optokinetic reflex
Pronunciation: op-toe-ki-NET-ik
Also written as: OKR — optokinetic reflex
An involuntary eye movement response to large-field moving visual stimuli, consisting of slow pursuit followed by fast resetting movements.
Full Definition
The optokinetic reflex (OKR) is a primitive visual-vestibular reflex that stabilizes images on the retina during sustained rotation or when viewing repetitive moving patterns. The response consists of slow pursuit movements in the direction of target motion followed by rapid corrective saccades in the opposite direction. This creates a characteristic sawtooth pattern of eye movements. The reflex is mediated by subcortical pathways and can be elicited even in cortically blind patients, making it useful for assessing visual function in non-responsive patients or infants.
Usage
Usage note: Commonly abbreviated as OKR; distinguish from optokinetic nystagmus which refers specifically to the nystagmus component.
In Context
- "Optokinetic reflex testing revealed asymmetric responses with impaired rightward slow phases." — Pediatric visual assessment
- "The presence of robust optokinetic reflexes suggested intact visual pathways despite the patient's inability to respond verbally." — Comatose patient evaluation