Surgical management of persistent diplopia in blowout fractures of the orbit.

Persistent diplopia continues as a problem in a significant number of patients following the surgical management of a blowout fracture of the orbital floor even when repaired within 15 days of the traumatic incident. Inferior rectus and inferior oblique muscles which have been incarcerated in a blowout fracture for longer periods have a worse prognosis for adequate functioning postoperatively. There is some presumptive evidence to suggest a myogenic or neurogenic cause for such dysfunction. Experiments with posterior fractures clearly demonstrate that the nerve entering the inferior rectus can be damaged. Vertical diplopia which persists beyond 3 months following release of entrapped muscle tissue requires surgical correction depending upon the degree of vertical dissociation. Motility surgery was required in 18 of 20 patients with persistent diplopia. Multiple muscle combinations were frequently required to achieve success. The criterion for a successful result was elimination of vertical diplopia in the primary and reading position. The elimination of persistent diplopia in association with blowout fractures of the orbit is usually possible even in late treated cases when one uses specific criteria for success. Three cases were considered cured since there was no diplopia in any direction of gaze, while 17 cases developed single binocular vision in the primary and reading positions. In these latter patients, on extreme upward or downward gaze, diplopia could still be demonstrated in all patients, especially when the individuals were specifically requested to look for diplopia.