In patients with diabetes, the hyperglycaemia is known to promote high levels of
diacylglycerol which activates protein kinase C (PKC) in the vascular tissues and leads to
production of vascular endothelial growth factor (VEGF) in the retina. PKC activation is likely
to play a key role in diabetic microvascular complications, particularly changes in vascular
permeability and ischaemia in the retina. A new potential therapeutic agent, the PKC-β
inhibitor ruboxistaurin, has been studied in animal and human clinical trials in diabetic …