Early detection key in thwarting macular degeneration

Macular degeneration, which can impair vision, is common in older people. But there are treatments for the disease, particularly if problems are caught early, said Dr. R. Ross Lakhanpal from MedStar Union Memorial Hospital Eye Center. He stressed the importance of regular eye exams because there may be no symptoms in the early stages of disease. Also, he said to see the doctor when there are unexplained changes.

What is macular degeneration and what are the different kinds?

Macular degeneration, the leading cause of vision loss in people over the age of 60, affects more than 10 million Americans. A common eye disease affecting the retina, macular degeneration is caused by the deterioration of the macula, the central portion of the retina, the inside back layer of the eye that records the images we see and sends them via the optic nerve from the eye to the brain. The macula is responsible for focusing central vision in the eye, which controls our ability to read, drive a car and recognize faces and colors. In macular degeneration, cells in the macular region begin to die, resulting in blind spots and distorted vision.

There are two forms of macular degeneration: dry and wet.

The most common, the dry form affects approximately 90 percent of all people with macular degeneration. It is characterized by the presence of yellow deposits, called drusen, in the macula. As the deposits increase in size and number, they lead to the distortion of vision. As the degeneration advances, the light-sensitive cells of the macula slowly break down, getting progressively thinner and functioning less and less. Known as atrophy, this progression causes patients to experience blind spots in the center of their vision.

Approximately 10 percent of all cases of macular degeneration progress to the wet form. The wet form of macular degeneration is characterized by the growth of abnormal blood vessels in the choroid layer behind the retina. These blood vessels leak blood and fluid into the retina, causing scar tissue to form and retinal cells to stop functioning, leading to permanent loss of central vision.

It is possible for a person to suffer from both forms of macular degeneration. Typically, a person has dry macular degeneration first, eventually advancing to wet. It is possible for the disease to affect only one or both eyes, and the speed of progression varies for many.

What are the symptoms and how is it diagnosed?

In the early stages of macular degeneration, there may be no symptoms. As the disease progresses, patients may experience blurred or fuzzy vision, the distortion of straight lines, the appearance of a dark or empty area in the center of the visual field, and sometimes a changed color perception.

If vision changes are occurring in the eye, do not ignore them; have your eyes checked by an ophthalmologist. A series of comprehensive tests can be performed to diagnose macular degeneration. A routine eye exam can detect early signs of the disease. Dilation of the pupils allows the ophthalmologist to effectively study the retina for signs of disease, including the presence of drusen, one of the most common early signs of macular degeneration.

An Amsler grid, a pattern of straight lines that resembles graph paper, is typically used to determine the distortion of straight lines. The Amsler grid is also a useful tool for at home monitoring.

If your ophthalmologist detects macular degeneration, a non-invasive technique, called an optical coherence tomography (OCT), may be used to image the retina. Using magnified 3-D images, layers and thickness are measured to identify regions of the retina that are thinning or that have macular swelling from wet AMD.

In addition, a procedure call fluorescein angiography may be performed to detect leaking blood vessels. During this procedure, dye is injected into a vein in the arm. As the dye reaches the blood vessels in the retina, the presence of leakage or blood in the macula will be revealed.

Can macular degeneration be prevented?

Macular degeneration cannot be prevented, but you can reduce your risk by adopting these healthy lifestyle changes: maintain a healthy weight; exercise regularly; avoid smoking; eat a balanced diet that includes leafy green vegetables, eggs, fish, whole grains, and fruits abundant in vitamin C; maintain normal blood pressure and cholesterol levels; and protect your eyes from ultraviolet sun rays by wearing sunglasses.

Most importantly, be sure to get regular eye exams, and consult your doctor immediately if you any notice changes in vision.

How is it related to or complicated by other eye diseases?

At this time there is no firm evidence that other eye surgery adversely affects the choroidal circulation, but I prefer to see AMD patients before and immediately after eye surgery to ensure they do not progress to wet AMD.

What are the treatments and how effective are they?

There is currently no known cure for macular degeneration. However, early detection of macular degeneration is very important because there are treatments that can prevent severe vision loss or slow the progression of the disease. Vitamins are also found to be very effective in delaying and possibly preventing vision loss. The National Eye Institute’s Age-Related Eye Disease Study (AREDS 2) found that taking nutritional supplements with a specific high-dose formulation of antioxidants (vitamins C and E and Lutein and Zeaxanthin) delayed or prevented the progression of macular degeneration from the intermediate to the advanced stage.

Laser therapy and photodynamic laser therapy, are treatments often used to destroy actively growing abnormal blood vessels or seal off new blood vessels to prevent leakage that occurs in macular degeneration, but these are now not used often if the wet AMD is central.

Anti-angiogenic drugs, drugs that are injected into the eye, decrease macular swelling and also decrease the abnormal vascular component of wet AMD, and these are currently the primary therapy used. These injections have allowed many patients to regain lost vision. Injected into the eye, these medications block the development of new blood vessels and leakage from the abnormal vessels within the eye that cause macular degeneration.

Want to learn more about your risks? See one of our doctors at Eyecare Associates of Lee’s Summit. Schedule an appointment online or call or text the office at 816-524-8900.