Retina damage. Ophthalmoscope image of retinopathy caused by chronic myeloid leukaemia. The red patches are areas of bleeding (haemorrhaging) into the retina, the light-sensitive membrane at the back of the eyeball. Haemorrhages are a common feature of leukaemia. Leukaemia is a cancer of the blood-forming tissues that causes overproduction of abnormal white blood cells. This leads to a reduced amount of red blood cells and platelets being produced. Platelets are involved in the blood clotting process, so a reduction in their numbers makes haemorrhaging more likely. A lack of oxygen-carrying red blood cells causes anaemia.