Busin M, Bovone C, Scorcia V, et al. - Researchers conducted this multicenter study to investigate the ultrastructure of the natural plane of separation in grafted corneas and assess the outcomes of stromal peeling. Stromal peeling was tried in 96 consecutive eyes with unsatisfactory vision following penetrating keratoplasty (PK) for keratoconus (n = 79), herpetic keratitis (n = 11) and granular dystrophy (n = 6). In all cases, the natural plane of separation was identified. The presence of a natural plane of separation identified intraoperatively is supported by ultrastructural changes in the stromal microarchitecture of grafted corneas. Stromal peeling can be performed successfully in post-PK eyes with a variety of stromal pathology.