A 24-year-old woman experienced acute loss of vision in her left eye over several days. She reported ipsilateral pain with eye movement. Examination revealed an acuity of 20/200, a ceco-central scotoma, and an afferent pupillary defect OS. Note that the acute disc swelling in this case is associated with a mild hyperemia and a splinter hemorrhage at 5:30. Paton's lines can be appreciated adjacent to the temporal disc margin (retinal folds).