occlusions commonly occur with glaucoma,
diabetes, age-related vascular disease, high blood pressure, and blood
disorders.
The first step is finding what is causing the vein
blockage. There is no cure for CRVO. Your ophthalmologist may recommend a
period of observation, since hemorrhages and excess fluid often subside on
their own. Laser surgery may be effective in preventing further bleeding into
the vitreous, or for treating glaucoma, but it cannot remove a hemorrhage or
cure glaucoma once it is present.