http://www.ophmanagement.com/article.aspx?article=86298

Excerpt:

Though the exact cause of TLS is still uncertain, some surgeons believe that the inflammation is caused by necrotic cellular debris, a byproduct of the gas bubbles that are formed to create the flap. Others speculate that the cause may be inflammatory cykotines migrating from the flap interface and sidewall to the perilimbal sclera and iris base.

Flap dimensions created with the IntraLase FS laser

J Cataract Refract Surg. 2004 Jan;30(1):26-32

"Two slipped flaps and 20 cases of interface inflammation occurred early in the series".