Visual diagnosis in emergency

medicine: retrobulbar haemorrhage An elderly patient on Coumadin presented to the emergency department one day after left eye surgery. She complained of orbital pain and vision loss. On examination there was eyelid ecchymoses, chemosis and proptosis (figure 1). There was com-plete vision loss with preservation of light sense. The patient went to the operating room for emergent decompressive surgery. She regained full vision in her eye. DIAGNOSIS: RETROBULBAR HAEMORRHAGE Retrobulbar haemorrhage is a vision-threatening emergency. It is typically secondary to facial trauma or a surgical procedure. Without prompt recognition and treatment, the haemorrhage can expand and produce an orbital compartment syndrome. In orbital compartment syndrome, high intraocular pressure (IOP) damages the optic nerve and compromises vascular flow, result-ing in retinal ischaemia.1 Total vascular insufficiency of only 60–120 min can produce permanent vision loss.2 Signs and symptoms indicative of high IOP may include painful proptosis, a difference in globe compressibility, ophthal-moplegia, double vision, decreased visual acuity, decreased pupil responsiveness, cherry red macula and nerve head pallor.3 CT scan or MRI of the orbit may help to identify the aetiology of compression, when the diagnosis is unclear. Immediate orbital decompression is indicated with an IOP>40 mm Hg, a marked difference in globe compressibility, proptosis or any decreased visual acuity. Lateral canthotomy with cantholysis is recommended as first-line treatment in these cases.3 Medical management with Acetazolamide and Timolol can be used as adjuncts to decompression. If vision fails to improve, surgical evacuation of the intraorbital haematoma should be undertaken.