Session: Poster session C

Surgical repair of complete inferior rectus muscle transection following non-penetrating trauma: a case report

Introduction

Transection of any extraocular muscle (EOM) without globe, eyelid, or orbital bone involvement is rare. We report an unusual case of isolated inferior rectus (IR) muscle transection and demonstrate good post-operative outcomes with early intervention.

 

Case report

A 47-year-old male with childhood surgical correction of congenital esotropia presented following left eye injury with pliers, complaining of pain and diplopia. On examination, his vision was 6/15 (6/7.5 with pinhole). There was visible soft tissue protruding through an inferior conjunctival laceration, and marked left hypertropia, with -3 infraduction deficit. No other abnormalities were found. CT orbits showed no fractures or globe rupture.

 

Inferior peritomy performed during emergency surgical exploration confirmed a horizontally transected IR. The anterior aspect of the IR retained its insertion 6.5 mm from limbus, the posterior slipped part of the IR was identified inferiorly attached to Tenon’s and both parts joined using 6/0 vicryl sutures. Exploration revealed intact sclera and globe. At 3-months post-operatively, there was no overt diplopia, good VA (6/4), but residual -2 underactivity of infraduction, correctable with 2D base-down Fresnel prism.

 

Discussion

Traumatic IR injuries frequently occur associated with orbital floor fractures or globe injury; only 3 other cases of isolated traumatic IR transection were identified in the literature. Most of these patients ultimately achieved orthotropia or microtropia. Some authors suggest delaying surgical repair for up to 6 months to observe for spontaneous resolution, whilst other cases of delayed repair had poor outcomes due to fibrosis.

 

Conclusion

Isolated EOM transection without globe or orbit injury is rare, however should be considered in all trauma cases presenting with diplopia. This case of isolated IR transection expands the limited evidence base and demonstrates that good functional outcome can be achieved with prompt surgical repair.