Central Retinal Vein Occlusion (CRVO) occurs when the main retinal vein is blocked. Because blood can no longer travel smoothly out of the retina, the retina fills with blood and becomes swollen. If blockage is partial, the retina may continue to function adequately. In more severe blockages, permanent retinal damage with loss of vision may occur. CRVO’s are most common in people with high blood pressure, diabetes, or glaucoma. Occasionally, damage to the retina results in abnormal new vessel growth. Further visual loss may develop if the abnormal blood vessels break and bleed into the vitreous cavity, causing a vitreous hemorrhage.
Patients with CRVO usually experience blurred vision from retinal hemorrhage and swelling. Spots, strands, or curtains in the vision may occur due to this condition. Eye pain may be caused by neovascular glaucoma.
In addition to a dilated eye exam, a Fluorescein Angiography may be required during which dye is injected into a vein in the arm. Digital images of the retina are obtained as the dye passes through the eye. Blocked or abnormal blood vessels then become detectable to the physician. Optical Coherence Tomography (OCT), a scanning laser which images a slice or cross section of the retina, may be performed to determine if macular edema is present. These tests aid in diagnosis to help establish the type of treatment needed.
Intravitreal Drug Therapy improves the outcome in patients with CRVO. This procedure involves placing medication into the vitreous or main cavity of the eye. The injected medication acts upon damaged blood vessels to reduce leakage and resolve macular edema. Intravitreal drug therapy may also be recommended to cause regression of new blood vessels. The therapy may involve ongoing treatments, sometimes over many years.
Laser Treatment is often required when CRVO causes complications such as abnormal new blood vessel growth. Laser treatment is used to reverse growth of the new blood vessels. If untreated, these abnormal vessels can cause vitreous hemorrhage and glaucoma. Laser may be applied in several sessions.