Infratrochlear nerve

The infratrochlear nerve is an extraconal branch of the nasociliary nerve, a branch of ophthalmic division of the trigeminal nerve. Some authors describe it as the terminal branch of the nasociliary nerve. It courses through the medial aspect of the extraconal space of the orbit inferior to the trochlea and exits the orbit under the superior orbital margin medially to supply the conjunctiva of the medial upper eyelid and medial canthus, the lacrimal sac and caruncle and the skin of the bridge of the nose.