Supratrochlear artery

The supratrochlear artery (or frontal artery) is one of the terminal branches of the ophthalmic artery. It branches from the ophthalmic artery near the trochlea of the superior oblique muscle in the orbit.
Pathway.
The supratrochlear artery branches from the ophthalmic artery and passes anteriorly through the superomedial orbit. It travels medial to the trochlear nerve. With the supratrochlear nerve, the supratrochlear artery exits the orbit through the supratrochlear notch (variably present), medial to the supraorbital foramen and its artery and nerve. It then ascends on the forehead. 
The supratrochlear artery anastomoses with the ipsilateral supraorbital artery and contralateral supratrochlear artery. Since the supratrochlear artery is an ultimate branch of the internal carotid artery, this is an example of an internal carotid artery - external carotid artery anastomosis.
Function.
The supratrochlear artery supplies blood to the skin of the medial aspect of the forehead and scalp, as well as the underlying pericranium and frontalis muscle.
External links.
https://radiopaedia.org/articles/supratrochlear-artery