Corneal Reflex

Corneal reflex is mediated by the reflex arc that consists of exteroceptors of the cornea, the afferent ophthalmic nerve (1st branch of CN V) n. V. and the efferent from cranial nerve 7 innervating the orbicularis oris muscle m. orbicularis oculi. Reflex is elicited by a gentle touch of cotton wool on the cornea. We approach the obliquely from the side, while the patient looks to the other side (this avoids a defensive reaction mediated by sight). Blinking occurs physiologically after touching the cornea with the cotton wool.

The following common mistakes should be avoided during the examination:
 * The cotton swab should be on the conjunctiva instead of the cornea;
 * The touch of the cotton ball should be fast enough to induce a blink.

Video - Korneální reflex (Centrum elektronického vzdělávání 1.LF UK)

Complementary electrophysiological examination can distinguish between supra nuclear and peripheral localisation of a lesion.

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 * Postižení nervus trigeminus/PGS/diagnostika