In order to make a definitive diagnosis, ischemic optic neuropathy needs to be excluded in patients with normal IOP glaucoma. Normal IOP glaucoma patients are those who have limited visual field defects and optic nerve atrophy, but do not have pathologically elevated intraocular pressure, and their performance is very similar to that of ischemic optic neuropathy, so in order to avoid a misdiagnosis, further examination should be performed to identify the two. In terms of symptoms, ischemic optic neuropathy has a more sudden onset, whereas patients with normal IOP glaucoma have a slower onset. On examination, patients with ischemic neuropathy may have areas of hypofluorescence in the optic nerve on fundus fluorescence angiography, whereas patients with normal IOP glaucoma do not. These differences in presentation usually allow the two to be differentiated. It is recommended that patients with normal IOP glaucoma be seen in a timely manner to have their condition evaluated and treated as prescribed by their physician.