The corneal reflex test (blink test) examines the reflex pathway involving cranial nerves V and VII. Classically the provider lightly touches a wisp of cotton on the patient's cornea. This foreign body sensation should cause the patient to reflexively blink.
This maneuver always makes me a little worried about causing a corneal abrasion, especially if you are examining a very somnolent patient. You are wondering -- Is there no blinking because you're not touching the cornea hard enough? You apply harder pressure but still no blink. You repeat the test and now the patient finally blinks. That's 3 times you've just scraped against the cornea.
What's an alternative approach?
Apply drops of sterile saline on the eye.
When a patient presents with a low GCS, you want to perform rapid neurologic exam. I've been seeing our neurologists do a quick simple test for corneal reflexes. Grab a pre-filled sterile saline syringe, typically used to flush IV's, and squirt a few drops on the eye. Look for the patient to blink.
This seems much safer and definitive of a test of the corneal reflex.
nice, michelle- i like!
ReplyDeletegood one
ReplyDeletethanks
Happy to share with colleagues in NY and Qatar!
ReplyDeletethe saline solution will inevitably touch the eyelashes causing the patient to blink.
ReplyDeleteso, this method is not accurate
The majority of the solution still contacts the cornea while you keep the upper eyelid lifted during the reflex testing. I think it's still an accurate test. Our neurologists use it all the time.
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