Retinal Vein Occlusion
Arteries carry oxygen-rich blood from the heart and lungs to every organ in the body, and veins return the oxygen-depleted blood back to the heart. In the retina, all veins funnel into one, large vein called the the central retinal vein. A blockage in any of these tributary veins results in a backup of blood flow and leakage of blood and fluid from the blocked vein into the reitna. This creates retinal edema, or swelling, and ischemia, lack of oxygen, and results in decreased visual acuity.
Risk factors for retinal vein occlusion include diabetes, high blood pressure, high cholesterol and glaucoma. Roughly 25% of patients with a retinal vein occlusion will have gradual, spontaneous improvement in vision. The other 75% of patients the vision fails to improve and may even worsen.
There are several treatment options to improve vision in patients with vision loss due to macular edema. These options include intravitreal injections (injections into the jelly-like substance that fills the back of the eye) with a vascular endothelial growth factor (VEGF) inhibitor (anti-VEGF). There are currently 2 FDA-approved anti-VEGF medications: Lucentis and Eylea, and 1 off-label anti-VEGF medication called Avastin. In addition, injection of steroids (Triamcinolone and Ozurdex) as well as laser therapy can be used to treat certain types of venous occlusions.
It is essential that patients with venous occlusions have frequent follow-up visits with their retinal specialist to check for new blood vessel growth (neovascularization). These “new”, abnormal blood vessels are very fragile and have the propensity to leak and spontaneously rupture.