“…1 Firstly, donor epithelial defects can be intimately related to limbal stem cell function as early as the first day postoperativelyFAhmed and Ahmed have shown that corneal epithelial cell migration rate is 61 mm/h during the active healing phase of the epithelium, which means that the defect may close in 18-48 h, or even faster. 2 This rapid rate of recovery is a response to wounding, which has been conclusively shown by Lehrer et al 3 using double-labelling techniques. The latter experiments demonstrate three mechanisms to account for the persistent epithelial defect on day 1 following corneal grafting.…”