Abnormal Eye Movements in Children

Abstract

The recognition and evaluation of abnormal eye movements in children is an essential task for the pediatric ophthalmologist that may lead to the discovery of systemic and neurologic disease and even preventable visual loss. With few exceptions, the eye movements discussed in this chapter can occur at all stages of life, but their presentation in infancy and childhood has a unique significance that merits their inclusion in this textbook on pediatric manifestations of ophthalmic disease. The first step in approaching abnormal eye movements is to categorize them into broad categories, such as ‘‘roving’’ eye movements that are commonly seen in patients who develop visual-impairment early in life, saccadic intrusions (see below), or the true forms of nystagmus. With a cursory examination, these manifestations of ocular motor pathology may be confused, but each has its own implications for diagnosis and management. Roving eye movements are very slow, large amplitude, and seemingly aimless movements of the eyes that are seen in patients who are severely blind early in life. Saccadic intrusions are relatively fast, conjugate eye movements of relatively small amplitude that often occur in short bursts or as single events. Saccadic intrusions may occur as back-andforth movements across the point of fixation (ie, ‘‘saccadic oscillations’’), or as equal amplitude movements off to one side and then back onto the point of fixation (ie, ‘‘square-wave jerks’’). For both types of saccadic intrusions, there is an almost imperceptible delay between one saccadic movement and the next (ie, intersaccadic interval). In distinction,