Emerging Treatments for Dry macular Degeneration by: Adam AufderHeide, MD, PhD

Age-Related Macular Degeneration (AMD) is an eye disease found in people over the age of 50. Patients describe blurring or loss of central vision. This is due to the disease affecting the macula which is the central part of the retina. The retina is the light sensitive portion of eye. In people with macular degeneration, one of the earliest signs is the formation of drusen. Drusen form underneath the retina and are composed of debris made of proteins and fats that the body does not adequately clear. As macular degeneration progresses, there are two primary forms of vision loss. In nonexudative Macular Degeneration (also known as dry macular degeneration), geographic atrophy of the retina can occur. Geographic atrophy is an advanced form of degeneration caused by dry AMD that can lead to profound vision loss. In exudative macular degeneration (also known as wet macular degeneration), new blood vessels begin to grow and replace healthy retina with scar tissue. For many years, we’ve had medications, known as antiVEGFs, to treat wet macular degeneration by making the new blood vessels regress. Unfortunately, the treatment for dry macular degeneration, specifically the geographic atrophy that causes such profound vision loss has been untreatable, and even in wet AMD, geographic atrophy can still occur.

There are numerous risk factors development of geographic atrophy of macular degeneration. These include age (60+), family history (genetics is estimated to contribute approximately 70% of the role in GA development), diet high in fatty foods and cholesterol, high blood pressure, history of smoking, low physical activity, and obesity. Symptoms that patients typically notice is hazy or blurred vision, straight lines appear wavy or crooked, increased difficulty seeing in low light, a growing blurry spot in the center of their vision and colors seem dull or washed out.

The lack of therapy to treat progression of dry AMD represents a significant unmet need considering its effect on vision and the number of people affected. Estimates have suggested that there are approximately 1 million people in the US with geographic atrophy causing vision loss and approximately 5 million people worldwide.

Luckily, with such a need, a great deal of research has gone into strategies for reducing vision loss due to dry AMD. These include neuroprotection, reducing oxidative stress and reducing the accumulation of toxic byproducts of vision, use of stem cell therapy, and perhaps most exciting, suppressing inflammation. Ongoing research has suggested that GA may be caused by an overaction of part of the immune system. This leads to inflammation which contributes to the body destroying healthy cells in the retina. While this damage may start small, the cells continue to die off and form larger patches that can spread across the retina. Two new treatments are currently undergoing advanced clinical trials and may be available commercially soon. These target the complement system, binding to components of the system and inactivating them. The results seem to be promising in slowing or halting the progression of geographic atrophy.

If you have macular degeneration, you should talk to your retina specialist about these new medications and if they might be appropriate for you.