Potential Treatments for Macular DegenerationMany potential treatments for macular degeneration are being investigated in laboratories and tested in human clinical trials. On this page, you will find the following:
AvastinPhysicians have been using a drug called Avastin® as an “off-label” treatment for wet age-related macular degeneration, with promising results. Avastin has been approved by the U.S. Food and Drug Administration (FDA) as a blood vessel growth inhibitor used to treat colorectal cancer, but is not approved for macular degeneration. Avastin is manufactured by the same pharmaceutical company, Genentech, Inc., that makes Lucentis®, which was approved by the FDA in 2006 as a therapy for wet macular degeneration. Lucentis is actually a form of Avastin developed by Genentech to specifically treat macular degeneration through the use of smaller molecules for increased penetration of the retina. Both are similarly administered through a series of injections into the vitreous portion of the eye (the clear jelly-like substance that fills the eye from the lens back to the retina) at regular intervals over the course of months or a year. While Lucentis costs approximately $2,000 per injection, each Avastin treatment costs between $20 and $100, and many physicians believe both drugs are equally effective. Since much smaller doses of Avastin are used for macular degeneration than for cancer treatment, physicians normally use a compounding pharmacy to obtain the correct dosage. In 2008, the National Eye Institute (NEI) of the National Institutes of Health (NIH) began conducting clinical trials (Comparison of Treatments Trials or CATT) to study the relative efficacy and safety of Avastin and Lucentis. Source: This information was obtained in part from the National Eye Institute of the National Institutes of Health and ClinicalTrials.gov. BevasiranibEvaluated for: Wet age-related macular degeneration (AMD) How it works: Bevasiranib was developed by Acuity Pharmaceuticals, and is now in clinical trials. Current treatments, such as Lucentis®, and Bevasiranib both target Vascular Endothelial Growth Factor (VEGF), a protein that promotes blood vessel growth in wet macular degeneration. However, Bevasinirab is an interfering RNA rather than a VEGF antagonist (e.g., Lucentis, which contains antibody fragments that bind to and inhibit VEGF activity). As a small interfering RNA (siRNA), Bevasiranib “silences” the genes that produce VEGF, and thus, slows the growth and leakage of abnormal blood vessels. Bevasiranib is injected directly into the eye, but less frequently than current VEGF antagonist treatments. Most common side effects: Swelling and inflammation at the injection site. No adverse side effects have yet been reported; however, this experimental drug is still in clinical trials. Status: Phase II clinical trials of Bevasiranib were completed in late 2006. In January 2008, recruiting began for Phase III trials. These trials will examine the safety and efficacy of administering three Lucentis injections, followed by injections of Bevasiranib every 8-12 weeks. The study should be completed in 2010. Cortical ImplantsEvaluated for: Wet age-related macular degeneration (AMD) How it works: Similar to the retinal implant, cortical implants collect and record images and convert them into visual stimuli that can be processed by the brain. Unlike those put into the retina, cortical implants bypass the eye altogether and are instead inserted into the part of the brain known as the visual cortex, which is responsible for processing visual signals sent from the eye. The patient must wear special head gear, a mini camera and sensor, that are connected to a computer and then to the implant. Most common side effects: Possible infection and swelling on or around the implant. Status: Cortical implants are still experimental, and research is continuing. Scientists need to find a material that is small enough, won’t be rejected by the body, and that can be used long-term. Source: This information was obtained in part from ClinicalTrials.gov and the National Eye Institute. DietSome studies indicate that eating a diet high in carotenoids, antioxidants (such as vitamins C and E), and omega-3 fatty acids may reduce the risk of developing age-related macular degeneration (AMD). However, more research is required before definitive statements can be made. Carotenoids are compounds found in plants, and have been associated with defending against age-related macular degeneration, cancer, heart disease, diabetes and a number of other medical conditions. Dark green, yellow and orange fruits and vegetables (especially those high in the carotenoids known as lutein and zeaxanthin), appear to best protect against development of age-related macular degeneration. Lutein and zeaxanthin are the primary pigments in the macula and are thought to guard the retina from ultraviolet light. These carotenoids normally occur together, in different ratios, in food. Lutein is found in dark, leafy greens such as spinach, collard greens and kale, as well as in okra, broccoli, papaya, oranges, kiwi, mango, green beans, peaches, sweet potatoes, lima beans, squash, red grapes and green bell pepper. Yellow corn, honeydew melon, squash, oranges, mango, kale, apricots, peaches and orange bell pepper are good sources of zeaxanthin. Fruits and vegetables abundant in vitamin C include green peppers, citrus fruits, tomatoes, broccoli, strawberries, yams, leafy greens and cantaloupe. Vitamin E is found in eggs, fortified cereals, fruit, wheat germ, green leafy vegetables, nuts/nut oils, vegetable oils and whole grains. Wild salmon, tuna, sardines, walnuts and flaxseed oil are good sources of omega-3 fatty acids. VitaminsThe National Eye Institute’s Age-Related Eye Disease Study (AREDS) found that taking a specific high dose formula of antioxidants and zinc (500 milligrams of vitamin C, 400 International Units of vitamin E, 15 milligrams of beta-carotene, 80 milligrams of zinc as zinc oxide and two milligrams of copper as cupric oxide) may delay or prevent intermediate macular degeneration from progressing to the advanced stage. There is no evidence, however, that the AREDS formula provided any benefit to people with early stage macular degeneration. Patients with intermediate macular degeneration in one or both eyes or advanced macular degeneration (dry or wet) in one eye but not the other eye should consider taking the formula. Consult a physician before taking any supplements; the AREDS formula may be contraindicated for certain medical conditions or may react negatively with some medications. Implantable Miniature TelescopeYear Approved by the FDA: Approval was expected in late 2007, but did not occur. Evaluated for: Advanced or end-stage age-related macular degeneration (AMD) How it works: The Implantable Miniature Telescope (IMT) was developed by Dr. Isaac Lipshitz of VisionCare, Inc. It may help those with end-stage wet macular degeneration gain back some vision. The IMT is a very tiny telescope that is inserted into one eye. The eye with the implant provides central vision (the area of vision lost in macular degeneration), while the other eye provides peripheral vision. The telescope projects images over healthy areas of the retina, rather than those damaged by the disease. The IMT can usually be implanted by an eye surgeon during an outpatient surgical visit. After surgery, patients must participate in a structured vision rehabilitation program to become accustomed to performing daily activities using the device. Most common side effects: There may be temporary changes in the pressure inside the eye, inflammation on or around the device and corneal swelling. Status: The Ophthalmic Devices Panel of the U.S. Food and Drug Administration (FDA) recommended approval of a second generation implantable telescope, the Lipshitz Macular Implant (LMI), on March 27, 2009. Macular TranslocationEvaluated for: Wet age-related macular degeneration (AMD) How it works: In wet macular degeneration abnormal blood vessels grow under the retina, often leaking and causing scarring of the macula, the portion of the retina responsible for sharp, clear, "straight-ahead" vision. This damage to the macula may eventually become permanent, but it usually only affects the macular region leaving the surrounding retinal tissue healthy. In macular translocation surgery, the macula is moved away from the damaged area and placed in a new, healthier location. The aim of this surgery is to try to maintain or recover some central vision. This surgery normally works best when vision loss is recent. Healing after the procedure may take several months. However, most patients experience some improvement in vision. A second corrective surgery may be needed to reposition the muscles of the eye, as moving or repositioning the macula can cause double or tilted vision. Most common side effects: The risks include cataract formation, infection, bleeding within the eye, retinal detachment, reduced vision and total vision loss. Status: Macular translocation surgery is still an experimental procedure. Radiation TherapyEvaluated for: Wet age-related macular degeneration (AMD) How it works: Numerous studies have reported the benefits of laser photocoagulation therapy for the treatment of wet macular degeneration. However, photocoagulation cannot be used for those with “subfoveal” macular degeneration in which the abnormal blood vessels are located under the fovea, in the center of the macula. Since almost 90% of age-related macular degeneration is subfoveal, scientists are searching for alternative treatment options for these cases. One option is radiation therapy in which a low-dose of radiation is used to inhibit the growth of abnormal blood vessels and subsequent scar formation. Although the exact mechanism is not fully understood, researchers believe that radiation causes abnormal vessels to regress and likely promotes cell inactivation to inhibit growth of new vessels. Fluid and blood are reabsorbed, reducing the risk for further leakage or bleeding. Radiation treatment can potentially stabilize and/or preserve vision and prevent of progression to advanced stage macular degeneration. Most common side effects: Macular scarring, subsequent abnormal vessel growth and/or hemorrhage. Status: Several clinical studies have reported that wet macular degeneration patients who receive radiation therapy seem to benefit significantly. In 2008, a Phase III clinical trial called CABERNET began recruiting participants. CABERNET will test the effectiveness and safety of a one-time dose of Strontium 90 beta radiation (through the Epi-Rad90™ Opthamalic System developed by NeoVista™, Inc.) combined with several injections of Lucentis®. This trial is expected to end in 2011. RetaaneEvaluated for: Wet age-related macular degeneration (AMD) How it works: Retaane (anecortave acetate) is an angiostatic cortisene designed to inhibit the new, abnormal blood vessel growth (angiogenesis) that occurs in wet macular degeneration. This investigational drug was developed by Alcon®. It is administered behind the eye to the surface of the sclera using a blunt-tipped, curved tube. The tube does not puncture the eye, so the procedure reduces the risks associated with the injection of compounds into the eye including infection and retinal detachment. Retaane is also administered less often than currently available angiogenic inhibitors – it is usually given once every six months. Most common side effects: No adverse side effects have yet been reported; however, this experimental drug is still in clinical trials. Status: In September 2007, upon completion of some clinical trials on Retaane, the Food and Drug Administration (FDA) informed Alcon that the drug was “approvable”, but that further trials were necessary before final approval. Alcon stated they did not plan to begin more trials due to difficulties finding volunteers and the availability of other macular degeneration therapies. In July 2008, after an interim analysis of study data, Alcon terminated a program evaluating the effect of Retaane on the risk of blood vessel development associated with macular deg. Alcon will continue to study Retaane as an eye-pressure lowering glaucoma therapy. Retinal ImplantsEvaluated for: Wet age-related macular degeneration (AMD) patients with moderate to severe vision loss. How it works: Retinal implants, also known as artificial retinas, are designed to replace lost photoreceptors (the light-sensing cells of the eye) and other retinal tissue damaged by abnormal vessel growth and scarring associated with wet macular degeneration. In most devices, a small video camera is mounted to a pair of eyeglasses. The camera collects images and sends this visual data to microelectrodes implanted in the retina of the eye. The microelectrodes, in turn, send electrical impulses to the part of the brain that can process the visual signals. Most common side effects: Infection and retinal detachment may occur. Other side effects may vary from patient to patient depending on the eye’s ability to tolerate the implanted device. Status: Though still in the testing and development stages, these devices may help those with advanced macular degeneration who have lost all or most of their vision. A few volunteers have already received retinal implants and are able to detect light and distinguish between some objects; further trials are planned. Numerous researchers at various institutions and universities worldwide are investigating retinal implants, including groups at the U. S. Department of Energy, the Doheny Eye Institute (University of Southern California) and the Boston Retinal Implant Project at Harvard and MIT. Further studies are needed to determine the optimal location for implant placement, and to find a material compatible with the normal eye tissue for long-term use. RheopheresisEvaluated for: Dry age-related macular degeneration (AMD) How it works: Rheopheresis or the RHEO™ procedure has been tested for use in treating dry macular degeneration. In this procedure, the blood is removed from the body through an IV, filtered and returned. The filtering is an attempt to remove large molecules of certain substances (e.g., cholesterol, large proteins and fatty particles) that may lead to the progression of macular degeneration. These substances are thought to reduce the flow of blood to areas of the eye critical for vision. By removing these substances and improving blood flow to the eye, RHEO is believed to increase the supply of oxygen and nutrients necessary for macular cell health. Most common side effects: Hypotension (low blood pressure), nausea, dizziness, fainting and bruising at the sites of IV insertion. Status: In early 2007, the Food and Drug Administration cleared the way for Phase III trials of RHEO. However, due to current financial problems within OccuLogix, the company that developed RHEO, these trials have been suspended indefinitely and are not recruiting volunteers. Data is still being analyzed from two previous trials of RHEO. In 2007, researchers in Vienna, Austria began recruiting participants for a Phase III trial studying rheohemapheresis (same procedure) in conjunction with lutein supplements. Submacular SurgeryEvaluated for: Wet age-related macular degeneration (AMD) How it works: In submacular surgery for wet macular degeneration, lesions associated with bleeding beneath the retina, abnormal blood vessels and scar tissue are removed, rather than sealed or partially destroyed. It was believed that surgery to remove abnormal vessels might halt enlargement of the visual defect, spare the cells in the central macula, and allow the surrounding or adjacent tissue to function normally. Most common side effects: Cataract formation, macular holes and retinal detachment. Status: From 1997 to 2003, the National Eye Institute (NEI) sponsored the Submacular Surgery Trials (SST). Upon completion of the trials, in November 2004, the NEI reported that vision did not substantially improve for patients with macular degeneration who underwent submacular surgery. Disclaimer: The information provided in this section is a public service of the American Health Assistance Foundation, and should not in any way substitute for the advice of a qualified healthcare professional and is not intended to constitute medical advice. Although we take efforts to keep the medical information on our website updated, we cannot guarantee that the information on our website reflects the most up-to-date research. Please consult your physician for personalized medical advice; all medications and supplements should only be taken under medical supervision. The American Health Assistance Foundation does not endorse any medical product or therapy. Source: This information is sourced from ClinicalTrials.gov and the National Eye Institute. Last Reviewed On: 09/11/09 |
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