Optic nerve compression by the internal carotid artery in patients with normal tension and high tension glaucoma

E ditor ,-It is generally accepted that ectatic or even normal intracranial blood vessels can cause dysfunction of cranial nerves when situated in an aberrant location. 1-3 Although the occurrence of such compression damage to the optic nerve is poorly recognised, several studies have shown the optic nerves can in fact be damaged by vascular compression. 4-8 Recently, optic nerve compression by normal internal carotid arteries (ICA) has been suggested as a possible cause of visual field defects in patients with optic neuropathy 4-6 and normal tension glaucoma (NTG). [...]25% of our NTG patients did not show vascular compression, and almost half of the control HTG patients also had vascular compression. [...]there was no statistically significant difference in the clinical characteristics of the eyes with optic nerve compression compared with those without.