Figure 4. Transmission electron micrographs (TEM) of stromal lenticule showing keratocytes. A, C: Fresh lenticule. B, D: Cryopreserved lenticule. A, B: Apoptotic keratocytes with cromatin condensation and fragmentation, apoptotic bodies, loss of cytoplasm and cell shrinkage. C, D: Necrotic keratocyte, with incomplete nuclear membrane and vacuoles in the cytoplasm. Magnification, 8900×.