People with diabetes can have an eye disease called diabetic retinopathy. This is when high blood sugar levels cause damage to 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.
Stages of diabetic eye disease
There are two main stages of diabetic eye disease.
- NPDR (non-proliferative diabetic retinopathy)
- This is the early stage of diabetic eye disease. Many people with diabetes have it.
- With NPDR, tiny blood vessels leak, making the retina swell. When the macula swells, it is called macular edema. This is the most common reason why people with diabetes lose their vision.
- Also with NPDR, blood vessels in the retina can close off. This is called macular ischemia. When that happens, blood cannot reach the macula. Sometimes tiny particles called exudates can form in the retina. These can affect your vision too.
- If you have NPDR, your vision will be blurry.
- PDR (proliferative diabetic retinopathy)
- PDR is the more advanced stage of diabetic eye disease. It happens when the retina starts growing new blood vessels. This is called neovascularization. These fragile new vessels often bleed into the vitreous. If they only bleed a little, you might see a few dark floaters. If they bleed a lot, it might block all vision.
- These new blood vessels can form scar tissue. Scar tissue can cause problems with the macula or lead to a detached retina.
- PDR is very serious, and can steal both your central and peripheral (side) vision.
What Causes Diabetic Retinopathy?
When blood sugar levels are too high for extended periods of time, it can damage capillaries (tiny blood vessels) that supply blood to the retina. Over time, these blood vessels begin to leak fluids and fats, causing edema (swelling). Eventually, these vessels can close off, called ischemia. These problems are signs of non-proliferative diabetic retinopathy (NPDR).
As diabetic eye problems are left untreated, proliferative diabetic retinopathy (PDR) can develop. Blocked blood vessels from ischemia can lead to the growth of new abnormal blood vessels on the retina (called neovascularization) which can damage the retina by causing wrinkling or retinal detachment. Neovascularization can even lead to glaucoma, damage to the optic nerve that carries images from your eye to your brain.
Maintaining strict control of blood sugar and blood pressure, as well as having regular diabetic retinopathy screenings by your Eye M.D., are keys to preventing diabetic retinopathy and vision loss. Controlling blood sugar and also help to prevent the development of cataracts, as diabetes is a risk factor for cataracts.
Diabetic Retinopathy Symptoms
You can have diabetic retinopathy and not know it. This is because it often has no symptoms in its early stages. As diabetic retinopathy gets worse, you will notice symptoms such as:
- seeing an increasing number of floaters
- having blurry vision
- having vision that changes sometimes from blurry to clear
- seeing blank or dark areas in your field of vision
- having poor night vision
- noticing colors appear faded or washed out
- losing vision
Diabetic retinopathy symptoms usually affect both eyes.