Is endoscopic optic nerve decompression useful in cases of optic neuropathy secondary to pachymeningitis?

This case reports the outcome of endoscopic optic nerve decompression in a rare case of idiopathic pachymeningitis in a patient solely reliant on the affected eye. A 70 year old man with complete blindness in his left eye presented with deterioration of vision in his right eye. An MRI head and orbits was suggestive of idiopathic pachymeningitis extending into the right orbital apex, causing a compressive optic neuropathy. He subsequently underwent endoscopic optic nerve compression. Visual acuity and colour vision were measured pre-operatively, and at 6 weeks and one year post operatively. Pre-operative visual acuity was measured at 6/9, compared to 6/9 at 6 weeks post operatively and 6/60 at one year. Colour vision was measured at 0/17 pre-operatively and did not improve post-. We report a rare case of optic neuropathy secondary to pachymeningitis, in which endoscopic nerve decompression did not offer the expected benefit of halting visual deterioration.