**Abstract**

Optic nerve can be affected by various etiologies of optic neuropathies, and it can appear swollen or pale depending on etiology and duration of the disease. These etiologies are inflammation, ischemia, malignancy, idiopathic intracranial hypertension, toxins, and nutritional deficiency. Peripapillary optical coherence tomography (OCT) is widely performed to detect these diseases and monitor them based on the changes in peripapillary retinal nerve fiber layer (RNFL) thickness. Therefore, nowadays this modality of imaging has become a routine test in follow-up of optic nerve diseases. In this chapter, clinical examinations and main findings of peripapillary OCT in common optic neuropathies are discussed.

**Keywords:** optic nerve head, optic disc, optic neuropathies, peripapillary, optical coherence tomography, retinal nerve fiber layer
