ICAM1 and diabetes mellitus: Indeed, ICAM-1 is found to be highly expressed in the blood vessels of the retina, choroid and fibrovascular membrane in patients with diabetes [5, 44], and its expression correlates with the number of migrated neutrophils in the retina and choroid of these patients [5], indicating that elevated ICAM-1 facilitates leukocyte recruitment and the vascular complications in DR.