Bilateral orbital haematomas in an anticoagulated patient with severe H1N1 influenza.

A previously healthy woman was admitted to the intensive care unit (ICU) with severe H1N1 influenza. She had prolonged hospital stay due to multiple complications of critical illness, including pelvic deep vein thrombosis (DVT), which was treated with subcutaneous enoxaparin. The patient was referred to the ophthalmology service for bilateral proptosis. On examination, she had bilateral tense proptosis, worse on the left side with exposure keratopathy. Laboratory tests showed that she had thrombocytopenia and raised activated partial thromboplastin time (APTT). A CT scan revealed well-circumscribed soft tissue density lesions in the superolateral orbits and was reported as bilateral lacrimal gland enlargement. However, based on a clinical suspicion of subperiosteal hematoma collection, a diagnostic tap was performed. Following aspiration of six mls of dark blood from the left superior orbit, there was a reduction of proptosis with improvement in chemosis and resolution of exposure keratopathy. Enoxaparin is one of several antithrombotic agents which are increasingly being used for DVT prophylaxis in severely compromised patients. Furthermore, ICU patients ventilated for prolonged periods are at risk of developing chemosis and exposure keratopathy. Thus, the clinician should maintain a high index of suspicion in identifying subperiosteal hematomas, when managing such cases. The spontaneous bilateral vision threatening subperiosteal hematoma was probably caused by a combination of enoxaparin therapy and prolonged ventilation.