Further support for the thesis of inflammation as one of the causes of onset of diabetic retinopathy is provided by experimental studies in animals which demonstrate how hyperglycemias not only causes an increase in the production of cycloxygenase-2 (COX2), through the activation of protein-kinase (PKC) [27,28], but also in prostaglandin synthetase (PGIS) [29] a specific enzyme in the synthesis of prostaglandin PGI2 [30]. Here, PTGIS is linked to Hyperglycemia.