Geographic atrophy (GA) represents an advanced stage of dry age-related macular degeneration (AMD), a progressive eye condition affecting the macula, the central part of the retina. This condition leads to the gradual degeneration and death of light-sensing cells and supporting tissue in the macula, resulting in irreversible central vision loss. Individuals with GA may experience blurry or blind spots in their central vision, making activities such as reading, driving, and recognizing faces increasingly difficult.
Approved Medical Interventions
Two complement inhibitors, pegcetacoplan (Syfovre) and avacincaptad pegol (Izervay), received FDA approval in 2023 for treating geographic atrophy. These medications target specific components of the complement system, an immune system part involved in GA progression. The complement system, while normally protecting the body, can become overactive in GA, leading to inflammation and damage to retinal cells.
Pegcetacoplan works by inhibiting complement factor 3 (C3), a central protein in the complement cascade. By blocking C3, pegcetacoplan aims to reduce destructive inflammation and cell death in the retina. Avacincaptad pegol specifically inhibits complement C5, preventing its cleavage and the formation of the membrane attack complex, a key component in cell destruction.
Both medications are administered through intravitreal injections, meaning they are injected directly into the eye, typically on a monthly or every-other-month basis. Clinical trials have shown that these treatments can slow the rate of GA lesion growth. Avacincaptad pegol demonstrated a significant reduction in GA growth rate, with some studies reporting up to a 35% reduction in progression over 12 months.
Despite their benefits in slowing disease progression, these treatments do not restore lost vision. Common side effects include eye pain, blurred vision, and conjunctival hemorrhage. There is also an increased risk of developing wet AMD, a different form of macular degeneration involving abnormal blood vessel growth, leading to further vision loss and requiring additional treatment.
More serious, less common side effects include intraocular inflammation, endophthalmitis, and retinal vasculitis, which can cause severe vision loss. Patients considering these treatments should discuss the potential benefits and risks with their ophthalmologist.
Emerging Therapies and Clinical Trials
Numerous therapies are currently under investigation in clinical trials for GA. These emerging approaches aim to further slow disease progression, and in some cases, potentially restore vision. Researchers are exploring strategies beyond complement inhibition, including gene therapies, neuroprotective agents, and stem cell therapies.
Other complement pathway inhibitors are being developed, targeting different points in the cascade for improved efficacy or safety. Gene therapies are exploring ways to deliver genetic material to the eye, instructing cells to produce proteins that can inhibit complement activation or protect retinal cells.
Neuroprotective agents focus on preserving the health of existing retinal cells. Stem cell therapies involve transplanting healthy cells into the macula to replace those lost due to GA. These treatments hold promise for addressing GA.
Participation in clinical trials offers patients access to these cutting-edge therapies before they are widely available, while also contributing to scientific advancements. These therapies are still in the experimental stages. Their long-term efficacy and safety are being evaluated, and there is no guarantee they will ultimately receive regulatory approval.
Holistic Management and Support
Beyond medical interventions, managing geographic atrophy includes supportive measures. Low vision aids can significantly assist individuals in navigating tasks affected by central vision loss. These include magnifiers, telescopic lenses, and electronic vision aids that enlarge text and images, making reading and other detailed activities more accessible.
Vision rehabilitation services and occupational therapy play a significant role in helping individuals adapt to their changing vision. These programs provide training on adaptive techniques and assistive technology, enabling patients to maintain independence in their daily routines. Occupational therapists can offer personalized strategies for tasks like cooking, managing medications, and using digital devices.
Lifestyle considerations can contribute to overall eye health, although they do not prevent or reverse GA progression. Maintaining a healthy diet rich in antioxidants and omega-3s, quitting smoking, and protecting eyes from UV radiation are recommended. Regular dilated eye exams are important for monitoring GA progression and discussing any new symptoms with an eye care professional.
Living with vision loss can present emotional challenges, and support systems are available to help individuals cope. Connecting with family and friends, seeking counseling, and joining support groups provide community and reduce isolation. These groups offer sharing experiences, learning coping strategies, and accessing valuable resources.