Branch Retinal Vein Occlusion (BRVO)

A retinal vein occlusion occurs when one of the veins of the retina becomes blocked and cannot drain blood from the retina normally. This blockage leads to a backup of blood and fluid into the retina and can be seen in the retina as hemorrhages. The amount of swelling in the retina varies and depends on the degree of blockage of the retinal vein. If the blockage involves only one of the smaller retinal veins, it is called a branch retinal vein occlusion. In these cases, hemorrhages and swelling are limited to the area of the retina that is drained by that particular vein. High blood pressure is the most common condition associated with BRVO. 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 but there are effective treatments that can restore sight, sometimes to normal levels.  Depending on how damaged the veins are, laser surgery or injections of medication in or around the eye may help reduce the swelling and improve vision.