Macular Degeneration
What is macular degeneration?
The macula is the central area of the retina where reading vision is located. The retina is the light-sensitive inner lining in the back of the eye, similar to the film in a camera. The macula is located in the straight-ahead position of the eye and forms the center of the retina. If the retina were a target, the macula would be the bull’s eye.
Macular degeneration causes blurred, distorted, or dark vision in the center of your sight. While it rarely causes total blindness, it can make reading, driving, and recognizing faces difficult or impossible.
What causes age-related macular degeneration?
Macular degeneration most often occurs in older adults, though it can appear earlier in certain families. The risk increases with age and genetics, and is worsened by high blood pressure and smoking. It is the most common cause of legal blindness in older adults in the United States. There are two main forms: dry and wet.
What is the difference between wet and dry macular degeneration?
Most people have the dry form, which involves pigment changes and yellow deposits called drusen. You may need more light to read and take longer to adjust to darkness. Many people retain useful vision, but advanced dry AMD (called geographic atrophy) can cause legal blindness.
Geographic atrophy is a slow, irreversible loss of macular cells responsible for central vision. It affects about 20% of those with macular degeneration.
Wet macular degeneration affects 10–15% of patients and is more severe. Abnormal blood vessels grow and leak under the macula, causing bleeding and scarring that can quickly reduce vision. It can be classified into classic, occult, polypoid, and retinal angiomatous proliferation (RAP) types.
What are the symptoms of wet macular degeneration?
Dry macular degeneration progresses slowly and may go unnoticed at first. Detecting the transition to wet AMD early is critical for the best results. Symptoms may include dark areas or holes in central vision, blurred words while reading, or straight lines appearing wavy. A simple test to detect these changes is the Amsler grid.
Amsler Grid
Instructions for using the Amsler Grid:
- Use good lighting and hold the grid about one foot away while wearing your reading glasses if needed.
- Cover one eye. With the other, focus on the center dot of the grid.
- Note if any lines appear wavy, distorted, or if dark or blurry areas are visible.
- Repeat with the other eye.
- If you see changes, contact your eye doctor.
How is wet macular degeneration diagnosed?
Because symptoms often begin in one eye, good vision in the other may hide early warning signs. Regular use of the Amsler grid and annual eye exams help detect it early. Your eye doctor can examine your macula using special microscopes or imaging tests such as fluorescein angiography, indocyanine green angiography, and optical coherence tomography (OCT), which show leaking or abnormal blood vessels.
How is wet macular degeneration treated?
For most patients, anti-angiogenic injections are the main therapy. These medications block abnormal vessel growth and fluid leakage under the macula. FDA-approved drugs include Lucentis, Eylea, and Vabysmo. Avastin is used off-label and may be covered by some insurance plans.
Lucentis: Shown to maintain or improve vision in most patients, with monthly injections providing the best results.
Eylea: Works similarly to Lucentis and may allow for less frequent injections for some patients.
Vabysmo: Targets both VEGF and Angiopoietin-2, potentially reducing injection frequency. Retina Associates of Florida participated in its clinical trials.
Avastin: An off-label, lower-cost alternative. It is effective but compounded by pharmacies, which may increase contamination risks.
Biosimilar therapy: New medications similar to Lucentis and Eylea may be prescribed depending on insurance coverage.
Surgical device implantation: Susvimo, an implantable port delivery system, slowly releases medication over several months and can reduce the number of injections. Retina Associates of Florida was a participating site in clinical trials for this treatment.
New treatments on the horizon
Several promising developments include sustained-release injections (such as EYP-1901) and early-stage stem cell therapies aimed at replacing damaged retinal tissue.
What if I have a macular hemorrhage?
Small hemorrhages are usually treated with standard anti-VEGF injections. Larger ones may require a gas bubble or TPA injection to clear blood under the macula.
What about aspirin and other anticoagulants?
Blood thinners do not cause macular bleeding but may worsen the severity of a hemorrhage if one occurs. Always discuss risks and benefits with your doctor before changing medication use.
Treatments for dry macular degeneration
The National Eye Institute found that daily use of antioxidant vitamins (C, E, zinc, copper, lutein, and zeaxanthin—known as the AREDS2 formula) can reduce the risk of progression to wet AMD by 25%. Supplements such as Ocuvite, Preservision, and I-Caps AREDS2 follow this formula. Smokers should avoid formulations with vitamin A due to increased lung cancer risk.
Syfovre: A complement 3 inhibitor shown to slow the growth of geographic atrophy by 24%. Retina Associates of Florida participated in the clinical trials.
Izervay: A complement 5 inhibitor that reduces the rate of geographic atrophy progression by up to 28% in one year. Both Syfovre and Izervay offer new hope for patients with advanced dry AMD.
What if vision is reduced despite treatment?
Low vision aids can significantly improve visual ability for legally blind patients. Options include magnifiers, stronger lighting, and electronic devices such as CCTVs. Some implantable telescopic devices are also available for qualified patients.