Diabetic Retinopathy
Diabetes is a disease that occurs when your blood glucose (sugar) is too high. Blood glucose is your main source of energy and comes from the food you eat. Normally, a hormone called insulin—that is produced by the pancreas—keeps the level of glucose in our blood in check. However, in type 1 diabetes, the body does not make insulin, and in type 2 diabetes, the body does not respond normally to the insulin it makes.
If you have diabetes, it can attack many parts of the body, including the kidneys (diabetic nephropathy), nerve endings (diabetic neuropathy), and the back of the eye (diabetic retinopathy). Many people with diabetes also have high cholesterol and triglycerides in their blood, which increases the risk of having a heart attack or stroke.
What is Diabetic Retinopathy?
Diabetic retinopathy develops as the blood vessels of the retina become damaged over time by elevated blood sugar. While the smallest blood vessels throughout the body are affected, the retina is the earliest tissue to show injury due to its rapid metabolism. Diabetic patients must have regular eye exams to detect the earliest features of the disease before their vision begins to suffer; early recognition and proactive intervention are key to preserving eyesight.
Diabetic retinopathy progresses through a series of stages:
- In the earliest clinically recognizable stage, mild nonproliferative retinopathy, blood vessels start to develop small dilations, known as microaneurysms. These swellings may leak fluid into the retina. There are often no symptoms at this stage, which is why many people with the condition don’t seek help.
- During moderate nonproliferative retinopathy, an increasing number of microaneurysms form. When they begin to leak fluid into the macula, the center of the retina where focusing occurs, swelling occurs and it causes a condition known as diabetic macula edema (DME). People with DME may begin to notice blurring or distortion of their vision. According to the National Eye Institute, about half of all people with diabetic retinopathy will develop DME. The condition is more likely to occur as diabetic retinopathy worsens.
- Severe nonproliferative retinopathy is more widespread, affecting blood vessels throughout the retina, resulting in areas of capillary closure. The bleeding from damaged retinal blood vessels can cause floating spots or cobwebs to appear in your field of vision.
- Proliferative retinopathy occurs when the extent of normal blood vessel damage stimulates new abnormal (neovascular) blood vessels to form. These blood vessels develop in the body’s attempt to counteract the loss of oxygen and nutrients caused by the closure of normal capillaries. These blood vessels grow on the surface of the retina and attach to the collagen fibers that compose the vitreous humor, the clear gel that fills the center of eye. These new blood vessels are fragile and can leak blood just from normal eye movements resulting in blurry vision. As these blood vessels continue to grow they form fibrous scar tissue which eventually contracts, raising the retina up and away from its major blood supply, in a condition known as traction retinal detachment. Traction retinal detachment requires immediate attention in order to minimize permanent vision loss.
Diabetic Retinopathy Management
Comprehensive management and regular monitoring of your diabetes is the first—and perhaps the most important—step in the treatment process. That includes getting your hemoglobin A1c level, blood pressure, and lipid levels under the best possible control. Multiple studies have demonstrated that when these indicators are as close to normal as possible, you are less likely to develop diabetic retinopathy—and more likely to slow its progress if it does occur. Diabetes management should include:
- maintaining a healthy diet and exercising regularly
- taking prescribed medication
- controlling high blood pressure
- limiting alcohol intake and avoiding smoking
- attending regular diabetes check-ups
- having a comprehensive dilated eye exam every four to six months
In addition, with early detection of the disease, you can reduce the risk of blindness by 95 percent. For that reason, people with diabetes should have a thorough, dilated eye exam once a year, and even more frequently if diabetic retinopathy has already been diagnosed. Regular eye examinations are especially important for:
- people who have had diabetes five years or longer
- people who have difficulty controlling the level of sugar in their blood
- diabetic women who are pregnant
All of these people are at increased risk for diabetes-associated eye problems.
Diabetic Retinopathy Treatment Options
Depending on the stage of the diabetic retinopathy, your ophthalmologist has several treatment options:
- Eye Injections: Anti-VEGF (vascular endothelial growth factor), a first-line treatment in which medicine is injected directly into the eye. The purpose of anti-VEGF agents is to block abnormal blood vessel growth and, in the case of macula edema, reduce swelling. Commonly used anti-VEGF agents by ophthalmologists are ranibizumab (Lucentis®), bevacizumab (Avastin®), and afibercept (Eylea®). The treatment—performed in a doctor’s office—is made painless for the patient by administration of local anesthesia. The process requires repeated injections at intervals determined by your physician depending on the severity of your condition and your response to the medication.
- Laser Surgery: Retinal laser photocoagulation, which uses laser applications to the retina to treat damaged tissue, causes regression of leaking blood vessels that lead to diabetic macula edema and proliferative retinopathy. New York Eye and Ear Infirmary is the only ophthalmic center in the area that offers Computer-Navigated Laser Treatment, providing its surgeons with pinpoint accuracy for targeting areas of the retina that need treatment. This state-of-the-art approach is also faster and more comfortable for patients than standard laser treatment.
- Surgery: Vitrectomy, is a surgical procedure where the surgeon removes the vitreous (the clear, gel-like substance) that fills the central chamber of the eye with the help of tiny instruments that are inserted into the eye. This enables removal of blood that has leaked into the vitreous and clouded vision, or of scar tissue that is pulling on the retina, producing a detachment. Laser treatment is often performed as part of the procedure, and the cloudy vitreous is replaced with clear saline fluid. As the eye heals, it produces its own replacement fluid to take the place of the excised vitreous. NYEE’s surgeons have extensive experience performing minimally invasive, small gauge vitrectomies, which minimize complications and promote quicker recovery.
What Can I Do if I Already Lost Vision from Diabetic Retinopathy?
There are many useful devices that can help a partially-sighted person to make the most of his or her remaining vision. Called low vision aids, these devices have special lenses or electronic systems that produce enlarged images of nearby objects. If you need low vision aids, NYEE’s eye care specialists can help you identify the proper device.