A 47-year-old woman, physically active, presented with a history of progressive isolated right eye visual loss (20/200). Ophtalmological examination with Goldmann's perimetry showed a Marcus Gunn pupil, an optic disc temporal pallor and a central scotoma on the affected eye. CT scan and cerebral angiography demonstrated an abnormally wide and elongated (megadolichoectatic) intraorbital ophthalmic artery responsible for optic nerve compression in the optic canal. Pulse steroid therapy was chosen and allowed recuperation of right eye visual acuity to 20/20. A 3-months' follow-up was decided and to date, 1 year later, she fell back to 20/40 with a normal right eye visual field. The authors compare these clinical and radiological findings with intraorbital aneurysms and discuss the therapeutic options for this extremely rare form of vascular disease.