Retinal Occlusion Retinal Occlusion

Arteries carry blood from the heart to vein occlusion have pain, and some have other parts of the body, and carry no symptoms. the blood back to the heart. A blockage in Complications of RVO an artery or vein is called an occlusion. Macular edema. The macula is the small, The is the layer of light- central area of the retina that allows sharp, sensitive tissue that lines the back of detailed vision, such as that necessary for the . It converts light into signals reading. Blood and fluid leaking into the that are sent via the to the macula cause swelling, a condition called brain, where they are recognized as macular edema, which causes blurring images. Conditions that affect the retina and/or loss of vision. affect the ability to see. Neovascularization. RVO can cause RETINAL VEIN OCCLUSION the retina to develop new, abnormal When a retinal vein is blocked, it cannot blood vessels, a condition called drain blood from the retina. This leads to neovascularization. These new vessels hemorrhages (bleeding) and leakage of may leak blood or fluid into the vitreous, fluid from the blocked blood vessels. the jelly-like substance that fills the There are two types of retinal vein occlusion: inside of the eye. Small spots or clouds, Central retinal vein occlusion (CRVO) called floaters, may appear in the field of is the blockage of the main retinal vein. vision. With severe neovascularization, Branch retinal vein occlusion (BRVO) the retina may detach from the back of is the blockage of one of the smaller the eye. branch veins. Neovascular glaucoma. New blood Causes of RVO vessels in certain parts of the eye can Certain conditions increase the risk of cause pain and a dangerous increase in developing retinal vein occlusion. These pressure inside the eye. include diabetes, glaucoma, high blood Blindness. The complications of RVO, pressure, high cholesterol, vascular (blood especially if they are not treated, can vessel) disease, and blood disorders. lead to irreversible loss of vision. Symptoms of RVO Diagnosis of RVO RVO often causes a sudden, painless Ophthalmoscopy. The changes caused blurring or loss of vision. It may also by RVO may be seen by examination of cause a person to see floaters or flashing the retina with an instrument called lights. However, some people with retinal an ophthalmoscope. Fluorescein angiography. This is a test Symptoms of RAO procedure in which a dye that is injected RAO causes sudden, painless, complete into a vein in the arm travels to the retinal (central artery) or partial (branch blood vessels. Special photographs allow artery) loss of vision. Atherosclerosis, the physician to see the vessels. diabetes, heart disease, glaucoma, high Treatment of RVO blood pressure, and high cholesterol are Currently, there is no known way to cure among the conditions that increase the RVO. Treatment with steroids, either by risk of RAO. injection or via an implant (Ozurdex), or Complications of RAO with drugs such as ranibizumab and Unless the blood supply to the retina can be bevacizumab that are injected into the eye restored quickly, the affected area will not to prevent new blood vessel growth and survive, and vision loss will be permanent. leakage, may lead to improvement in Diagnosis of RAO vision. In some cases, laser treatment The changes caused by RAO may be may be used. seen by examination of the retina with Someone who has had an RVO has an an ophthalmoscope. increased risk of having another one. This Treatment of RAO risk may be reduced with management of any conditions, such as diabetes or There is no treatment that has been proven high blood pressure, that contribute to to be successful. Potential treatments development of RVO. include eye massage, removal of fluid from the eye, oxygen therapy, and injection RETINAL ARTERY OCCLUSION of drugs that dissolve clots. The outcome When a retinal artery is blocked, blood is more likely to be better if the occlusion is cannot get to the retina. Like RVO, RAO partial and treatment is begun promptly. may affect the or a People with RAO often have serious branch artery. underlying health problems that require Causes of RAO thorough medical evaluation. RAO is usually caused by a small clot.