Anatomical basis of the surgical approach to the medial wall of the orbit.

The main neurovascular structures related to the medial wall of the orbit were studied in 70 orbits after injection of the orbital arterial bed with latex dye. The position, anatomical relations and variations of the ophthalmic and ethmoidal arteries and trochlear and nasociliary nerves are described. Some differences were noted in comparison to classical anatomical descriptions, notably regarding the position of the ophthalmic artery which was commonly found to lie medial to the obliquus superior muscle distal to the point where it crosses under the muscle. An important surgical landmark, the lateral orifice of the anterior ethmoidal canal which lodges the anterior ethmoidal artery, was noted and its position described.