What is Diabetic Retinopathy?
People with diabetes can develop a diabetic eye disease called diabetic retinopathy. Diabetic retinopathy is the most common cause of vision loss in people with diabetes and is the number one cause of adult blindness. It is caused when high blood sugar levels damage small blood vessels in the retina (the equivalent to a camera film that lines the back of the eye).
In diabetic retinopathy, both eyes are usually affected, though not always by the same amount. Several things can happen because of this damage:
- The blood vessels can swell and leak causing swelling of the retina, also known as macular edema, which leads to vision blurry.
- The damaged blood vessels can become blocked, preventing blood from passing through. This leads to loss of oxygen and nutrients delivered to the retina.
- When the disease progresses, abnormal blood vessels and scar tissue grow on the retina that can bleed or cause a retinal detachment.
- If diabetic eye disease isn’t monitored or treated when needed, you can permanently lose vision.
What are symptoms of diabetic retinopathy?
Diabetic retinopathy may not have symptoms until late in the disease. They include:
- Loss of central vision, which is needed for reading and driving
- Trouble seeing colors
- Blurry vision
- Black spots in your vision
- Floaters, or “cobwebs”in your vision from bleeding inside the eye
What are the stages of diabetic eye disease?
There are two main stages of diabetic eye disease.
Non-proliferative diabetic retinopathy (abbreviated NPDR). This is the early stage of diabetic eye disease that develops in almost all diabetic patients over time.
- In this stage, small blood vessels can leak and cause the retina to swell (known as macular edema when the macula swells). This is the most common cause for loss of vision or blurry vision.
- Also with NPDR, blood vessels in the retina can close off. This prevents blood from reaching the retina, also known as ischemia.
- Sometimes tiny cholesterol or fats collect in the retina, known as exudates, that can impair vision too.
Proliferative diabetic retinopathy (abbreviated as PDR)
- PDR is the more advanced stage of diabetic eye disease. It happens when there are new blood vessels growing, a process called neovascularization. These new vessels are very weak and often bleed inside of the eye causing dark floaters. If they bleed a lot, all of your vision may be blocked.
- These new blood vessels are often associated with scar tissue. Scar tissue can cause problems such as a tractional retinal detachment.
- PDR is very serious, and can affect both your central and peripheral (side) vision. Surgery may be ultimately required to help restore vision.
How is diabetic eye disease diagnosed and treated?
Dr. Tieu will be able to diagnose diabetic eye disease by dilating your eyes and doing special tests including digital histology and angiograms looking at the blood flow in the retina. Treatment for diabetic retinopathy often includes injections in your eye, lasers and surgery. It depends on the stage of disease and why you are losing vision. Dr. Tieu will explain how the treatments work for your eyes.