Diabetic retinopathyA clinical update.

Easy observation of the fundus oculi makes retinopathy the most frequently reported chronic complication of diabetes and, consequently, the one we know best in terms of epidemiology and natural history. Achieving near-normal levels of blood glucose and blood pressure provides empirical though powerful tools for clinicians to delay the onset and progression of diabetic retinopathy. Even when these measures have failed and retinopathy becomes sight-threatening, laser photocoagulation has proven remarkably effective. Nonetheless, retinopathy remains a leading cause of blindness and there is little evidence that diabetes-related visual loss is decreasing in industrialized countries. This may result from the mixed blessing of prolonged survival of patients who had become diabetic when metabolic control was pursued less fastidiously than today. Screening for sight-threatening retinopathy is the most cost-effective medical procedure known and should help optimise the use of diagnostic and therapeutic resources, but its widest deployment still meets with inertia and lack of interest within most health care systems. Improving clinical skills and technology, however, allow us to take a more optimistic look at the future, as pathogenesis-targeted forms of treatment are being developed and tested through appropriately powered clinical trials.