Exam

Corneal Reflex

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Corneal Reflex, Cornea Reflex, Blink Reflex

  • Indications
  1. Brainstem function testing in coma
  • Mechanism
  1. Afferent limb: Touch stimulates the V1 branch of the Trigeminal Nerve (Cranial Nerve 5)
  2. Reflex center: Pons in the Brainstem
  3. Efferent limb: Temporal and zygomatic arches of the Facial Nerve (Cranial Nerve 7) close the Eyelids
  • Technique
  1. Touch Cornea, lid or Conjunctiva with cotton whisp
  2. Alternative: Instill 5-10 cc Normal Saline by syringe over the surface of the Cornea
  • Interpretation
  • Expected response (normal)
  1. Results in a rapid, Blink Reflex in the exposed eye as well as the other eye (consensual response)
  2. Diminished reflex in those who use Contact Lenses
  3. Intact reflex suggests intact Brainstem function
  • Resources
  1. Corneal Light Reflex at wikipedia
    1. http://en.wikipedia.org/wiki/Corneal_reflex
  • References
  1. Degowin (1987) Diagnostic Examination, 5th ed, MacMillan Publishing Company, p. 810