Overview of Age-Related Macular Degeneration

Arshad Khanani, MD: Age-related macular degeneration [AMD] is 1 of the most common causes of vision loss. As a retina specialist, I see a lot of these patients daily. Advanced forms of AMD are seen primarily in 2 types: neovascular or wet AMD and non-neovascular or dry AMD. The hallmark of this disease is the presence of drusen in the macula, followed by changes in the RPE [retinal pigment epithelium] and Bruch membrane and photoreceptor loss. The progression of dry AMD happens over time, and concurrently you can also get wet AMD where you have neovascularization of the macula, leakage, and bleeding. When you look at the number of patients with specific types of AMD, 90% of patients have dry AMD vs 10% to 15% of patients with wet AMD, but the wet AMD accounts for almost 90% vision loss in patients with this condition.

Looking at patients with macular degeneration, the majority of them are in their 50s and 60s or older. Because this is an age-related disease, they may have signs of drusen or early dry age-related macular degeneration, which usually is asymptomatic. That’s why we prefer yearly eye exams for patients to evaluate their retina and to see if they have any macular degeneration going on. Most of that is done by the optometrist or general ophthalmologist. Most of the patients I see in my clinic will have intermediate or advanced macular degeneration, whether it’s dry or wet, and the majority of my patients have symptoms. This is usually a bilateral disease in terms of the dry component. The wet component usually shows up initially in 1 eye, but then they have a risk of having wet AMD in the other eye of about 10% per year. Most of these patients come in complaining of metamorphosis, which is distortion in the vision, or they come in with black spots or missing spots in their vision depending on whether they have leakage or bleeding, or they have the advanced form of dry macular degeneration called geographic atrophy.

When you look at patients with AMD, it has a significant impact on their quality of life, whether it’s reading small print, needing more light, or needing higher magnification. They also have difficulty driving if they have central involvement or if they don’t qualify to drive based on the vision loss. They also have issues with color and contrast. It can really impact their life in a negative way where they can lose their independence, especially if you have an older person living alone. They cannot take care of themselves because of poor vision. That’s why our job as retina specialists is to treat these patients on time and continue to innovate to come up with better treatments for this blinding condition.

There have been some early studies talking about Alzheimer’s disease and the association with age-related macular degeneration. Of course, the data is early. We need more studies to have a good correlation. You know that both diseases are age related and they can concurrently happen in patients. I’m looking forward to learning more about any association between Alzheimer’s and age-related macular degeneration. At this point, I think there is early evidence that there may be some correlation, but we are not sure yet, so we’ll continue to look at bigger and more trials.

Transcript Edited for Clarity