Age-related macular degeneration (AMD) is the leading cause of blindness in people over 50 years of age. It is caused by the breakdown of the central portion of the retina (the highly sensitive part of your eye that works like the film in a camera to capture the picture) called the macula. The macula is responsible for the fine central vision in the eye that is needed for driving a car, reading fine print, recognizing faces, etc. There are two types of macular degeneration: dry and wet. In the wet form of macular degeneration, abnormal blood vessels grow in the back of the eye. Sometimes these vessels leak blood or fluid that causes blurred or distorted vision. Without treatment, vision loss may be quick and severe.
There are other eye conditions that cause loss of vision due to abnormal growth of blood vessels in the back of the eye. These can occur even in young patients, and include, but are not limited to, conditions such as high myopia (nearsightedness), histoplasmosis, angioid streaks, and eye injury. Sometimes there is no known reason for the abnormal blood vessels. Without treatment, vision loss may be quick and severe.
Macular edema, or swelling around the macula,, is edema that affects vision but does not respond adequately to the usual treatment methods. It can occur with conditions such as central retinal vein occlusion and diabetic retinopathy. Without effective treatment, vision loss could progress and become permanent.
Off-Label Use of Avastin - Benefits
Avastin was not initially developed to treat your eye condition. Based upon the results of clinical trials that demonstrated its safety and effectiveness, Avastin was approved by the Food and Drug Administration (FDA) for the treatment of metastatic colorectal cancer. As a condition of approval, the manufacturer produced a “label” explaining the indications, risks, and benefits. The label explains that Avastin works by blocking a substance known as vascular endothelial growth factor or VEGF. Blocking or inhibiting VEGF helps prevent further growth of the blood vessels that the cancer needs to continue growing.
Once a device or medication is approved by the FDA, physicians may use it “off-label” for other purposes if they are well-informed about the product, base its use on firm scientific method and sound medical evidence, and maintain records of its use and effects. Ophthalmologists are using Avastin “off-label” to treat AMD and similar conditions since research indicates that VEGF is one of the causes for the growth of the abnormal vessels that cause these conditions. Some patients treated with Avastin had less fluid and more normal-appearing maculas, and their vision improved. Avastin is also used, therefore, to treat macular edema, or swelling of the macula.
Possible Avastin Limitations
Here are some examples of common drugs being used “off-label”:
1) Eye antibiotics
3) Zoloft & Paxil
The goal of treatment is to prevent further loss of vision. Although some patients have regained vision, the medication may not restore vision that has already been lost, and may not ultimately prevent further loss of vision caused by the disease. After the pupil is dilated and the eye is numbed with anesthesia, the medication is injected into the vitreous, or jelly-like substance in the back chamber of the eye. Avastin is administered by an injection into your eye as needed at regular intervals (about every four to six weeks); your ophthalmologist will tell you how often you will receive the injection, and for how long.
You do not have to receive treatment for your condition, although without treatment, these diseases can lead to further vision loss and blindness, sometimes very quickly. Other forms of treatment are available. At present, there are three FDA-approved treatments for neovascular age-related macular degeneration: photodynamic therapy with a drug called Visudyne and injection into the eye of two other VEGF inhibitors drugs called Macugen™ and Lucentis™. Although both of these treatments have been proven to slow down the rate of visual loss, most people do not get back better vision. Dr. Deupree will discuss with you the benefits and risks associated with these other choices of treatment. In addition to the FDA-approved medications, some ophthalmologists use intravitreal KenalogTM—a long-acting cortisone-like drug - “off-label” to treat eye conditions like yours.