eye disorders
Blockage of Central Retinal Veins and Branch Retinal Veins
Introduction
A vein in the retina (the transparent, light-sensitive structure at the back of the eye) may become blocked, causing sudden, painless loss of vision. Doctors typically make the diagnosis by looking in the eye with an ophthalmoscope and sometimes by diagnostic tests. Treatment can often improve vision. Thecentral retinal veinis the main vein that drains blood away from the retina. Blockage may occur in the main vein or in its branches. Central retinal vein blockage occurs mainly in older people. Risk factors include High blood pressure Glaucoma Diabetes Increased blood viscosity (thickness) Sometimes the cause of the blockage is unknown. 