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).   

In the early stages, you might not have any symptoms but as the condition progresses the following symptoms can occur; 

  • 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

Diabetic retinopathy usually affects both eyes.

Over time, too much sugar in the blood can lead to the blockage of the tiny blood vessels that nourish the retina, cutting off the blood supply.  As a result, the eye attempts to grow new blood vessels.  But these new blood vessels don't develop properly and can leak.    

Types of Diabetic Retinopathy

There are two types of diabetic retinopathy:

Early diabetic retinopathy - In this more common form — called Nonproliferative diabetic retinopathy (NPDR).  When you have NPDR, the walls of the blood vessels in your retina weaken. Tiny bulges (micro aneurysms) protrude from the vessel walls of the smaller vessels, sometimes leaking fluid and blood into the retina. Larger retinal vessels can begin to dilate and become irregular in diameter, as well. NPDR can progress from mild to severe, as more blood vessels become blocked.

Nerve fibers in the retina may begin to swell. Sometimes the central part of the retina (macula) begins to swell (macular edema), a condition that requires treatment.

Advanced diabetic retinopathy - Diabetic retinopathy can progress to this more severe type, known as Proliferative diabetic retinopathy. In this type, damaged blood vessels close off, causing the growth of new, abnormal blood vessels in the retina.  These new abnormal blood vessels can leak into the clear, jelly-like substance that fills the center of your eye (vitreous).

Eventually, scar tissue stimulated by the growth of new blood vessels may cause the retina to detach from the back of your eye. If the new blood vessels interfere with the normal flow of fluid out of the eye, pressure may build up in the eyeball. This can damage the nerve that carries images from your eye to your brain (optic nerve), resulting in glaucoma.

Diabetic retinopathy and macular edema are detected during a comprehensive eye exam.  Your exam should include; visual acuity testing, dilating of the pupils, tonometry reading to check the eye pressure, and Optical Coherence Tomography (OCT) images of your retina.  Your eye care professional will also check your retina for early signs of the disease. 

Treatment

During the first three stages of diabetic retinopathy, no treatment is needed, unless you have macular edema.   Macular edema is treated either with anti-vascular endothelial growth factor (anti-VEGF) therapy of laser photo-coagulation. 

Anti-Vascular Endothelial Growth Factor (Anti-VEGF) Therapy

This uses drugs that have been developed specifically for use in the eye.  VEGF is thought to trigger abnormal leaking blood vessels in the macula which leads to edema.  Anti-VEGF drugs are injected into the eye to help prevent this from happening.

Laser Photocoagulation

With laser photocoagulations, your doctor will place laser burns in areas where leaky blood vessels are affecting central vision.  This slows the leakage of fluid and reduces the amount of fluid in the retina.  

 In some cases, your eye care professional may recommend a combination of the available treatments.  These treatment are not cures and conditioning and monitoring is essential.  It is important for you to get regular eye checkups, keep your blood sugar under control and make lifestyle changes that can reduce your risk of vision loss.