A 42-year-old male patient of yours presents to your clinic on an urgent basis for decreasing vision and “protrusion” of his left eye. The patient says that over the last 48-72 hours he has noticed increasing proptosis, decreased vision, and pain of his left eye. Yesterday he had diplopia, although no longer has it today. He has especially noticed vision decreasing the last several hours. He feels unwell with fever, chills, and rigors. He has a long history of sinusitis and also has poorly controlled diabetes mellitus.
External examination of the patient is shown below. The left periorbital area is warm, tense, and severely swollen. There is conjunctival chemosis and obvious left sided proptosis. Visual acuity is counting fingers (previous exam 20/20) with a relative afferent pupillary defect. Extraocular movements are impaired in all directions of gaze. Intraocular pressure is measured at 65.