Myopia/heavy eye syndrome: a rare cause of horizontal diplopia

A 30-year-old woman with myopia (−8 diopters) developed binocular horizontal diplopia over a year. She had chronic migraine and no other symptoms. Ocular motility showed a comitant esotropia (20 diopters), and 2-diopter right hypertropia. MRI (figures 1 and 2) showed features of heavy eye syndrome,1 which is associated with superotemporal prolapse of the posterior globe, degeneration of lateral rectus–superior rectus band, and displacement of the lateral rectus downward.2 The abduction failure may be confused with a sixth nerve palsy. Our patient was treated with prisms with partial success, which along with strabismus correction are the treatment options.