Diabetes is a disease that occurs when your blood glucose (sugar) is too high. Blood glucose is your main source of energy and comes from the food you eat. Normally, a hormone called insulin—that is produced by the pancreas—keeps the level of glucose in our blood in check. However, in type 1 diabetes, the body does not make insulin, and in type 2 diabetes, the body does not respond normally to the insulin it makes.
If you have diabetes, it can attack many parts of the body, including the kidneys (diabetic nephropathy), nerve endings (diabetic neuropathy), and the back of the eye (diabetic retinopathy). Many people with diabetes also have high cholesterol and triglycerides in their blood, which increases the risk of having a heart attack or stroke.
What is diabetic retinopathy?
Diabetic retinopathy develops as the blood vessels of the retina become damaged over time by elevated blood sugar. While the smallest blood vessels throughout the body are affected, the retina is the earliest tissue to show injury due to its rapid metabolism. Diabetic patients must have regular eye exams to detect the earliest features of the disease before their vision begins to suffer; early recognition and proactive intervention are key to preserving eyesight.
Diabetic retinopathy progresses through a series of stages:
- In the earliest clinically recognizable stage – mild nonproliferative retinopathy – blood vessels start to develop small dilations, known as microaneurysms. These swellings may leak fluid into the retina. There are often no symptoms at this stage, which is why many people with the condition don’t seek help.
- During moderate nonproliferative retinopathy, an increasing number of microaneurysms form. When they begin to leak fluid into the macula, the center of the retina where focusing occurs, swelling occurs and it causes a condition known as diabetic macula edema (DME). People withDME may begin to notice blurring or distortion of their vision. According to the National Eye Institute, about half of all people with diabetic retinopathy will develop DME. The condition is more likely to occur as diabetic retinopathy worsens.
- Severe nonproliferative retinopathy is more widespread, affecting blood vessels throughout the retina, resulting in areas of capillary closure. The bleeding from damaged retinal blood vessels can cause floating spots or cobwebs to appear in your field of vision.
- Proliferative retinopathy occurs when the extent of normal blood vessel damage stimulates new abnormal (neovascular) blood vessels to form. These blood vessels develop in the body’s attempt to counteract the loss of oxygen and nutrients caused by the closure of normal capillaries. These blood vessels grow on the surface of the retina and attach to the collagen fiber that compose the vitreous humor, the clear gel that fills the center of eye. These new blood vessels are fragile and can leak blood just from normal eye movements resulting in blurry vision. As these blood vessel continue to grow they form fibrous scar tissue which eventually contracts, raising the retina up and away from its major blood supply, in a condition known as traction retinal detachment. Traction retinal detachment requires immediate attention in order to minimize permanent vision loss.