Regional
(2009-10-19)
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GREELEY, CO
(KUNC) -
A quick search of the internet search reveals numerous medical conditions associated with the eye. One in particular affects more than 1.7 million U-S residents currently and is expected to grow to 3 million over the next ten years. KUNC commentator Dr. Marc Ringel has more.
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"Macula" is Latin for small spot or stain. Most people know this word in the context of macular degeneration, the biggest cause of blindness among Americans over 65. The macula lutea is a small yellow spot on the retina, which gets its hue from pigments contained in the light-sensitive cones that are highly concentrated there.
The density of these colored-light receptors makes the macula lutea the highest acuity place in the back of the eyeball. When you focus your eyes on an object, near or far, you are adjusting your visual apparatus to throw the image right on the macula. Whether reading or driving, it's the maculae that pick up the richest images to send down the optic nerves for processing in your brain.
The central location of this piece of retinal real estate gives it a value way disproportionate to its small size. So, when the macula stops working it can be debilitating. Though there are strategies for making the best of whatever peripheral vision has been spared, people who lose their macula-dependent central vision may be impaired to the point of legal blindness.
We don't understand yet exactly what causes the macula to degenerate. Age is the biggest risk factor. One percent of people in their sixties have some degree of macular degeneration and fifteen percent of folks in their nineties do.
Caucasians and women get more than their share of macular degeneration. So do smokers, the overweight and the sedentary. A family history increases one's chances of getting the disease. High blood pressure is another risk factor.
It's still not been decided if exposure to bright sunlight over time is a cause. It is prudent to wear sunglasses anyway because shades definitely do help to prevent cataracts.
There are two forms of the disease, dry and wet. In the former, the retina just sort of thins out, dries up, and scars. High doses of vitamins A, C and E, as well as lutein, an anti-oxidant micronutrient, appear to slow progression. Sometimes dry macular degeneration proceeds to the more severe wet form.
In the latter type, which accounts for 10% of cases, abnormal little blood vessels grow under the retina, leak and bleed and wreak havoc on the sensitive visual receptors. It is the tendency for leaking to spread and to recur, progressively knocking out swaths of the retina, that makes this the scarier form of the disease.
Fortunately, there are treatments for wet macular degeneration. The old standby is called photodynamic therapy, which employs a laser beam shot through cornea, lens, and transparent jelly of the eyeball and onto the retina to zap abnormal new blood vessels before they can leak much. There is also a newer drug therapy based on antibodies that neutralize hormones which act locally in the retina to stimulate growth of blood vessels. These drugs are injected right into the eyeball.
Here's a summary of recommendations:
Get in the habit of wearing sunglasses in bright light.
Make an annual visit to an eye care professional, especially after the age of 60. Since there are things that can be done to slow the progression of macular degeneration, wet or dry, it's important to diagnose it early.
Eating foods that are high in the antioxidant vitamins A, C and E and lutein may help to prevent the disease. Or take a multivitamin that has these ingredients. You can get more detailed information on this subject from your primary care provider or eye doctor.
Control your blood pressure.
If you can help it, don't be born a white woman of parents who have macular
degeneration.
And the usual: don't smoke, stay active, and try to hold your weight down.
It just struck me that, no matter what medical problem I discuss, the advice seems to come out about the same: take care of yourself in general and seek professional medical help appropriately. Thank you for listening and pardon me if I'm starting to sound a little repetitive.
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