Retinopathy, diabetic

Diabetic Retinopathy

Diabetic retinopathy is a diabetes complication that affects the eyes. It is caused by damage to the blood vessels of the light-sensitive tissue at the back of the eye (retina). Initially, diabetic retinopathy may cause no symptoms or only mild vision problems, but it can lead to blindness if left untreated.

Pathophysiology

Diabetic retinopathy occurs when high blood sugar levels cause damage to the blood vessels in the retina. These blood vessels can swell and leak, or they can close, stopping blood from passing through. Sometimes abnormal new blood vessels grow on the retina. All of these changes can steal your vision.

The condition can progress through four stages:

1. Mild Nonproliferative Retinopathy: At this earliest stage, microaneurysms occur. They are small areas of balloon-like swelling in the retina's tiny blood vessels. 2. Moderate Nonproliferative Retinopathy: As the disease progresses, some blood vessels that nourish the retina are blocked. 3. Severe Nonproliferative Retinopathy: Many more blood vessels are blocked, depriving several areas of the retina of their blood supply. These areas send signals to the body to grow new blood vessels for nourishment. 4. Proliferative Retinopathy: At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels. These new blood vessels are abnormal and fragile. They grow along the retina and along the 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.

Symptoms

In the early stages of diabetic retinopathy, you might not notice any symptoms. As the condition progresses, symptoms may include:

- Spots or dark strings floating in your vision (floaters) - Blurred vision - Fluctuating vision - Impaired color vision - Dark or empty areas in your vision - Vision loss

Risk Factors

Several factors can increase your risk of developing diabetic retinopathy:

- Duration of diabetes — the longer you have diabetes, the greater your risk of developing diabetic retinopathy - Poor control of your blood sugar level - High blood pressure - High cholesterol - Pregnancy - Tobacco use

Diagnosis

Diabetic retinopathy is diagnosed through a comprehensive eye exam that includes:

- Visual acuity test: This test uses an eye chart to measure how well you see at various distances. - Dilated eye exam: Drops placed in your eyes widen (dilate) your pupils to allow your doctor to see more of the inside of your eyes. Using a special magnifying lens, your eye doctor can examine your retina and optic nerve for signs of damage. - Fluorescein angiography: In this test, a dye is injected into your arm. Pictures are taken as the dye circulates through your eyes' blood vessels, allowing your doctor to identify closed, broken, or leaking blood vessels. - Optical coherence tomography (OCT): This test provides cross-sectional images of the retina, showing its thickness and helping to determine whether fluid has leaked into retinal tissue.

Treatment

Treatment, which depends largely on the type of diabetic retinopathy you have and how severe it is, is aimed at slowing or stopping the progression of the condition.

- Laser treatment (photocoagulation): This treatment can stop or slow the leakage of blood and fluid in the eye. - Vitrectomy: This procedure involves the removal of the vitreous gel and blood from leaking vessels in the back of the eye. - Injections: Medications injected into the eye can help stop the growth of new blood vessels and decrease fluid buildup.

Prevention

You can't always prevent diabetic retinopathy. However, regular eye exams, good control of your blood sugar and blood pressure, and early intervention for vision problems can help prevent severe vision loss.

Also see

- Diabetes mellitus - Macular edema - Retinal detachment - Ophthalmology