A Systematic Study of Retinal Structure and Function in Diabetic Macular Oedema

Diabetic retinopathy(DR) is a sight threatening condition that occurs in persons with diabetes. DR arises as a consequence of damage to the retinal blood vessels and is related to the high and fluctuating sugar levels in the blood stream. An eye with DR will have abnormal appearing retinal blood vessels which become engorged and dilated, leaky and fragile or undergo closure. The net result is a picture of haemorrhage and or ischaemia (lack of blood supply). A particular feature of DR is the accumulation of fluid in the macula which is the central part of the retina and responsible for detailed eye sight. This peculiar form of DR is called Diabetic Macular Oedema (DMO). DMO can occur in isolation without other features of DR. DMO is commoner in type 2 diabetes where insulin resistance and abnormalities of blood fats are found. The investigators wish to study DR and DMO using high resolution retinal imaging and functional tests in normal participants, those participants with diabetes without any overt signs of disease and those with DR and DMO in order to understand how the condition develops and whether there are any unique risk factors that can be identified