We present a case of a 36-year-old man who developed rapid onset of proptosis and orbital compartment syndrome resulting in no light perception vision. He was treated with surgery and subsequent rituximab therapy with some recovery of vision and motility. Though the range of presentations of idiopathic orbital inflammation is broad, such rapid evolution of proptosis with complete vision loss is very uncommon.
Keywords: Chronic nongranulomatous inflammation; idiopathic orbital inflammation; orbital compartment syndrome; orbital decompression; proptosis; vision loss.