Various organisms have been implicated with most commonly found to be of staphylococcal variant. The corneal epithelium is removed during the CXL treatment (epithelium-off method) to permit the diffusion of the riboflavin into the corneal stroma [17]. This step however reduces the immune-protective function of the superficial corneal layer against infectious agents [18].
Many surgeons are now forgoing the use of lenses postoperatively and increasing the frequency of antimicrobial drops to further reduce the risk of microbial infection after CXL [19]. Moreover linear abrasions can reduce the healing time and a CXL without removing the epithelium can be used [17, 18].
Acanthamoeba keratitis
Acanthamoeba keratitis is facilitated by the removal of the epithelium particularly if a CLenses is left in place.
It is well recognized that UV light can cause reactivation of herpes. This commonly occurs with those travelling to sunny climates or skiing in the winter.
Prophylactic systemic antiviral treatment in patients with history of herpetic disease.
It happens in the case of a stromal thickness less than 400 μm or incorrect focusing.
The threshold level of irradiance which could cause damage to the endothelium was found to be 0.35 mW/cm2, but this level is easily avoided if the corneal depth of 400 m is used as a cutoff level, with irradiance falling to 0.18 mW/cm2 when using the standard protocol. To date longer-term studies of corneal cross-linking have not shown any increased loss of endothelial cells after cross-linking compared to either the normal eyes or post-LASIK eyes [27, 28].
Treatment failure
7.6% of keratoconic progression following treatment at one-year followup [19].
