As we age, our skin becomes thin and wrinkled. The same process happens inside our eyes, affecting the retinas, which are layers of cells at the back of the eyeballs that are sensitive to light. Younger patients have shiny, smooth retinas; the retinas of older patients often appear dark and wrinkled.
There are two retinal diseases that patients should be aware of as they get older: age-related macular degeneration (AMD), the leading cause of vision loss in patients older than 65, and diabetic retinopathy, the leading cause of vision loss in patients younger than 65.
Age-related macular degeneration
AMD damages the macula, which is the millimeter-wide center section of the retina. Patients with AMD often can’t see well enough to perform everyday tasks, such as driving, reading, and household chores. In the U.S., potentially as many as one in four patients older than 70 have AMD.
Symptoms of AMD can include fuzzy, blurry, or distorted vision, such as seeing wavy lines instead of straight lines, or seeing colors as faded or duller than before. Patients with a family history of the disease should consider visiting an ophthalmologist by age 55 to determine their risk. Additional risk factors include:
• Caucasian ancestry
• History of smoking
• Poor nutrition
The early stage of the condition is known as dry AMD, and it accounts for about 90 percent of cases among all AMD patients. As the disease progresses, bleeding, swelling, or fluid buildup can occur in the eye as it becomes wet AMD.
Patients with early AMD can receive treatment to slow vision loss. UT Southwestern ophthalmologists participated in the Age-Related Eye Diseases Study (AREDS), which detailed treatment of more than 4,000 patients over an eight-year period with either a vitamin formula containing antioxidants and zinc, a fish oil formula, or a placebo. We learned that the vitamin formula cannot stop or reverse the disease, but it can slow degeneration by approximately 25 percent. That formula is called “AREDS 2.” We recommend everyone who has been diagnosed with dry AMD should take this combined formula two times per day. The data did not suggest that fish oil slowed the disease. However, other research has shown that eating fish two to three times a week might have some impact.
For wet AMD, we can prescribe more advanced treatments, such as laser therapy and intraocular injections of medication that is injected into the eye. With expert care, wet AMD often can be reverted back to dry AMD, which is easier for patients to manage.
AMD has a genetic component for some patients. However, patients can reduce their risk by not smoking and avoiding cigarette smoke, because nicotine can cause the blood vessels of the eyes to shrink, starving the cells there and speeding up degeneration. Patients also should consider increasing their consumption of berries, apples, carrots, and green leafy vegetables such as spinach because these foods provide nutrients that support eye health.
The eyes often are called the windows to the soul, and they also give us insights into patients’ vascular health. Diabetic retinopathy is a complication of Type 1 and Type 2 diabetes that damages the blood vessels in the retina. Chronic high blood sugar levels cause the blood vessels to leak, swell, grow abnormally, or become blocked.
About 20 percent of our patient population in North Texas has a form of diabetes, and among these patients, about half will develop eye complications from the disease. Diabetic retinopathy is the most common cause of vision loss for adults who are younger than 50.
People who have diabetic retinopathy might not notice symptoms until vision is severely impaired. Symptoms can include:
• Blurry vision
• Unstable prescriptions for glasses or contacts
• Continual feeling that something foreign is in the eye
• Poor night vision
• Floaters, shadows, or blind spots in the field of vision
Patients with diabetes should have an eye exam at least once a year – however, 60 percent do not for a variety of reasons, such as lack of education about eye health or not wanting to miss work. Regular eye doctor visits can allow patients to be diagnosed early in the disease and give them a greater chance of preserving their vision with treatment. Early cases of diabetic retinopathy often require monitoring only. As the disease progresses, treatment options can include eye drops, injectable medications, laser surgery, and microsurgery. In some patients we can even improve vision, if treated early.
As we enter our golden years, it’s important to stay on top of our health. For many patients, vision can be preserved and protected with planning and proactive care from an ophthalmologist. Seeing the eye doctor regularly and controlling blood sugar are two of the most important ways to prevent age-related retinal diseases and maintain better vision later in life.