Cell death in rat retina after pressure-induced ischaemia-reperfusion insult: electron microscopic study. II. Outer nuclear layer.

Pressure-induced ischaemia-reperfusion insult of sufficient duration leads to significant retinal damage in rats. In this report we describe the morphology of degenerating cells in the outer nuclear layer at several time points after the insult, as observed by electron microscopy. Only one death pattern was observed. It was characterized by asynchronous involvement of individual cells, progressive densification and shrinkage of nuclear and cytoplasmic components, and a final phase of disaggregation and heterophagic elimination by Müller cells. This pattern of cell death combined features of an apoptosis-like mechanism and secondary necrosis.