In this MD Newsline exclusive interview with vitreoretinal specialist Dr. Alan Franklin, we discuss risk factors for wet AMD.
MD Newsline:
Is there a genetic basis for why Caucasian Americans and Chinese Americans seem to suffer more from wet AMD?
Dr. Alan Franklin:
“There is definitely a genetic basis for AMD. For wet AMD, there are a couple of genes that have been implicated. Caucasians and even Chinese people are thought to suffer more from wet AMD because they have less pigment in their retinal pigment epithelium (RPE). As a result, their RPE ultimately offers less protection from the formation of abnormal vessels in the choroid, which leak and bleed, damaging the macula.
In contrast, more darkly pigmented people seem to be more susceptible to a condition known as polypoidal choroidal vasculopathy, where they get little tiny growths of vessels, but the RPE envelops them, and they don’t have a whole lot of fluid leakage, though a few unlucky people do have bleeding.”
MD Newsline:
Why do you think, on average, more women than men are affected by wet AMD?
Dr. Alan Franklin:
“We don’t have a clear answer as to why more women than men are affected by wet AMD. The prevalence between men and women for AMD, in general, is pretty similar, but women do have a little higher risk for wet AMD. Looking at some of the genes involved with AMD, some genes are more male-specific, and some are more female-specific. So, the answer probably has something to do with the more female-specific genetic wobbles.”
MD Newsline:
Are there lifestyle and environmental factors that increase one’s risk of developing wet AMD?
Dr. Alan Franklin:
“In addition to genetics, lifestyle factors also contribute to the development of AMD. For example, smoking has been shown to make macular degeneration worse. We know that on a molecular level, smoking downregulates a protective gene for macular degeneration.
And, we’re pretty visual creatures. About 50% of the brain is devoted to the visual system. So, sometimes, patients won’t listen to their general practitioner when they tell them to stop smoking. But, when they’re facing blindness, that’s often the stimulus that gets patients to stop smoking.
Finally, prolonged, unprotected UV exposure probably does play a role in the development of AMD as well.”
MD Newsline:
Is there anything that we didn’t cover that you feel would be important for our physician audience to know about AMD or wet AMD?
Dr. Alan Franklin:
“Another lifestyle factor that impacts AMD is one’s consumption of green leafy vegetables and fruits that contain lutein and zeaxanthin, which make up macular pigment. When you look at the age-related eye disease study (AREDS), it supports the consumption of vitamin C, vitamin E, zinc, copper, lutein, and zeaxanthin to delay the progression of intermediate and advanced AMD. So, I’ll tell folks, you can take the AREDS vitamin, or you can have a diet high in fruits and vegetables.
However, for people with early AMD or without AMD, the AREDS study doesn’t support this lifestyle modification, as there was absolutely no benefit from it over a 6-year timeframe.”
Responses have been condensed and lightly edited.
