Diabetic retinopathy is classified on the basis of the alterations in eye, whereas their amount and severity can be different in both eyes:
- Background retinopathy – this is the earliest stage of the disease and occurs rarely before 8-10 years of diabetes history. Visual acuity is normal and there is no risk for its decrease. However, the emergence of many small haematomas, fragile blood vessels and exudates – this refers to the development of retinopathy, which warrants more frequent checks (every 6-12 months).
- Pre-proliferative retinopathy – thus developmental stage of retinopathy is characterised by widening, distortion and leakage of the veins of the retina. There are more haematomas in the eye and they may me larger. A number of different exudates are also present.
- Proliferative and advanced retinopathy – when blood vessels get obstructed retina is deprived of oxygen and nutrients. New, abnormal blood vessels start to grow into the eye in order to restore the blood supply and nutrition of the retina. These new blood vessels are fragile and can cause haematomas in the vitreous body. Small haematomas cause blurring of the vision (stripes or floaters occur before the vision), but large haemorrhage causes significant impairment of vision. New blood vessels also promote the proliferation of connective tissue that can cause detachment of the retina and loss of sight.