Vertical strabismus resulting from an anomalous extraocular muscle

Unusual ocular motility abnormalities have been rarely reported to result from anomalous extraocular structures. These structures, which may be either muscular or fibrotic, attach to the globe and produce a mechanical restriction resulting in incomitant strabismus. To our knowledge, we report the first patient with an anomalous extraocular muscle in whom the clinical, radiologic, surgical, and histopathologic findings are described.