Knapp Christopher M, Proudlock Frank A, Gottlob Irene
Department of Ophthalmology, Lincoln County Hospital, Lincolnshire, UK.
Strabismus. 2013 Mar;21(1):37-49. doi: 10.3109/09273972.2012.762532.
Optokinetic nystagmus (OKN) is a reflex eye movement induced by motion of the whole or a large proportion of the visual field. It can be horizontal, vertical, and torsional in direction and consists of two basic components, a slow tracking movement and a rapid recovery saccade. Two forms of OKN exist: "look" and "stare" OKN. There is strong evidence that horizontal OKN is symmetrical in normal healthy adults and that the OKN gains can be influenced by a variety of different factors including target size, shape, contrast, and velocity. Vertical OKN on the other hand is less well understood, although there is a belief that vertical OKN is asymmetrical with an upward preference. Recent publications contradict this assertion. In this article a comprehensive literature review was carried out to determine whether a vertical OKN asymmetry exists in healthy subjects and to explain any anomalous findings.
视动性眼震（OKN）是由整个或大部分视野的运动诱发的一种反射性眼球运动。其方向可以是水平、垂直和扭转的，由两个基本成分组成，即缓慢跟踪运动和快速恢复扫视。OKN有两种形式：“注视”和“凝视”OKN。有强有力的证据表明，正常健康成年人的水平OKN是对称的，并且OKN增益会受到多种不同因素的影响，包括目标大小、形状、对比度和速度。另一方面，垂直OKN的情况则了解较少，尽管有人认为垂直OKN是不对称的，且向上的倾向更明显。最近的出版物与这一观点相矛盾。在本文中，进行了全面的文献综述，以确定健康受试者中是否存在垂直OKN不对称现象，并解释任何异常发现。
