How does diabetic retinopathy cause vision loss?

There are 3 types of diabetic retinopathy:

Non-proliferative diabetic retinopathyProliferative diabetic retinopathyDiabetic macular edema
Non-proliferative diabetic retinopathy is the earliest stage of diabetic retinopathy. In this stage, the damaged tiny blood vessels in the retina may begin to leak fluid and small amounts of blood hence causing the retina to swell or forming yellowish deposits at the back of your eye.
This is the most severe type of diabetic retinopathy. It occurs when new blood vessels begin to grow in the inner part of the retina. As these vessels are mostly abnormal and fragile, they may eventually lead to bleeding in the eye and in severe cases, form scar tissue that may cause the retina to wrinkle or detach.
This condition occurs when the damaged blood vessels allow fluid to leak into the most visually important part of the retina called the macula that is responsible for sharp central vision. Dr Cheryl Lee’s analogy is that if the retina is Singapore, the macula is Orchard road.

 

  

Non-proliferative diabetic retinopathy.

Diabetic macular edema on high-definition optical coherence tomogram