A leading cause of blindness
Diabetic retinopathy is the most common diabetic eye disease and a leading cause of blindness in American adults. It is caused by changes in the blood vessels of the retina – the light-sensitive tissue at the back of the eye necessary for good vision. In some people with diabetic retinopathy, retinal blood vessels may leak fluid and cause swelling of the retina in the macular region, which adversely affects central vision. In other people, abnormal new blood vessels grow on the surface of the retina and can cause severe bleeding into the eye. If you have diabetic retinopathy, at first you may not notice changes to your vision. But over time, diabetic retinopathy can get worse and cause vision loss. Diabetic retinopathy usually affects both eyes.
The Stages of Diabetic Retinopathy
Diabetic retinopathy has four stages:
- Mild Nonproliferative Retinopathy. At this earliest stage, micro-aneurysms occur. They are small areas of balloon-like swelling in the retina's tiny blood vessels.
- Moderate Nonproliferative Retinopathy. As the disease progresses, some blood vessels that nourish the retina are blocked.
- Severe Nonproliferative Retinopathy. Many more blood vessels are blocked, depriving several areas of the retina with their blood supply. These areas of the retina send signals to the body to grow new blood vessels for nourishment.
- Proliferative Retinopathy. At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels. This condition is called proliferative retinopathy. These new blood vessels are abnormal and fragile. They grow along the retina and along the back surface of the clear, vitreous gel that fills the inside of the eye. By themselves, these blood vessels do not cause symptoms or vision loss. However, they have thin, fragile walls. If they leak blood, severe vision loss and even blindness can result.
Often there are no symptoms in the early stages of the disease, nor is there any pain. Don't wait for symptoms. Be sure to have a comprehensive dilated eye exam at least once a year.
Blurred vision may occur when the macula – the part of the retina that provides sharp central vision – swells from leaking fluid. This condition is called macular edema. If new blood vessels grow on the surface of the retina, they can bleed into the eye and block vision. At first, you will see a few specks of blood, or spots, "floating" in your vision. If spots occur, see your eye care professional as soon as possible. You may need treatment before more serious bleeding occurs. Hemorrhages tend to happen more than once, often during sleep. If left untreated, proliferative retinopathy can cause severe vision loss and even blindness. Also, the earlier you receive treatment, the more likely treatment will be effective.
Treatment for Diabetic Retinopathy
During the first three stages of diabetic retinopathy, no treatment is needed, unless you have macular edema. To prevent progression of diabetic retinopathy, people with diabetes should control their levels of blood sugar, blood pressure and blood cholesterol.
Proliferative diabetic retinopathy is treated with laser surgery. At the Irwin Retina Center, laser surgery is done as an outpatient procedure and requires no surgical incision. A strong light beam is aimed onto the retina to treat and shrink the abnormal vessels. If the bleeding is severe, you may need a surgical procedure called a vitrectomy. During a vitrectomy, blood is removed from the center of the eye.
If you have macular edema, laser surgery may also be used. In this case, the laser beam is used to seal the leaking blood vessels. If you have macular edema in both eyes and require laser surgery, generally only one eye will be treated at a time, usually several weeks apart. Focal laser treatment stabilizes vision. In fact, laser treatment reduces the risk of vision loss by 50 percent. In a small number of cases, if vision is lost, it can be improved.
Research has shown that prompt treatment of macular edema with the drug Lucentis, with or without laser treatment, resulted in better vision than laser treatment alone or steroid injections. When injected into the eye, Lucentis – and two other similar drugs, Avastin and Eylea – reduce fluid leakage and interfere with the growth of new blood vessels in the retina. Your doctor will help you decide what is best for you.
Finding diabetic retinopathy early is the best way to prevent vision loss. With timely treatment, the majority of those with advanced diabetic retinopathy can be saved from going blind.
Other Retinal Disorders
The Irwin Retina Center also offers diagnosis and treatment for other diseases and disorders of the retina, including:
- Retinal detachment. Retinal detachment is a medical emergency requiring prompt surgical treatment to preserve vision. The retina is the light-sensitive tissue that lines the inside back wall of your eye. In retinal detachment, the retina is pulled away from the underlying choroid — a thin layer of blood vessels that supplies oxygen and nutrients to the retina. Retinal detachment leaves retinal cells deprived of oxygen. The longer the retina and choroid remain separated, the greater the risk of permanent vision loss in the affected eye. Fortunately, retinal detachment often has clear warning signs. If you go to an ophthalmologist as soon as warning signs appear, early diagnosis and treatment of retinal detachment can save your vision.
- Retinal Vein Occlusions (RVO). Retina vein occlusions are the second-most common retinal vascular problem after diabetic retinopathy. RVO is a blockage of the small veins that carry blood away from the retina – the layer of tissue at the back of the inner eye that converts light images to nerve signals and sends them to the brain. RVO occurs more often in people with diabetes, glaucoma or hypertension. The Irwin Retina Center is a recognized leader in the treatment of this disorder. Treatments may include laser treatment and injections of special drugs that block the growth of new blood vessels.
- Uveitis. Uveitis is swelling and irritation of the uvea, the middle layer of the eye. Causes include allergy, infection, chemical exposure, trauma – or the cause may be unknown. Because it may be associated with more than 100 diseases, uveitis also serves as an indication of other medical problems. If left untreated, inflammation inside the eye can lead to blindness. If you suspect you have uveitis, consult an ophthalmologist at once.
- CMV Retinitis. Cytomegalovirus (CMV) is a viral inflammation of the retina of the eye and is caused by a member of the herpes simplex virus family. Mild CMV infections are common in otherwise healthy people but severe CMV disease is not. Your immune system usually keeps them from triggering an active disease. In someone with a weak immune system, it can cause CMV retinitis, an infection of the eye that can lead to blindness. If left untreated, CMV can spread throughout the body, infecting other organs to create a wide range of symptoms that can lead to serious illness, even blindness. The goal of treatment is to stabilize or restore vision and prevent blindness. Long-term treatment is often needed. Medications may be given by mouth, through a vein or injected directly into the eye. Treatments for CMV are effective if the infection is detected early.