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Oculocardiac reflex (OCR), also known as the Aschner reflex or trigeminovagal reflex (TVR), is a reflux resulting in severe bradycardia (decrease in heart rate (HR) of > 20%) caused by traction applied to the extraocular muscles (especially the medial rectus muscle), pressure on the globe, ocular trauma, traction on the conjunctiva, or occasionally by placement of a retrobulbar block.
- Rate of OCR occurrence rate in ophthalmologic surgeries: 63-68%
Physiology
- Afferent stimulus via ophthalmic branch of cranial nerve V (trigeminal nerve)
- Efferent stimulus via cranial nerve X (vagus nerve)

OCR pathway:
The afferent OCR limb is via the long ciliary nerve and the short ciliary nerves. The latter first come together at the ciliary ganglion; these two inputs then converge to form the ophthalmic division of the trigeminal nerve. The efferent limb of the OCR is vagal via the cardiac depressor nerve.

Clinical features
- Sinus bradycardia (M/C)
- Hypotension
- Atrioventricular block
- Ventricular ectopy
- Asystole (rare)
Management
- Immediate cessation of the stimuli
- If the reflex recurs:
- IV atropine (glycopyrrolate likely will not provide a strong enough anticholinergic boost) or lidocaine infiltration of the extraocular muscles
- Severely decreased CO and hypotension:
- IV epinephrine or external pacing