Diabetic retinopathy is the most common diabetic eye problem, causing blindness in many American adults. This disease affects the retina’s blood vessels.
Patients with diabetic retinopathy may experience swelling and leaking of the blood vessels in the retina. In other cases, new blood vessels grow on the surface of the retina. The retina is the light-sensitive tissue found at the back of the eye. It needs to be healthy to achieve good vision.
Once you have diabetic retinopathy, you may notice some vision changes. Over time, this can worsen and lead to vision loss. This condition usually damages both eyes.
There are four stages to diabetic retinopathy, which include:
Mild nonproliferative retinopathy. This is the earliest stage, where microaneurysms are common. Microaneurysms are swelling in the tiny blood vessels of the retina, similar to how a balloon swells.
Moderate nonproliferative retinopathy. When the disease develops, some of the retina’s blood vessels, which bring nourishment to the tissue, are blocked.
Severe nonproliferative retinopathy. At this stage, more blood vessels of the retina are blocked, depriving the retina of the blood supply it needs. Deprived areas of the retina then send signals to the system to grow new blood vessels to provide nourishment to the affected tissues.
Proliferative retinopathy. During this advanced stage, new blood vessels have grown, but they are abnormal and weak. They tend to grow on the surface of the retina and on the surface of the vitreous gel that provides moisture to the eyes. These growths do not cause harm by themselves, but they are weak and leak blood and other fluid into the center of the eye. This fluid affects vision and can lead to the development of scar tissue. This can cause retinal detachment and vision loss.
The blood vessels that are affected by diabetic retinopathy can cause loss of vision in two ways.
The weak, abnormal blood vessels can leak blood into the eye’s center, which causes vision blurring. This happens during proliferative retinopathy.
Fluid that leaks during this time may reach the macula, the part of the eye responsible for sharp, up close vision. When this happens, the macula swells and vision blurs. This occurrence is known as macular edema. While this may happen at any stage in diabetic retinopathy, it usually happens during the progression of the disease. Half of patients with proliferative retinopathy suffer from macular edema.
Who is at risk of diabetic retinopathy?
Patients with diabetes, both types 1 and 2, are at risk of developing diabetic retinopathy. This is the reason why every diabetic patient is advised to have a comprehensive dilated eye examination at least every year. The longer the patient has had diabetes, the greater his or her chances of developing diabetic retinopathy. In America, 40 to 45 percent of diabetics are diagnosed with some stage of diabetic retinopathy.
Pregnant women with diabetes may also have diabetic retinopathy and also need a comprehensive dilated eye exam immediately. There may be some additional exams needed for pregnant women.
How can I protect my vision?
If you are diagnosed with diabetes, it is critically important to have a comprehensive dilated eye exam at least once every year. Also take note of the following:
Proliferative retinopathy may not manifest symptoms as it progresses.
Similarly, there may not be any symptoms of macular edema at any of the stages of diabetic retinopathy.
Some patients with macular edema and proliferative retinopathy may have fine vision, but they are still at high risk for vision loss.
Your eye doctor can identify if you are suffering from macular edema or if you are under any stage of retinopathy. Whether you experience symptoms or not, early detection and early treatment are key to preventing vision loss.
Patients with diabetic retinopathy will need to undergo eye exams more often than individuals who do not have the disease. These patients may be able to reduce their risk for vision loss up to 95 percent if early treatment and follow-up care are practiced.
According to the Diabetes Control and Complications Trial, controlling blood sugar levels can delay the onset and progression of diabetic retinopathy. Diabetic people who have controlled their blood sugar levels, keeping them as close to normal levels as possible, are less likely to have nerve or kidney disease. This preventive measure can also reduce the need for laser surgery to salvage deteriorating eyesight.
The methods for controlling blood sugar are not the same for all patients, which seems obvious when considering patients may range from children under age 13 to the elderly to people with heart disease. It is advised to seek professional help to devise the best control program for you.
Other studies show a link between controlling blood pressure and cholesterol levels and a reduction of risk for vision loss. Of course, this isn’t beneficial just for your vision, but your overall health as well.
Laser surgery, more commonly known as “scatter” laser treatment, is the treatment of choice for proliferative retinopathy. In the procedure, 1,000 to 2,000 laser burns are made in certain parts of the retina, away from the macula. These burns coagulate and shrink abnormal retinal blood vessels. The procedure can require two or more sessions to make the number of necessary laser burns. You may notice some side vision loss as a side effect of the procedure, but scatter laser treatment can salvage the rest of your sight. The treatment can also slightly affect your night and color vision.
The scatter laser treatment is more effective when new blood vessels in the retina have not yet started to bleed. This is why a diabetic person should have regular comprehensive dilated eye examinations. Once the bleeding has occurred, a scatter laser treatment may still be effective if the amount of bleeding permits it. For severe bleeding, your doctor may recommend a surgical procedure known as vitrectomy, where blood is removed from the eye’s center.
Meanwhile, macular edema can be addressed with laser surgery known as “focal” laser treatment. During this procedure, small laser burns are made on retinal areas where leakage is present around the macula. The burns delay the fluid leakage in the retina. This procedure usually only requires a single session, yet follow-up treatment may be required.
Focal laser surgery may be needed more than once to control the fluid leakage. If there is macular edema in both eyes that require laser treatment, separate treatments are needed and are scheduled several weeks apart.
Focal laser surgery is done to stabilize vision. It reduces one’s risk for vision loss up to 50 percent. In cases where vision is lost, the condition can still be improved, but the damage cannot be reversed. Once there is vision loss, you need to contact your eye care professional to make plans to limit the damage.
If some sight is lost from diabetic retinopathy, your eye doctor can recommend low vision devices and services that can help you make the most of the vision that remains. Your doctor may know a specialist in low vision who can help you cope. There are various community agencies that provide counseling about low vision as well as training and other special programs for patients with visual problems. Visit your nearby school of optometry or medicine; they may have low vision services that you can try.
This is an online resource guide about diabetic eye disease. It provides detailed information on the symptoms and causes, as well further explanation on the diagnosis and the type of treatments available. References are from Don’t Lose Sight of Diabetic Eye Disease (NIH Publication No. 04-3252) and Diabetic Retinopathy: What You Should Know (NIH Publication No. 03-2171).
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