The images were obtained retrospectively from a departmental SD-OCT database and medical records. The images included one eye each from 75 subjects: 25 with papilledema and intracranial hypertension, 20 with nonarteritic anterior ischemic optic neuropathy (AION), and 30 with clinically normal optic discs. The right eye was used in all subjects with papilledema and normals. If the left eye was affected in subjects with AION, the image was flipped horizontally to align the temporal and nasal regions across all subjects. The diagnosis of papilledema was based on generally accepted clinical funduscopic features, including elevation, blurring of the margins, vascular engorgement, circumpapillary folds, and hemorrhages. All subjects with papilledema had opening pressures of >250 mm water and SD-OCT evidence of average RNFL thickening (>95% of the normal controls, by Cirrus HD SD-OCT,). Twenty-three of the papilledema subjects had idiopathic intracranial hypertension (21 women, 2 men): One patient had a venous sinus thrombosis and the other a large frontal lobe meningioma. Among subjects with normal optic discs, we excluded those with clinically abnormal acuity, color vision, pupillary findings, intraocular pressure, visual fields, and ophthalmoscopic findings or SD-OCT evidence of an optic neuropathy, optic atrophy, glaucoma or congenital disc anomalies (e.g., drusen, hypoplasia, oblique insertion, tilting, high myopia, staphylomas or otherwise dysplastic). This study was approved by the SUNY Stony Brook Committee on Research Involving Human Subjects and complied with the Declaration of Helsinki.