[Normotensive glaucoma].

Normal tension glaucoma is a form of primary open angle glaucoma where the intraocular pressure remains within the normal range. In this case the main challenge is to establish the correct diagnosis. The clinical evaluation of a patient suspected of a normal tension glaucoma must answer two questions: 1) is the intraocular pressure normal and 2) is it a glaucomatous optic neuropathy or another type of optic neuropathy?