Cotton-wool spots are greyish-white patches of discoloration in the nerve fibre layer which have indistinct (fluffy) edges. They are the result of local ischaemia which leads to disruption of axoplasmic flow.
Cotton-wool spots are common and one or two do not require intervention. However, multiple cotton wool spots (more than 6 in one eye) indicate generalised retinal ischaemia and this is regarded as a pre-proliferative state.
