title: Surgical results of the slipped medial rectus muscle after hang back recession surgery.
abstract: OBJECTIVE
  To analyze the surgical results of a slipped medial rectus muscle (MRM) after hang back recession surgery for esotropia.
  
  
  METHODS
  Twenty-one patients who underwent re-exploration for diagnosed slipped muscle after hang back recession surgery were included in this retrospective study. Dynamic magnetic resonance imaging was performed to identify the location of the slipped muscle. Ocular motility was evaluated with assessment with prism and cover test in gaze at cardinal positions. The operations were performed by the same consultant. Intraoperative forced duction test was performed under general anesthesia. The empty sheath of the slipped MRM was resected and the muscle was advanced to the original insertion site in all patients.
  
  
  RESULTS
  The average age of 21 patients who had consecutive exotropia with a slipped MRM at the time of presentation was 17.4±5.4y (5-50y). The average duration between the first operation and the diagnosis of the slipped muscle was 25mo (12 to 36mo). The mean follow up after the corrective surgery was 28mo. The mean preoperative adduction limitation in the field of action of the slipped muscle was -2.26 (ranging from -1 to -4). All patients had full adduction postoperatively.
  
  
  CONCLUSIONS
  The diagnosis of the slipped muscle should be confirmed during the strabismus surgery. The slipped muscle may be caused due to insufficient suture and excessive rubbing of the eye. When divergent strabismus is observed after the recession of the MRM, a slipped muscle should be considered in the differential diagnosis.
authors.affiliation: Department of Ophthalmology, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey.
authors.forename: Yasar
authors.initials: Y
authors.lastname: Duranoglu
authors.affiliation: Department of Ophthalmology, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey.
authors.forename: Hatice Deniz
authors.initials: HD
authors.lastname: Ilhan
authors.affiliation: Department of Ophthalmology, Bor State Hospital, Nigde 51000, Turkey.
authors.forename: Meryem
authors.initials: M
authors.lastname: Guler Alis
keywords: empty sheath; esotropia; hang back recession; re-exploration; slipped muscle