Diabetic retinopathy occurs due to the damaging effects of diabetes on the integrity of the sealed walls of the blood vessels in the retina at the back of the eye.
Vision loss results in two ways:
- Fragile, abnormal blood vessels can develop and leak blood into the central vision area, the macula. This is proliferative retinopathy and is the fourth and most advanced stage of the disease.
- Fluid can leak into the centre of the macula, making the macula swell and causing blurred vision. This is called macular oedema. Its likelihood increases with more advanced disease.
Most people with diabetes have background retinopathy. They are only minor changes that act as warning signs that diabetic control is inadequate and more serious complications are being risked if control does not improve. Usually you will not notice any vision changes other than perhaps blurred areas in your vision with fine detail tasks.