According to this article: http://www.npr.org/templates/story/story.php?storyId=6305599

there is a 1 in 100K chance of serious complications for modern LASIX requiring corneal transplant. That's a higher incidence than the chance of getting AK if you wear contact lenses.

Both are terrible complications but I don't see the rationale of avoiding AK by getting LASIX. I couldn't find any literature but it seems to me that the fact that LASIX damages the cornea for a time would also leave one open to an infection in addition to the complications.