Cauterization-mediated restriction from penetrating orbital trauma.

A healthy 32-year-old woman presented with binocular diplopia immediately after sustaining a penetrating injury to the left periocular adnexa with a hot metal skewer. Examination revealed an incomitant esotropia, with complete limitation of abduction of the left eye with downshoot in left gaze and normal afferent visual function. Computed tomography and magnetic resonance imaging demonstrated no fracture, but there was mild thickening of the medial rectus muscle and associated fat stranding. Lack of orbitomuscular tethering or hematoma led to the presumptive diagnosis of thermal cauterization injury causing left medial rectus restriction. Given the lack of literature on this mechanism of injury, the patient was monitored closely. She exhibited remarkable spontaneous improvement in motility over 6 months, with near orthophoria in primary gaze. However, bothersome residual esotropic diplopia in left gaze prompted a left medial rectus recession, with a good outcome. This case demonstrates that isolated extraocular muscle thermal injuries and consequential strabismus can recover spontaneously; longitudinal observation before surgical intervention may be appropriate in such cases.