Although most research to date has related to the treatment of Keratoconus, a role for CXL has also been suggested for other forms of corneal ectasia and some unrelated corneal conditions. The Indications Include Keratoconus Pellucid marginal degeneration Iatrogenic keratectasia (post-laser in situ keratomileuses) Prevention of keratectasia (prior to refractive surgery) Bullous keratopathy Microbial keratitis Corneal (stromal) ulceration Donor tissue modification prior to keratoplasty Although cross-linking has been used in all these circumstances, other than for progressive Keratoconus, there is currently little published evidence to support these applications.