Pseudostrabismus Caused by Heterotopia of the Macula

Abstract

All of us are familiar with the relatively common pseudostrabismus caused by an exaggeration of the angle gamma or, as some prefer, angle kappa. In such cases, the alternate cover test quickly rules out the presence of an actual heterotropia, and the normal position of the blind spots in the visual fields rules out the presence of an anatomical anomaly. However, a condition does occur in which there is an actual physical derangement of the relationship of the blind spot, or optic papilla, to the macula. Idiopathic heterotopia of the macula is a very rare and interesting condition. It is typically manifested by eccentric fixation in an eye with good visual acuity and produces a confusing pseudostrabismus. The first report of this bizarre anomaly was that of Bernhard¹ in 1898. He recorded a case wherein the left eye appeared to be looking downward, when it was actually looking straight