A serious complication of this surgery is the possibility of transmitting a lethal disease such as CJD or rabies.In the Czech Republic, legally mandatory testing for the presence of pathogenic prions in the donors'brains was introduced from Jannuary 2007.The absence of pathogenic prions from all of the 1142 tested specimens corresponds to the presumed very low risk of transmission of Creutzfeldt-Jakob disease through corneal graft transplantation.