Compressive optic neuropathy secondary to a pituitary macroadenoma]

Pituitary adenoma is a common benign tumor representing 8 to 10% of intracranial mass lesions. The compressive optic neuropathy associated with a pituitary adenoma can be clinically indistinguishable from glaucomatous optic neuropathy.A 56-year-old man with no significant past medical history had noticed a rapid decrease in visual acuity for 6 months. Funduscopic examination revealed glaucoma-like bilateral, asymmetric optic cupping. Brain MRI examination revealed a pituitary tumor compressing the optic chiasm.The diagnosis of a compressive optic neuropathy associated with a pituitary adenoma can be difficult, since it often simulates chronic glaucoma. However, several features should alert the clinician to the possibility of a compressive optic neuropathy and prompt neuroimaging, in order to obtain earlier diagnosis and treatment.