Restrictive Limitation of Sursumduction Caused by an Anomalous Muscular Structure

We report a peculiar case of congenitally restricted sursumduction caused by an anomalous band-like structure within the right orbit which was completely distinct from the extraocular muscles. Imaging (static and dynamic ultrasound studies of the orbit and globe, CT and MRI) revealed the origin of the anomalous structure in Zinn's ring, its intraconal course and bulbar insertion. The ultrasound characteristics were similar to those of the...