A type of open-angle glaucoma (see also primary open-angle glaucoma) presenting within normal range for intraocular pressure (IOP). Etiology is uncertain, but theories point to vascular insufficiency and structural anomalies of the optic nerve, and the possibility of optic nerve sensitivity to seemingly normal intraocular pressure. A familial inherited predisposition has been identified, particularly in patients of Japanese descent. Risk factors include ischemic disease (diabetes, stroke) and vasospastic conditions (migraine headache, Raynaud phenomenon). Characterized by loss of retinal fiber or peripapillary atrophy around the optic rim, cupping of the optic nerve head, small Drance hemorrhages, and most notably, progressive visual field loss in the absence of increased IOP. Usually asymptomatic until reaching advanced stages; sometimes presents with early scotoma.

Patients with an optic neuropathy who have normal pressure require ongoing monitoring. Management includes the use of medications, laser trabeculoplasty, and surgery.