In addition to chronically high blood sugar, significant fluctuations in the blood sugar can also predispose person to retinal changes. High blood pressure, lipid disorders, kidney disease, anaemia, abdominal obesity and smoking can also increase the risk of diabetic retinopathy. Other predisposing factors include a long time living with diabetes, puberty, pregnancy and hereditary factors.
Over the years, too high blood sugar level damages the blood vessels of the retina. It can lead to seeping from the blood vessels or bleeding and swelling of the retina. High blood sugar can also lead to a lack of oxygen resulting from the blockage of the retinal blood vessels and, as a consequence, the development of brittle new blood vessels in the back surface of the eye, which can easily bleed into the vitreous body.