A protocol for extraocular muscle surgery after orbital floor fracture ("blow-out").

Purpose: If, after primary repair of an orbital fracture by maxillo-facial surgeons, diplopia persists, extraocular muscle surgery may be necessary. It was the purpose of this study to examine proposed surgical treatment in these cases to determine their efficacy.

Subjects And Methods: We analyzed, retrospectively, the files of 14 patients who were treated in our strabismological department for persistent diplopia caused by injury to the extraocular muscles and/or to the surrounding structures. The aim of our treatment protocol was to restore comfortable binocular single vision in primary position and downgaze. The selection of the surgical procedure depended on the deviation in primary position and on the degree of ocular muscle imbalance. Surgery consisted of recession of the inferior rectus muscle of the affected eye in 4 cases, resection of the inferior rectus muscle of the affected eye in 4 other cases, and large recessions of the vertical muscles of the contralateral normal eye in 6 cases.

Results: In all 14 patients, we obtained the desired comfortable field of binocular single vision, considered "good" (20 degrees up to 30 degrees downgaze) or "satisfactory" (a useful field). In 11 cases this was achieved in one procedure. Two patients needed a reintervention because of initial overcorrection, and one patient for an initial undercorrection. All 14 patients had a "good" or "satisfactory" final result (useful binocular single vision).

Conclusions: When extraocular muscle surgery is necessary, we recommend in patients with limited forced elevation, recession of the taut rectus inferior muscle; in patients with the clinical characteristics of an inferior rectus palsy, a resection of this muscle; and in cases with a normal or only slightly limited forced duction test, weakening the contralateral synergists.