To present 6 cases of orbital trauma diplopia and strabismus after functional endoscopic sinus surgeries (FESS).

Retrospective observational case series. The medical charts of suitable patients were reviewed for information on medical examination, imaging studies, the type of corrective surgery, and surgical outcomes. All patients with diplopia and strabismus after undergoing FESS who were treated or consulted at our institution between 2008 and 2017 were included. Main Outcome Measures were the presence and extent of strabismus and double vision at the end of follow up.

Six patients complained of diplopia after FESS, all of them had proven orbital trauma. Cases 1-5 suffered medial rectus (MR) muscle transection and subsequent exotropia. Their prognosis was guarded despite prompt surgical intervention, and ranged from large exotropia when direct recovery of the MR was attempted, to primary gaze orthotropia but with minimal adduction capacity during which vertical recti transposition was attempted. Patient 6 sustained transient diplopia although all of his extraocular muscles appeared intact on imaging. His eye position and movement were completely resolved with conservative measures only.

Our experience was that immediate recovery procedures to reattach the muscle in cases with proven transection of the MR muscle are futile, and that definitive corrective strabismus surgery, i.e. vertical muscle transposition have a better chance to achieve favorable results.