Microvascular lesions of diabetic retinopathy: clues towards understanding pathogenesis?
Retinopathy is a major complication of diabetes mellitus and this condition remains a leading cause of blindness in the working population of developed countries. As diabetic retinopathy progresses a range of neuroglial and microvascular abnormalities develop although it remains unclear how these pathologies relate to each other and their net contribution to retinal damage. From a haemodynamic perspective, evidence suggests that there is an early reduction in retinal perfusion before the onset of diabetic retinopathy followed by a gradual increase in blood flow as the complication progresses. The functional reduction in retinal blood flow observed during early diabetic retinopathy may be additive or synergistic to pro-inflammatory changes, leucostasis and vaso-occlusion and thus be intimately linked to the progressive ischaemic hypoxia and increased blood flow associated with later stages of the disease. In the current review a unifying framework is presented that explains how arteriolar dysfunction and haemodynamic changes may contribute to late stage microvascular pathology and vision loss in human diabetic retinopathy.
Curtis
T M
TM
Centre for Vision and Vascular Science, The Royal Victoria Hospital, Institute of Clinical Sciences, The Queen's University of Belfast, Belfast, UK. t.curtis@qub.ac.uk
Gardiner
T A
TA
Stitt
A W
AW
D003920:Diabetes Mellitus / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D000860:Hypoxia / Q000209:etiology; D008833:Microcirculation / Q000502:physiology; D012039:Regional Blood Flow; D012171:Retinal Vessels / Q000502:physiology*