Diagnosing a Retinal Stroke

Dr. Kirsch or Dr. Hairston may suggest a test called a fluorescein angiogram. This test involves injecting a vegetable dye into a vein in the arm and taking black and white photographs of the retina (these are NOT X-Rays) as the dye circulates through the eye. The photographs allow the doctor to determine how much fluid leakage is present and where the leaky blood vessels are located. The fluorescein angiogram pictures also assist and guide laser treatment. A noninvasive Ocular Computed Tomogram (OCT) will also be performed to determine the thickness of the retina.

Treatment of a Retinal Stroke

In many patients with branch vein occlusions, especially if there is bleeding or swelling in the macula, laser treatment may restore vision or prevent further loss of vision. Using a contact lens placed on the front of the eye, up to 250 laser spots are placed in the macula. The procedure is painless, takes about 5 minutes and is performed in the office. The major side effect is that some patients actually see the laser spots after the treatment is finished. These usually fade away over the next few weeks. The swelling of the retina may take up to four months to subside. If the swelling does not go away after that time or if it comes back later, the laser treatment can be repeated. Although the vision may be improved in many patients, the laser treatment is designed to stabilize the eyesight and prevent it from getting worse.

Newer Treatment

Recently, there has been a great deal of research regarding the use of medications which inhibit Vascular Endothelial Growth Factor (VEGF) to treat retinal vein strokes. VEGF is a family of 6 proteins produced all over the body (including in the eye) that are critically important in the development of both normal and abnormal new blood vessels. In retinal vein strokes, VEGF is produced in abnormally high amounts causing the leakiness of the blood vessels that causes macular edema and the formation of the abnormal new blood vessels that can arise from retinal vein strokes.

All anti-VEGF treatment is administered as an injection into the vitreous cavity. This procedure is performed in the office. The surface of the eye is numbed with drops and then an anesthetic injection of lidocaine is given under the conjunctiva (the “skin” covering the white part of the eye). The eye is then thoroughly cleaned and sterilized with betadine and antibiotic drops. The anti-VEGF medication is injected through the anesthetized area into the vitreous cavity using a very tiny needle. The procedure itself is painless and straightforward. However, it is considered an invasive procedure because we are entering the eye itself and there is a rare chance of complications such as cataract, retinal detachment, bleeding or infection. These complications occur in less than one in a thousand injections. Occasionally, the volume of medication injected temporarily interrupts the circulation to the eye and it might be necessary for the surgeon to remove some fluid from the front of the eye to restore the normal circulation. All patients receiving an injection are asked to take antibiotic drops for four days after the injection to lessen the chance of infection. These injections are usually repeated every 4 to 6 weeks as necessary until the problem is resolved.

Three VEGF Options

There are three anti-VEGF medications that may be used to treat retinal vein strokes: Avastin, Lucentis and Macugen. Although all three medications are FDA approved, they are not FDA approved for the treatment of retinal vein strokes. Lucentis and Macugen are FDA approved for treating wet macular degeneration while Avastin is used “off-label” for all eye diseases. Recently, there has been some encouraging news regarding the effectiveness of these medications. In practice, Avastin is usually the drug of choice. It is significantly less expensive than either Macugen or Lucentis and is as or more effective than either. There has been an indication from Medicare and other insurance companies that they will cover the cost of this treatment option for retinal vein strokes.

During the first 6 months after the diagnosis of a retinal vein stroke, your eye will be examined very carefully for the growth of new abnormal blood vessels. In some patients with retinal vein occlusions, the blood vessels supplying the retinal tissue become so damaged they lose the ability to adequately nourish the retina. The eye responds to this situation by increasing the production of VEGF to start growing new blood vessels. Unfortunately, these new blood vessels do not actually meet the need for more nourishment of the retina. The blood vessels can grow on the surface of the retina or in the iris (which is the part of your eye that gives it a blue, green or brown color). The abnormal new blood vessels can cause three major problems leading to loss of vision. First, if they grow on the iris, the new blood vessels can cause a very serious type of glaucoma because they block the canal that normally drains fluid from the front part of the eye. Second, if they grow on the retina, they can break and cause bleeding into the large cavity in the back part of the eye. Third, the blood vessels can eventually form large sheets of scar tissue that can pull on the retina and lead to a retinal detachment. If not diagnosed and treated promptly, these problems often have to be corrected by advanced surgery.

Laser Treatment

The main goal of treating these new vessels in the eye is to promptly stop them from growing and therefore avoid major surgery. Laser treatment is usually recommended when new blood vessel growth is detected. The laser treatment is different from the laser performed for swelling and bleeding in the macula. In this case, up to 2,000 laser spots are placed around the front part of the retina, away from the macula. The procedure is performed in the office during one or two treatment sessions. Some mild discomfort may be felt for a few days afterwards. The other common side effect is a mild decrease in the “side” or peripheral vision, especially at night. The new blood vessels usually begin to shrink within a week of the treatment. Additional laser treatments can be performed if the blood vessels don’t go away entirely or if they regrow. In most patients, the laser treatments cure this problem permanently. Anti-VEGF injections can also be used to treat new blood vessel growth.

In Summary

While strokes of the retinal veins cannot always be prevented, they can often be successfully treated. It is especially important to keep diseases such as glaucoma, diabetes and high blood pressure under good control to minimize the damage from these strokes and to try to prevent them from occurring in your other eye. Prompt diagnosis and laser treatment may prevent further vision loss and may restore vision in many patients. Working together with you and your primary doctor, Dr. Kirsch and Dr. Hairston can help to preserve or restore the precious gift of sight.