According to Prevent Blindness America, the number of people affected by the eye problems that are the leading causes of blindness will double. By the year 2030, twice as many people will be blind as are today.
Robert Mullins PhD, associate professor in the Department of Ophthalmology and Visual Sciences with University of Iowa Health Care, talks about preventing and treating eye problems that cause blindness:
What are some of the leading causes of blindness in America today?
Cataracts, age-related macular degeneration, glaucoma, and diabetic eye disease, called diabetic retinopathy are some very common conditions. Macular degeneration is actually very common, affecting one third or more of the older population.
Is there a certain population that is more likely to become blind?
For most of the common eye diseases, age is a risk factor. So the older population is at higher risk for many of these diseases. Vision loss is a serious issue with the aging population. You know, 100 years ago, the average life expectancy was under 50 and today it's close to 80. So we're living longer, which is good, but we're also susceptible to some diseases that didn't affect earlier generations. Apart from aging, certain ethnic groups are at higher risk for some kinds of eye disease. Macular degeneration is more common in Americans of European descent, and glaucoma is more common in Americans of African decent. So there is clearly a strong genetic component to these diseases.
Can blindness be prevented in some cases?
Certainly there are things that people can do to reduce the risk of losing their vision. Although it sounds pretty obvious, if you're doing something like using power tools or jump-starting a car, wearing goggles will help protect against eye injuries.
For patients with diabetes, controlling blood glucose is necessary to avoid complications in the retina. Getting your eyes checked periodically is recommended to look for risk of eye disease, things like increased pressure in the eye. People who experience a sudden loss in vision should see an eye doctor immediately.
One thing that can actually reduce the risk of some eye diseases, is quitting smoking. A number of studies have found that for macular degeneration, smokers can have an approximately doubled risk of getting the disease, compared to non-smokers. There's also some good news there, though, which is that the higher risk is for current smokers, not for past smokers. After a period of time after quitting smoking, former smokers return their risk of macular degeneration to about the same level as that of people who have never smoked. So at least for macular degeneration, if you're a current smoker, there's still time to reduce your risk if you quit now.
Can blindness be treated or cured and vision restored?
For some conditions, like cataracts, surgery can restore sight. In a patient with a cataract, the lens of the eye becomes opaque and stops transmitting light back to the retina. So the lens can be surgically replaced with an artificial one. There are a number of conditions that affect the retina that lead to death of the rods and cones, the cells that detect light. Rods and cones are like other nerve cells, and we're born with the number that we'll have for our entire life. The body doesn't have a way to replace them once they're lost.
There are some experimental treatments scientists are working on that offer promise for either replacing the lost nerve cells or using things like artificial implants that can detect light. So there is a lot of potential in these experimental treatments, but we still have a lot of work to do.
What is your particular area of interest with relationship to blindness?
Our laboratory works on a number of diseases of the retina, especially age-related macular degeneration.
What are you looking for in your research with regard to macular degeneration and blindness?
We're especially interested in a tissue called the choroid, which is a layer of blood vessels beneath the retina. The choroid provides the photosensitive retinal cells with oxygen, nutrients, and growth factors. The choroid is essential to the health of the retina, but in some patients abnormal blood vessels grow from the choroid and into the retina where they don't belong. These abnormal vessels can seriously damage the retina. So on one hand, normal blood vessels are key to the health of the retina, but on the other hand, in some eye conditions they can grow out of control and lead to loss of vision. So there's a balance—too few vessels cause damage to the retina because it doesn't receive the nourishment that it needs; but if there are too many vessels, or if the vessels grow into the wrong place, that also damages the retina.
In spite of the importance of these blood vessels, relatively little is known about what triggers them to grow during disease.
In my laboratory, we study the cells in these blood vessels from human donor eyes. Most animals we use in research don't develop the types of changes that occur in human eyes with macular degeneration. Because of this, studying eyes from human donors is essential for really grasping how diseases like macular degeneration occur. So we're very grateful to the Iowa Lions Eye Bank and to the eye donors and their families who enable us to understand macular degeneration and other diseases. It's certainly our hope that the information we obtain from these samples will benefit patients in the future. |
