A 31-year-old male presented with a history of gradually increasing proptosis and progressive loss of vision in the left eye for the last 6 months. The patient had no nasal symptoms of discharge or obstruction. An orbital biopsy through an external route was taken elsewhere 25 days ago and was found to be inconclusive. At the time of presentation, he had severe conjunctival congestion with severe chemosis grade 3 and lagophthalmos and visual acuity limited to counting fingers at 1 m.