Clinical Phenotypes and Cellular Mediators in Diabetic Retinopathy

The aim of this work was to establish meaningful clinical end-points and surrogate markers for diabetic macular ischaemia, a condition for which there is no treatment. The relationship between diabetic eye disease and circulating cellular mediators of angiogenesis and inflammation was further explored with a view to developing therapy in the longer term. Visual loss in diabetic macular ischaemia was observed to occur only in moderate to severe disease, progresses at a rate of 5-10% increase in area per year and associated with thinning of the retinal nerve fibre layer. Direct visualisation of cells in the vitreous was achieved using optical coherence tomography. Novel methods for this were further developed in inflammatory eye disease, with a view for application in diabetic eye disease. A method for in vivo labelling of cells using ICG to enhance visualisation was described. In the field of regenerative medicine, this technique may allow direct visualisation of cell-mediated inflammation regardless of the type of cell or tissue transplanted. EPC and monocyte profiles were analysed in the context of diabetic eye disease. Elevated levels of EPCs as defined by CD34+ CD309+ were observed in diabetes, but no associations were observed with progression. There were no initial associations between monocyte subsets and diabetic eye disease severity at the outset but differences were observed in the context of progression. Observations from this work support the notion that inflammation plays an important role in diabetic eye disease and will inform development of new treatments in this field