A 69-year-old woman was admitted for asthenia and fatigue in the course of an outbreak of temporal arteritis on maintenance treatment with glucocorticoids.
She consulted the ophthalmologist urgently due to decreased visual acuity (VA), pain, tearing and difficulty opening the eyelids of the right eye (OD), associated with ipsilateral exophthalmos of uncertain onset.
VA was 0.3 in the OD and 0.6 in the left eye (LA) with a relative afferent pupillary defect of 3+/4+ in the OD. There was mild conjunctival hyperemia, restriction of suprathreshold translations in the OD with vertical diplopia and mild ipsilateral exophthalmos with oedematous eyelids under tension. Intraocular pressure (IOP) was 15 mmHg and 17 mmHg in OD suprathreshold and 14 mmHg in OI. The macula was normal and the papilla had no oedema or pallor.

Two months earlier, the VA was 0.8 in both eyes with incipient cataracts.
In view of this clinical picture, an urgent orbital CT scan was requested, showing thickening without a clear spindle shape of the inferior rectus and lateral rectus muscles of the right eye, especially in the distal two thirds, with a slight increase in orbital fat, as well as occupation of the posterior ethmoidal cells and the pterygomaxillary fossa.

It was decided to start treatment with methylprednisolone 250 mg intravenous every 6 hours for 3 days. The patient was evaluated 2 days later and reported significant improvement. A concentric reduction in the visual field was observed, which subsequently returned to normal.

After eight months, the VA of the OD after cataract surgery is unity, with normal pupillary reflexes and no papillary pallor. CT and MRI showed a non-specific occupation of the pterygopalatine fossa and orbital apex with slight distal thickening of the inferior rectus and lateral rectus muscles compatible with orbital pseudotumour.

