Frontal sinus pneumocoele: a rare cause of orbital emphysema.

Sudden onset nonaxial proptosis and diplopia is alarming and orbital haemorrhage or a rapidly expanding orbital tumour should be excluded. We present a case of a young man aged 15 years who attended the Accident and Emergency Department with a 6-h history of sudden onset proptosis and diplopia in whom the aetiology was orbital emphysema.