Silent threat of isolated sphenoid sinus tuberculosis resulting in blindness and ophthalmoplegia.

A diabetic woman in her fifties presented with a sudden onset of failing vision and diplopia involving the right eye for two days, along with fever and headache. Radiological investigations revealed right sphenoid sinusitis along with inflammation around the right orbital apex and optic nerve. Functional endoscopic sinus surgery, with orbital and optic nerve decompression improved the ocular movements, but not the visual acuity. Histopathology was suggestive of a granulomatous inflammatory lesion, and high-resolution computed tommography (HRCT) of the thorax revealed lung lesions suggestive of an old tubercular infection, and antitubercular treatment (ATT) was then initiated.At the end of two months of ATT, there was complete resolution of ophthalmoplegia, relative afferent pupillary defect, direct and consensual light reflex however, failure of improvement in her visual acuity, indicated damage to the optic nerve.Extrapulmonary tuberculosis involving an isolated sphenoid sinus is rare and elusive. Prompt radiological investigations, followed by orbital decompression and ATT, provide the best possible outcomes.