Diabetic Retinopathy

Diabetic retinopathy (DR) is a complication of diabetes mellitus and is one of the main causes of blindness in working-age adults around the world. It occurs when diabetes damages the tiny blood vessels inside the retina, which is the light-sensitive tissue at the back of the eye. A healthy retina is essential for good vision.

Diabetic retinopathy often has no early warning signs. But over time, it can get worse and in the moderate to late stages, it can cause vision loss. Diabetic retinopathy usually affects both eyes, though one eye may be more severely affected.

What are the types of diabetic retinopathy?

There are 2 main types of diabetic retinopathy: 

• Non-proliferative diabetic retinopathy, also known as background diabetic retinopathy is the early stage of diabetic retinopathy and occurs when the small retina blood vessels become affected and begin to leak and bleed. At this stage, vision is usually not affected.
  
  
• Proliferative diabetic retinopathy (PDR) is associated with a high risk of permanent loss of vision. There is growth of abnormal new blood vessels in the retina. These abnormal new vessels can rupture, causing significant bleeding that will lead to loss of vision. The abnormal blood vessels can also cause scar formation and retinal detachment. In some cases, abnormal blood vessels can block fluid outflow from the eye and cause a severe type of glaucoma called neovascular glaucoma, which carries a high risk of optic nerve damage and blindness.
  
  

Besides bleeding and retinal detachment, another way that DR can affect vision is by causing leakage from blood vessels and swelling of the retina, called diabetic macular edema (DME).  This tends to occur in the central part of the retina called the macula, which is important for sharp central vision. Swelling of the macula causes degeneration of the retinal cells over time, and affects central vision. DME is now the most common cause of vision loss from DR.

Proliferative diabetic retinopathy with abnormal new blood vessels, bleeding and leakage in the retina 

Proliferative diabetic retinopathy causing retinal detachment