Scientists believe that many factors can influence the development, severity, type, and rate of progression of macular degeneration. Genetics, diet, age, and environment may all play a role. Unfortunately, it is not well understood how these factors interact to lead to someone developing macular degeneration.1
Although the exact causes of macular degeneration are not well known, research is promising in treating the disease.
Gene therapy
Gene therapy may be an alternative to current therapies. A single injection of a harmless virus carrying the therapeutic gene is inserted into the eye. The goal of this therapy is to help the person with macular degeneration make their own protection against further damage from the disease. New gene therapy options are currently in clinical trial, expected to be available to the public within a few years.1-4
Stem cell therapy
Scientists are studying the possibility of using stem cells to regenerate certain macular cells in people with advanced age-related AMD. Stem cells are special cells capable of growing and changing into many different cell types, including retinal pigment epithelial cells.2
Stem cell therapy has generated great excitement and shows some early promise as a possible treatment to restore sight. This therapy may take up to 15 years to be proven safe and effective for human use.2
Medicines for macular degeneration
Years of research have yielded major gains in developing drugs used to treat wet AMD. Additionally, research gains are showing promising results for the treatment of dry AMD.
Anti-VEGF drugs
In the past, drugs that target a specific protein have been the only injectable medicine available. These medicines, known as anti-vascular endothelial growth factor (anti-VEGF), need to be injected into the eye every 4 to 12 weeks, depending on the person. Anti-VEGF drugs decrease the amount of fluid from wet AMD.5
A pill form of anti-VEGF is currently being developed; however, this drug has many unwanted side effects. This type of drug will likely take at least 5 years to prove its safety and efficacy.2
Longer-lasting anti-VEGF drugs provide treatment with fewer injections. Beovu® (brolucizumab-dbll) is approved by the U.S. Food and Drug Administration (FDA) for the treatment of wet AMD. About 1 in every 3 people taking Beovu are able to wait up to 3 months before their next injection. Beovu is new, but it may provide a better option for those with wet AMD.2,6
Two additional longer-lasting anti-VEGF drugs, Abicipar-pegol and Sutent® (sunitinib), are in clinical trial for treating wet AMD and may take years to receive FDA approval.2
Complement inhibitors
Exciting new treatments for dry AMD are being developed. APL-2 and Zimura® (avacincaptad pegol) are injectable drugs that work to stop the complement activation system that is responsible for inflammation, tissue damage, and blood vessel growth. Both drugs have shown promising results slowing the long-term degeneration in dry AMD and are currently in clinical trial.2,7
Researchers are also looking into developing injectable drugs that will block runt-related transcription factor 1 (RUNX1), which is linked to abnormal blood vessel growth in the retina.8
Other medicines
The oral antibiotic Oracea® (doxycycline) is being tested for treatment of dry AMD and the geographic atrophy that may result. Geographic atrophy may occur in advanced dry AMD and refers to the areas of the retina where cells waste away and die. Oracea is not yet approved for use. Clinical trials suggest that some side effects include stomach upset, rash, and sensitivity to sunlight.2,9
Metformin is a popular drug that treats diabetes. Metformin is currently in clinical trial to treat dry AMD inflammation. Results of previous trials have been promising.2
Eye drops
An eyedrop for the treatment of wet AMD could potentially be the first at-home treatment for wet AMD. This drug has had animal testing and requires human clinical trials to be proven safe and effective.2
Radiation therapy
Radiation therapy is being tested on the safety and efficacy of slowing the growth of blood vessels in wet AMD. Radiation therapy may decrease the need for injection therapy. However, radiation therapy has its own side effects. This type of therapy is still in clinical trials and is not yet approved by the FDA.2
Port delivery system
The size of a single grain of rice, this implantable device stores anti-VEGF drugs directly into the eye. The port delivery system (PDS) is placed during surgery and may allow up to 2 years of medicine delivery. Refills of the device may occur in a doctor’s office. Still in clinical trial, the PDS device may be available for the treatment of wet AMD within 3 years.2
