Corneal reflex

The corneal reflex that is dependent on the integrity of the Vth and the VIIth cranial nerves.

Method:

• distract the patient by asking them to gaze upwards.
• lightly touch the cornea using a moistened cotton tip, bringing it in very carefully from the side of the eye. (Using conventional dry cotton wool carries a risk of corneal abrasion if done improperly).
• applying sterile normal saline drops directly to the eye is also a safe, atraumatic method to test the corneal blink reflex in unresponsive or sedated patients

Interpretation of results:

• reflex blinking of both eyes - normal
• patient can feel the touch of the cotton wool - via the ophthalmic division of the trigeminal nerve - but there is no reflex blink - via facial nerve innervation of orbicularis oculi muscles. This indicates facial nerve palsy.
• unable to feel touch of cotton wool - indicates trigeminal nerve palsy.