Inferior oblique underaction: A transient complication related to inferior orbital wall fracture in childhood

Purpose: To evaluate inferior oblique (IO) underaction related to orbital floor fracture and its management. Methods: We retrospectively assessed 137 patients with orbital floor fractures who had undergone surgical repair between July 2003 and August 2009. Review of clinical data, which included photographs and radiologic findings, was performed. IO underaction was diagnosed based on anomalous head position and which was confirmed with the Hess test and limitation of duction and version in the nine diagnostic positions of gaze. Results: Twelve patients demonstrated IO underaction pattern (8.8%); 3 patients presented preoperatively and 9 patients presented postoperatively. All the patients showed IO underaction pattern in the Hess test and head tilt position. The median age was 9.5 years (range, 6-24 years), and all the patients were male. Of 12 patients, 10 (85%) presented with nausea and vomiting symptoms, 2 (17%) infraorbital hypoesthesia, and 3 (25%) pupillary dilatation. On the basis of the CT scans, all patients had trap door fractures with soft tissue entrapment. The IO underaction recovered spontaneously within 2 months without any treatment. Conclusion: Head tilt towards the injured side can be a warning sign of IO underaction in orbital floor fracture, especially pre- or postoperatively in the paediatric population. Physicians managing paediatric orbital fracture should be aware of this transient complication.