Diabetic eye disease

Diabetic eye disease primarily affects the retinal vasculature, but the iris and lens can also be involved. Proliferative retinopathy is the commonest sight threatening lesion in type 1 diabetes, whilst for type 2 diabetes it is macular oedema. Diabetic retinopathy can be classified as non- proliferative and proliferative. New vessel growth or neovascularisation is the hallmark of proliferative retinopathy and results from the local release of growth factors in response to ischaemia. The most common cause of visual loss, however, is maculopathy which results from ischaemia and subsequent oedema of the central retina. Anterior ischaemic optic neuropathy is caused by microvascular disease of the anterior optic nerve. Patients present with painless loss of vision usually upon wakening. Both the DCCT in type 1 and the UKPDS in type 2 diabetes demonstrated the benefit of glycaemic control for the primary prevention of new retinopathy, and secondary prevention of progression of existing retinopathy.