Slow conjugate eye movements: Normative data for routine diagnosis of ophthalmo-neurological disorders

Abstract

With regard to the use of slow conjugate eye movements in the diagnosis of ophthalmo-neurological disorders, the suitability of various stimulus parameters for routine examinations was evaluated and normative data were obtained with Infrared-Reflection-Oculography (IROG) from 21 healthy subjects. Sinusoidal and for smooth pursuit, additionally triangular stimuli were used at various frequencies for visual as well as for vestibular stimulation with a constant amplitude of 30 degrees (± 15 deg). Sinusoidal stimulus presentation proved to be more adequate for examining smooth pursuit than triangular. For smooth pursuit and vestibulo-ocular reflex suppression (VORS) stimulus frequencies up to 0.5 Hz appeared to be most suitable for routine examinations. Normative data were also obtained for a simple VORS test consisting of manual back and forth rotation of the subjects' head by the examiner. Examinations of the vestibulo-ocular reflex (VOR) and of the visual VOR (VVOR) are recommended for particular clinical questions. Although the age distribution of our subjects was homogeneous between eight and 74 years, the authors could not find an age dependence for any of the slow eye movement parameters.

Key Words:

• slow conjugate eye movements
• infrared reflection oculography (IROG)
• normative data
• smooth pursuit
• vestibulo-ocular reflex suppression (VORS)
• vestibulo-ocular reflex (VOR)
• visual VOR (VVOR)