Types of Diabetic Retinopathy

Background retinopathy is an early stage of diabetic retinopathy.

In this stage, tiny blood vessels within the retina become damaged and leak blood or fluid. Leaking fluid causes the retina to swell or to form deposits called exudates.

While this stage usually doesn't affect your vision, it can lead to more sight threatening stages. For this reason, background retinopathy is considered a warning sign.

Sometimes the leaking fluid collects in the macula, the part of the retina that lets us see fine details, like letters or numbers. This problem is called macular edema. Reading and close work may become more difficult because of this condition. Macular edema usually requires prompt laser treatment.

Proliferative retinopathy describes the changes that occur when new, abnormal blood vessels begin growing on the surface of the retina.

The abnormal growth is called neovascularization. These new blood vessels have weaker walls and may break and bleed. The vitreous is the clear, jelly-like substance that fills the centre of the eye. Leaking blood can cloud the vitreous and partially or completely block the light passing through the pupil towards the retina, causing blurred and distorted images or in the worst cases complete blindness.

These abnormal blood vessels may grow scar tissue that can pull the retina away from the back of the eye. This is called a retinal detachment. If left untreated, a retinal detachment can cause severe vision loss.

Abnormal blood vessels may also grow around the pupil (on the iris) causing glaucoma by increasing pressure within the eye.

Proliferative diabetic retinopathy is the most serious form of diabetic retinal disease. It affects up to 20% of diabetics and can cause severe loss of sight, including blindness.