Slit-like defects in the peripapillary nerve fiber layer and corollary defects in the field of vision occur frequently in multiple sclerosis, often before there is a change in the patient's visual acuity, color perception, or optic disc. These subtle ophthalmoscopic signs indicate scattered attrition of axon bundles by lesions in the anterior visual pathway. The appearances of such defects in the retinal nerve fiber layer are described and exemplified photographically in case reports of two young adults, one with symptoms of spinal cord disease and the other with a brain stem syndrome.
Frisén L, Hoyt WF. Insidious Atrophy of Retinal Nerve Fibers in Multiple SclerosisFunduscopic Identification in Patients With and Without Visual Complaints. Arch Ophthalmol. 1974;92(2):91-97. doi:10.1001/archopht.1974.01010010097001