Purpose: To report a patient with medial rectus muscle entrapment as a complication of endoscopic dacryocystorhinostomy (EDCR).
Method: A 34 year old female was referred with diplopia 18 days after EDCR for the treatment of primary nasolacrimal duct obstruction. She had a large angle left exotropia in primary position as well as a complete limitation of adduction and partial limitation of abduction of left eye. CT scan showed large fracture of the medial orbital wall in which the medial rectus muscle was entrapped. She underwent multiple procedures in order to release the entrapped muscle as well as management of the diplopia .
Result: Finally the patient had 10 PD exotropia in primary position but could fuse with a small face turn.
Conclusion: Orbital wall fracture with medial rectus extraocular muscle entrapment as a complication of EDCR should be kept in mind.