Intacs have been specifically approved by the FDA for use in keratoconus patients. Corneal Crosslinking with Riboflavin (CxL)
has not. CxL is going through FDA clinical trials at this time. There is one surgeon in Beverly Hills who is doing CxL (he calls it C3R), however I have no information about how he is doing this without FDA approval.
CxL was developed in Germany and Switzerland, where there are about ten years of clinical data. The long-term stability seems appropriate. It is the short-term that is less predictable. For some people the treatment makes little or no difference and it is impossible at this time to predict who will have good results and who will have no results. There does not seem, with current knowledge, any negative effect short-term or long-term.