See-saw nystagmus is a form of disjunctive nystagmus in which 1 eye elevates and intorts while the other eye depresses and extorts, a movement reminiscent of that of a see-saw. The eye movements are typically pendular, slow in frequency, and similar in amplitude between eyes. See-saw nystagmus may be congenital or acquired and may be caused by lesions that affect the chiasm, midbrain, or both. Trauma and parasellar-diencephalic tumors, in particular craniopharyngioma, are frequent causes; hydrocephalus and congenital achiasma are rare causes. There may be associated vision loss, often a bitemporal hemianopia. See-saw nystagmus may also occur in patients with vision loss due to retinitis pigmentosa, albinism, or optic nerve hypoplasia. Asymmetric vision loss may influence the amplitude of the eye movements (ie, the amplitude may be larger in the eye with poorer vision).
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.