The macula is a part of the retina in the back of the eye that ensures that our central vision is clear and sharp. Age-related macular degeneration (AMD) occurs when the arteries that nourish the retina harden. Deprived of nutrients, the retinal tissues begin to weaken and die, causing vision loss. Patients may experience anything from a blurry, gray or distorted area to a blind spot in the center of vision.
AMD is the number-one cause of vision loss in the U.S. Macular degeneration doesn't cause total blindness because it doesn't affect the peripheral vision. Possible risk factors include genetics, age, diet, smoking and sunlight exposure. Regular eye exams are highly recommended to detect macular degeneration early and prevent permanent vision loss.
Symptoms of macular degeneration include:
There are two kinds of AMD: wet (neovascular/exudative) and dry (non-neovascular). About 10-15% of people with AMD have the wet form. "Neovascular" means "new vessels." Accordingly, wet AMD occurs when new blood vessels grow into the retina as the eye attempts to compensate for the blocked arteries. These new vessels are very fragile, and often leak blood and fluid between the layers of the retina. Not only does this leakage distort vision, but when the blood dries, scar tissue forms on the retina as well. This creates a dark spot in the patient's vision.
Dry AMD is much more common than wet AMD. Patients with this type of macular degeneration do not experience new vessel growth. Instead, symptoms include thinning of the retina, loss of retinal pigment and the formation of small, round particles inside the retina called drusen. Vision loss with dry AMD is slower and often less severe than with wet AMD.
Recent developments in ophthalmology allow doctors to treat many patients with early-stage AMD with the help of lasers and medication.
Patients with diabetes are at a higher risk for developing eye conditions because a high blood sugar level can damage blood vessels in the eye. Over 40 percent of patients diagnosed with diabetes develop some form of eye disease as a result. These conditions can cause blood or fluid to leak from the retina or new blood vessels to grow on the surface of the retina, which can lead to significant damages to your vision and overall quality of life.
It is important for patients with diabetes to have dilated eye exams once a year to detect any signs of diabetic eye disease as soon as possible. You can also minimize your risk of developing diabetic eye disease by keeping your blood sugar and blood pressure under control, eating a healthy diet and exercising regularly.
Your eyes can be affected by several different eye diseases related to diabetes. Some of these conditions include:
Diabetic retinopathy is a complication of diabetes that weakens the blood vessels that supply nourishment to the retina (the light-sensitive lining in the back of the eye where vision is focused). These weak vessels can leak, swell or develop thin branches, causing a loss of vision. Changes to your vision may not be noticeable at first. But in its advanced stages, the disease can cause blurred or cloudy vision, floaters and blind spots – and, eventually, blindness. This damage is irreversible. Diabetic retinopathy is the most common diabetic eye complication and a leading cause of blindness in American adults. Macular edema, which is leaking fluid that causes blurred vision, often occurs with diabetic retinopathy.
Fortunately, diabetic retinopathy is preventable. People with diabetes are most susceptible to developing it, but your risk is reduced if you follow your prescribed diet and medications, exercise regularly, control your blood pressure, and avoid alcohol and cigarettes. Regular eye exams are an integral part of making sure your eyes are healthy. Diabetic retinopathy can be detected through a visual acuity test, a dilated eye exam or tonometry.
Although damage caused by diabetic retinopathy cannot be corrected, patients diagnosed with the condition can be treated to slow its progression and prevent further vision loss. Treatment modalities include laser and surgical procedures.
A retinal vein occlusion occurs when an artery supplying blood to the eye hardens or swells and presses on a nearby vein and blocks it, making it difficult for blood to leave the eye. The restricted circulation leads to high pressure in the eye, which can in turn cause swelling, bleeding, growth of abnormal blood vessels, and partial or total vision loss.
Vascular occlusions do not cause a change in physical appearance, and they can occur with no pain or noticeable loss of vision. For these reasons, it is important to have routine eye exams and also to check one's own vision by closing one eye at a time.
There is no cure, so emphasis is placed on risk management, treatment of symptoms and prevention of further vision loss. It is critical to control high blood pressure, high cholesterol, diabetes and other health conditions that increase the risk of vascular hardening, narrowing and blood clotting.