CASP1 and diabetes mellitus: According to Tien et al., the apoptosis of retinal capillary cells begins early in DM and probably contributes to capillary obliteration; these authors suggest that caspases, which are proteolytic enzymes closely involved in cell apoptosis, especially caspase-1, which has been increased in DM and is distributed in a non-uniform manner so that the temporal retina has greater activation of caspase-1, play an important role in the development of DR and in the different distribution of microaneurysms.