Glaucomatous Type Cupping Caused by Internal Carotid Artery Compression: a Case Report.

A 71-year-old woman with a diagnosis of normal tension glaucoma (NTG) presented with complains of progressive visual loss in the right eye. Examination revealed features consistent with compressive optic neuropathy. Although brain magnetic resonance imaging (MRI) was initially interpreted as normal, re-evaluation disclosed a compression on the right optic nerve from the right internal carotid artery. We highlight the clinical differential diagnosis between NTG and compressive optic neuropathy. This case is a reminder that a compressive optic neuropathy may be caused by anatomical variation of normal intracranial structures.