Age-related macular degeneration (AMD)

What is age-related macular degeneration (AMD) and what are the different types?

Age-related macular degeneration (AMD) is the destruction and loss of the photoreceptors in the macular (central) region of the retina resulting in decreased central vision and, in advanced cases, blindness.

Individuals at higher risk for AMD are above 50 years old, have a family history of AMD, are smokers, or have a poor diet.

There are two main types of AMD:

Dry form

The early dry form is the default pathway for macular degeneration. Some patients will develop the more advanced form of drying macular degeneration—geographic atrophy— a condition that results in irreversible vision loss. It’s a rather slow process that does not have a cure.

Wet form

Someone could lose vision with macular degeneration through the wet form, also known as exudative age-related macular degeneration. Treatments for the wet form of age-related macular degeneration are available. A patient would experience vision loss quite rapidly.

What AMD-related research is taking place?

There’s a lot of research on preventing the end-stage of the dry or wet form. A multidisplinary team of clinicians, engineers, laboratory scientists, statisticians, and geneticists are looking to see how blood supply for the retina, specifically the choroid, is damaged in the early process of macular degeneration, and how that can lead to more concerning forms. We’re using sophisticated, state-of-the-art algorithm similar to artificial intelligence to look at individual layers of a patient’s retina. We compare a patient’s retina against a person without age-related macular degeneration to identify risk factors and some of the genetic factors that predispose someone to experience changes in their retina.

What research is taking place at the University of Iowa’s Institute for Vision Research?

Our primary goal is to treat patients with inherited retinal disease, regardless of whether it’s a rare cause like retinitis pigmentosa or something more common like age-related macular degeneration. For people with relatively early disease, we’ve found that gene therapy has a lot of promise but those with late phases of disease where a lot of cells have been lost, induced pluripotent stem cells can be used to replace cells. They are derived from that same patient corrected for their genetic mutation to deliver a treatment that will hopefully restore vision. The tools and knowledge that we gain from treating these rare, inherited diseases provide a foundation for treating patients with the more common form of macular degeneration and age-related macular degeneration.

What are the treatment options for AMD?

There are a couple of medicines that are very effective for treating the wet form. Patients have to receive the injections every four to six weeks. We’re looking at ways to deliver longer acting medicine or find medicines that can increase the duration of the medicine we currently have available. There’s going to be a lot of new medications that will be at least tested in clinical trials over the next couple years for the wet form of macular degeneration. For the dry form of macular degeneration, that’s all stuff we’re doing in the laboratory and clinical trials but there’s nothing out there at this time to treat someone with the dry form of macular degeneration. Hopefully the treatments we’re developing at the Institute for Vision Research to repair someone’s retina using their own cells, in this case, retinal cells derived from stem cells from, will be applicable to patients with age-related macular degeneration.

Last reviewed: 
July 2017

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