Abstract and Introduction
Abstract
Accurate detection and interpretation of eye movement abnormalities often guides differential diagnosis, discussions on prognosis and disease mechanisms, and directed treatment of disabling visual symptoms and signs. A comprehensive clinical eye movement examination is high yield from a diagnostic standpoint; however, skillful recording and quantification of eye movements can increase detection of subclinical deficits, confirm clinical suspicions, guide therapeutics, and generate expansive research opportunities. This review encompasses an overview of the clinical eye movement examination, provides examples of practical diagnostic contributions from quantitative recordings of eye movements, and comments on recording equipment and related challenges.
Introduction
Accurate detection and interpretation of eye movement abnormalities in clinical neurology often guides differential diagnosis, contributes to discussions of prognosis and disease mechanisms, and allows for directed treatment of disabling visual symptoms and signs such as diplopia and oscillopsia (i.e., a subjective sense of visual motion). Although performance of a comprehensive clinical eye movement examination is high yield from a diagnostic standpoint, quantitative eye movement recordings provide a powerful complement. Technology leveraged within the electrophysiologic domain increases the sensitivity to detect many clinical disorders. Neurology has embraced many diagnostic tools as 'gold standards' to supplement the clinical examination, such as automated visual field perimetry, which is more sensitive than confrontation visual fields,[1] and electromyography for confirmation of a clinical impression of peripheral neuropathy or myopathy. Similarly, recording and quantifying eye movements increases the detection sensitivity of subclinical deficits and confirms suspected clinical impressions to increase diagnostic accuracy.[2]
A vast scientific research literature exists for the purpose of documenting subclinical eye movement abnormalities in various diseases and applying eye movements as a research tool for the assessment of cognitive processing. While many of these findings might be considered by the practicing neurologist to be applicable mainly to research and lacking in practical clinical applications, we aim in this review to highlight examples of the immediate practical utility of eye movement recording and quantification. To do so, we intentionally keep terminology as simple as possible; in-depth and comprehensive reviews of ocular motor anatomy, and normal and abnormal ocular motor physiology may be found elsewhere.[2] We begin by reviewing a comprehensive bedside eye movement examination and then review how eye tracking can be used to record normal eye movements. We then turn our attention to examples of how quantitative eye movement recordings may impact diagnosis and treatment. We conclude with a brief section on types of available eye movement recording equipment and related challenges.
Semin Neurol. 2019;39(6):775-784. © 2019 Thieme Medical Publishers
