Significance of Vascular Notching of Optic Nerves and Chiasm on Visual Disturbance

Abstract

The authors have reported five cases of pituitary tumors with notching of the optic nerves and chiasm caused by the overlying anterior cerebral arteries observed under the operating microscope.
Extension of the pituitary tumor seems to push the optic nerves and chiasm upward against the anterior cerebral arteries, producing transverse notching on their surface.
We suggest that this notching is responsible for visual field defects and loss of visual acuity in some cases of pituitary tumor. The possible pathophysiological mechanisms of this phenomenon are also discussed in detail.