Anisocoria and Afferent Pupillary Defects

Modern authoritative sources, in contrast to Behr, assert that lesions of the anterior visual pathways do not result in anisocoria. Attempts to induce such anisocoria have failed. Otto Lowenstein clearly stated 'Clinically, anisocoria is frequently observed in cases with lesions in the optic nerve, chiasm, or tract. This, however, cannot be caused by unequal distribution of afferent impulses due to a lesion in the first neuron.' The purpose of the present investigation is to prospectively ascertain if a relationship exists between anisocoria and damage to the anterior visual pathways.