The Corneal Reflex
February 15th, 2021
Overview
How to Elicit
- Lightly touch the cornea with a piece of cotton wool. Approach from the side so that the patient does not anticipate the stimulus.
Causes of Absent Corneal Reflex
- Upper motor neuron lesion - pons or medullary infarction, tumour or haemorrhage
- Facial nerve (VII) lesion - Bell's palsy, infection, inflammation, tumour, trauma
- Ophthalmic nerve (V1) lesion - trauma, tumour, ICA aneurysm, cavernous sinus thrombosis, SLE
Interpretation
- No direct response - absent blink in the tested eyeIpsilateral facial nerve (VII) lesion
- No consensual response - absent blink in the opposite eyeContralateral facial nerve (VII) lesion
- No afferent response - absent blink in one eye when testing either eyeIpsilateral ophthalmic nerve (V1) lesion
- No response - absent blink in both eyes when testing either eyePons or medullary lesion
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