I have an article published in this month's Journal of Refractive Surgery titled: Traumatic Dislocation of LASIK Flaps 4 and 9 Years After Surgery. With the help of UMDNJ ophthalmology resident, H. Jane Kim, we published two cases of traumatic flap dislocation following LASIK. One of the cases occurred 9 years following LASIK, making it the longest reported case medical literature. In this case the flap dislocated when my patient was struck in his eye with a dog's paw. After treatment both of my patients vision improved to 20/20.
This article brings up an important point, there is a potential to dislocate the LASIK flap if one is hit at the right angle, years after LASIK surgery. This is one of the reasons I advocate treating those patients who are involved in activities (boxers, special forces, etc) that may preclude them to get hit in the eye with surface treatments such as LASEK. This procedure creates no flap, and thus minimizes future risk.