“…CXL has in recent years showed promising results when used to treat severe forms of infectious keratitis17, 18, 19, 20, 21, 22, 23, 24, where in such cases the treatment is termed PACK-CXL. The microbicidal effect of PACK-CXL is thought to be mediated through the combined effects of UVA-induced DNA damage and release of reactive oxygen species (ROS) by riboflavin 25 , 26 , while the following post-procedure relief in pain is thought to be mediated by the combined effects of suppression of inflammation 27 and a transient reduction of nociceptive subepithelial nerves 28 …”