It is not unusual for recurrent polyps or papillomatous sinus disease to lead to dehissance of the Lamina Papyrecea.  The Anterior Ethmoid Artery is in close proximitry to this region and injury is possible.  I have probably done as many sinus surgeries as anyone alive and kind of felt that my super human skills left me immune to this complication, until now.  The intranasal surgery showed little sign of any problem, but the exposed eye become immediately proptotic and tense.