Diabetic retinopathy affects people with diabetes. The leading cause of blindness in American adults, it is caused by changes in the blood vessels of the retina.This diabetic eye disease weakens the small blood vessels in the retina. Retinal blood vessels can break down, leak, or become blocked - affecting and impairing vision over time. In some people with diabetic retinopathy, damage to the eye can occur when abnormal new blood vessels grow on the surface of the retina.

In the late stages of diabetic retinopathy, you may have blind spots and/or floaters.

Symptoms

Often, there are no symptoms in the early stages of diabetic retinopathy. Vision may seem unchanged until the disease becomes severe. Eventually, the vision of a person with diabetic retinopathy may become blurred or blocked entirely. But even in more advanced cases the disease may progress without symptoms for a long time. That is why regular eye exams are so important for people with diabetes.

Fluorescein Angiography

The blood vessels in the eyes cannot be distinguished from the surrounding structure of the eye in conventional imaging techniques. Doctors can however document potential damage caused by diabetic retinopathy by injecting a substance that "lights up" the veins. This simple procedure provides a clear picture of the retinal blood vessels for diagnosis.

Stages

The early stage of this disease is called nonproliferative diabetic retinopathy. In this stage blood vessels swell and sometimes bulge or balloon (aneurysm). The vessels may leak fluid that can build up in the retina and cause swelling. This condition is called macular edema, and it changes the vision of individuals with the disease. The blurriness is sometimes compared to trying to look through water.

The fluid deposits that build up in the retina may clear up on their own, but fatty deposits sometimes remain that can affect vision. Later, vessels may begin to bleed inside the retina.

In many cases when the small blood vessels close down, new, unhealthy blood vessels grow. These unhealthy blood vessels are not able to feed the retina. This stage of the disease is known as proliferative diabetic retinopathy.

The unwanted blood vessels can grow on the back of the vitreous. Vitreous is the clear jelly-like fluid that fills most of the eyeball. vessels may also bleed into the vitreous. This bleeding may cause dark spots (floaters), strands that look like cobwebs, or clouded vision.

As vessels heal, scar tissue may also grow. The scar tissue sometimes pulls the retina away from the back of the eye. As a result, the retina can tear or come completely loose from the eye. A detached or torn retina may result in serious loss of sight or even blindness.

In nonproliferative retinopathy, a slight deterioration in the small blood vessels of the retina, portions of the vessels may swell and leak fluid into the surrounding retinal tissue.	Proliferative retinopathy, an advanced form of diabetic retinopathy, occurs when abnormal new blood vessels and scar tissue form on the surface of the retina.	Diabetic macular edema (abnormal accumulation of fluid, fat and proteins in the macular part of the retina).

Terms:

Macular edema - occurs when fluid building up in the retina causes swelling and affects vision.

Nonproliferative - diabetic retinopathy occurring without the growth of unhealthy blood vessels (neovascularization or new vessels)

Proliferative - diabeticic retinopathy occurring when the breakdown of retinal blood vessels leads to the growth of new, unhealthy blood vessels (neovascularization).

Treatment

Doctors have a range of options for treating individuals who have been diagnosed with diabetic retinopathy.

Photocoagulation (Laser surgery)
A common treatment for some forms of retinopathy is photocoagulation. In this procedure, the doctor uses a laser to seal leaking or bleeding vessels. During the treatment, the laser beam is carefully aimed at problem areas.

In advanced cases of diabetic retinopathy, more laser treatment may be needed. "Pan-retinal photocoagulation" uses a laser beam to treat many places on the retina. This technique helps prevent the growth of new, unhealthy blood vessels. Note: laser treatments are not used for every case of diabetic retinopathy.

Vitrectomy
Another treatment for some advanced cases of diabetic retinopathy is vitrectomy. It is used when there is unhealthy vessel growth and bleeding. During this operation, the doctor uses a small suction tool to take out the vitreous jelly containing blood and scar tissue strands inside the eye. At the same time, the doctor uses fluid to replace the vitreous in the patient's eye.

Hope for the future

Scientists are still working toward a better understanding of diabetic retinopathy, and new treatment options are on the horizon. In the meantime, early detection of retinopathy and close watch by an eye doctor are major goals for the successful treatment of patients with diabetes.

People with diabetes need to know that dangerous changes in the retina often happen before they notice changes in their sight. All people with diabetes should have a professional eye exam at least once a year. The eye doctor can decide if you need more frequent exams. People with diabetes should also get regular medical care to control their diabetes.