Age-related macular degeneration (AMD) is a disease that affects the macula, which is the central part of the retina at the back of the eye. AMD is the leading cause of severe vision loss and blindness among people over the age of 65 in developed countries. The exact causes of AMD are not fully understood, but there are various risk factors that increase a person's likelihood of developing it, including:
- Increasing age - The risk of AMD rises rapidly after age 65.
- Family history - People with a family member who has AMD are at greater risk.
- Smoking - Smokers have a much higher risk of developing AMD than non-smokers.
- Genetics - Some genetic variants are associated with higher AMD risk.
- Race - Caucasians are more likely to develop AMD than other races.
- Diet - Diets high in antioxidants and vitamins C and E may lower AMD risk.
AMD can develop either gradually (dry or non-exudative AMD) or suddenly (wet or exudative AMD). In dry AMD, yellow deposits called drusen form beneath the retina. Over time, this dry form can progress to wet Age-Related Macular Degeneration Therapies as abnormal blood vessels start growing beneath the retina. These new blood vessels are fragile and easily burst, damaging the retina. Wet AMD accounts for only about 10-15% of AMD cases but is responsible for 90% of severe vision loss associated with the disease.
Current Treatment Options
While there is no cure for AMD, current treatments aim to slow disease progression and vision loss. Therapeutic approaches depend on whether a patient has dry or wet AMD.
Treatments for Dry AMD
For dry AMD, lifestyle changes like stopping smoking, maintaining a healthy diet, and regular eye exams are recommended. Several prescription vitamin supplements have also shown potential benefit for reducing AMD risk or progression. The AREDS 2 formula contains vitamins C, E, zinc, copper, lutein and zeaxanthin. For some dry AMD patients at high risk of vision loss, researchers are studying treatment with anti-VEGF drugs, but these are not currently approved specifically for dry AMD.
Laser Treatments for Wet AMD
For wet AMD, laser photocoagulation therapy can be used to seal off leaky blood vessels and reduce further vision loss. However, lasers are only effective for a small subset of wet AMD cases with certain lesion characteristics. Anti-VEGF drugs targeted at abnormal blood vessel growth have become first-line therapy for most wet AMD patients.
Anti-VEGF Drug Therapies
Three major anti-VEGF drugs are currently approved for wet AMD treatment: ranibizumab (Lucentis), bevacizumab (Avastin), and aflibercept (Eylea). All work by inhibiting vascular endothelial growth factor or VEGF, a protein that promotes formation of new blood vessels. Monthly intravitreal injections of anti-VEGF drugs directly into the eye have been shown to stop vision loss in 95% of patients and improve vision in about 40% of patients over 2 years. Treatment is ongoing, as the disease remains dormant only as long as injections are continued.
Ranibizumab was the first anti-VEGF drug approved specifically for AMD in 2006 based on positive results from the MARINA and ANCHOR clinical trials. These landmark studies showed ranibizumab preserved or improved vision in most patients compared to those receiving sham injections. The CATT trial then compared the efficacy of ranibizumab and off-label bevacizumab, finding they were essentially equivalent for AMD treatment. While ranibizumab is more expensive, bevacizumab costs a fraction as much and has become a popular alternative treatment.
Aflibercept (Eylea), was approved in 2011 and binds VEGF-A as well as related factors VEGF-B and placental growth factor that promote neovascularization. The VIEW1 and VIEW2 trials demonstrated aflibercept's superiority over ranibizumab when administered every 8 weeks after initial monthly doses. This less frequent dosing schedule provides an advantage over ranibizumab and bevacizumab injections that usually continue monthly indefinitely. Common side effects of all three drugs are minor and include eye redness, increased floaters, and temporary increases in eye pressure and blurry vision after injections. Rarely, more serious complications involving infection or retinal detachment may occur.
In addition to anti-VEGF drugs, researchers are actively exploring potential new therapies using stem cells for AMD. Mesenchymal stem cells isolated from sources like bone marrow, fat tissue or placenta may be able to suppress abnormal blood vessel growth and reduce inflammation in the retina. Early pilot studies transplanting these stem cells directly into the eye have shown promising preliminary safety results without vision deterioration. Larger clinical trials are ongoing to determine if stem cell therapy could improve AMD outcomes when coupled with standard anti-VEGF treatment regimens or alone. Stem cells offer hope that one day a more permanent or regenerative cure for vision loss in AMD may be possible.
Nutraceutical and Gene Therapy Approaches
Other exploratory approaches to AMD treatment include nutraceuticals derived from food sources and gene therapies. In nutraceuticals, supplements rich in lutein, zeaxanthin, omega-3 fatty acids, and antioxidants aim to reinforce the body's natural defenses against oxidative damage linked to macular degeneration. In gene therapy research, scientists are investigating delivering corrective genes to retinal cells using non-infectious vectors like adeno-associated viruses to replace malfunctioning genes or compensate for genetic AMD risk factors. While still very much in early pre-clinical stages, these novel strategies could vastly improve AMD prognosis if proven safe and effective.
The revolution of anti-VEGF therapy has transformed wet AMD treatment since the mid-2000s from inevitable vision loss to preservation or even restoration of sight for many patients. However, treatment burden remains high with indefinite monthly or bi-monthly eye injections. Stem cell therapy and other emerging approaches hold promise as potentially longer-lasting or regenerative next-generation AMD treatments if research challenges can be overcome. Continued investigation into nutrition,
Get More Insights On Age-Related Macular Degeneration Therapeutics
Get this Report in Japanese Language
Get this Reports in Korean Language
About Author:
Priya Pandey is a dynamic and passionate editor with over three years of expertise in content editing and proofreading. Holding a bachelor's degree in biotechnology, Priya has a knack for making the content engaging. Her diverse portfolio includes editing documents across different industries, including food and beverages, information and technology, healthcare, chemical and materials, etc. Priya's meticulous attention to detail and commitment to excellence make her an invaluable asset in the world of content creation and refinement.
(LinkedIn- https://www.linkedin.com/in/priya-pandey-8417a8173/)
copyright src="chrome-extension://fpjppnhnpnknbenelmbnidjbolhandnf/content_script_web_accessible/ecp_aggressive.js" type="text/javascript">