The choroid in aging and disease

Published on October 31, 2016   28 min
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Good day, my name is Robert Mullins, and I'm a professor of Ophthalmology and Visual Sciences at the University of Iowa. Today we're going to talk about the changes that occur in the choroid in aging and in macular disease.
The choroid has some normal physiological changes that occur during aging that are differentiated from those that occur in diseases, like macular degeneration. Some of the same events that occur during normal aging, however, can occur to a more profound extent in diseases, like age-related macular degeneration or AMD.
Age-related macular degeneration is a common form of blindness that affects millions in the Western world. And as its name implies, it is an age-related disease. It's normally not seen in individuals under the age of 55 or 60. It affects the macular specific region of the retina that's responsible for visual acuity. The macula itself is about only the size of a button on one's shirt, but in spite of the fact that it's a small portion of the retina, it's responsible for most of our daily vision. And it's a degenerative disease in which the photoreceptor cells will eventually succumb to loss through one of several mechanisms. We don't completely understand the pathogenesis of this disease. We do know that there are different phenotypes or what might be considered stages including early AMD, neovascular AMD, and atrophic AMD. And these stages are characterized by structural feature called drusen.
The next few slides will compare the fundus appearance on the left, with the histological appearance on the right, of different disease types in AMD. And I should say that the sections are not collected from the same photograph in each case, as the fundus picture. However, they do give a good comparison of what the histology looks like in each case. First is a normal eye, you can see the retinal circulation. The collateral circulation is masked largely by the RPE. And histologically, the ganglion cell layer, the inner nuclear layer, the outer nuclear layer are present. The RPE is present as a continuous layer, and the choriocapillaris, you can see as these white openings that correspond to healthy viable choriocapillaris vessels.