Retinal Vein Occlusions (CRVO and BRVO)
The retina is made up of cells that capture the light and send messages to the brain and blood vessels that give nourishment to the cells to keep them healthy. If the veins get clogged, they can cause a backup of fluid it is called an occlusion and could cause a backup of fluid in the retina. Think of it like a kink in a garden hose, wherein blood continues to enter the retina, but cannot drain out, and fluid backs up and leaks out. The macula can swell from this excess fluid causing blurry vision. Eventually, without proper circulation, cells can die, and more vision can be lost. A blockage of the retina’s main vein is called a central retinal vein occlusion (CRVO), while a blockage in a smaller vein is called a branch retinal vein occlusion (BRVO).
Our doctor and technician staff will likely perform OCT, Fluorescein Angiogram, and eye exam to inspect the retina, blood vessels, and how the blood is flowing through them. The doctor will also partner with your primary care doctor to evaluate the rest of the blood vessels in the body and possibly order additional blood tests or carotid artery Doppler tests. People with high blood pressure, diabetes, glaucoma, blood-clotting conditions, and arteriosclerosis are at higher risk of developing retinal vein occlusions.
If a vein occlusion occurs, you may notice blurry vision in part or all of one eye, depending on which vein is blocked. Shadows from tiny clumps of blood floating the in vitreous may also cause you to see floaters. Vein occlusions may cause complications such as:
- Macular edema – fluid from the blocked blood vessels leak into the macula, the center and most precise vision area of the retina, and the swelling causes a decrease in vision
- Neovascularization – the formation of new blood vessels in response to the lack of oxygen reaching the tissues. These abnormal blood vessels are weak and bleed easily
- Neovascular glaucoma – new blood vessels grow into the iris and drainage channels in the front of the eye that can lead to a painful acute glaucoma attack
- Ischemia – sections of retina tissue that have starved and died
There is treatment for the complications of the occlusion, however, veins cannot be unblocked. Eye injections are the most common treatment when there is swelling or new blood vessel growth. Laser treatment will be suggested if there are areas in the retina that are severely lacking blood flow. Both of these treatments sound unpleasant, but our doctors at Retina Specialists of Michigan work hard to keep our patients at ease and pain free. Most, but not all people notice improvement in vision a few months after treatment. Call us at (616) 954-2020 if you’re having any symptoms.