The infratrochlear nerve is a division of the nasociliary nerve and emerges nearby the anterior ethmoidal foramen. It travels along the medial wall of the orbit prior leaving over the medial canthus. The infratrochlear nerve also laterally obtains a branch from the supratrochlear nerve.
The nerve travels inferiorly and innervates
- Medial eyelid
- Lateral part of the nose above the medial canthus
- Medial conjunctiva
- Lacrimal apparatus
The infratrochlear nerve innervates the skin of the upper nasal vault. This nerve is blocked by penetration of anesthetic medial towards the medial canthus, underneath the thin skin of the lateral bony nasal sidewall.