Dissociated horizontal deviation and accommodative esotropia: treatment options when an eso- and an exodeviation co-exist.

Dissociated strabismus includes movements in the vertical, horizontal, and torsional axes. Dissociated vertical deviation (DVD) is an oversimplified label because it implies a purely vertical deviation. When the abducting component of the dissociated strabismus complex is prominent, the term dissociated horizontal deviation (DHD) is used. We present six patients with accommodative esotropia who developed prominent DHD. Only two patients have a prior history of congenital esotropia. Latent nystagmus was observed in five of the patients. With the combination of DHD and esotropia, an esodeviation during active fixation may become an exodeviation when the patient is visually inattentive. Five patients required surgery for DHD. Four options are used and discussed. DHD can be treated alone with lateral rectus muscle recession. DHD can be treated as above, but combined with medial rectus muscle recessions or posterior fixation sutures to simultaneously treat the esotropia. The esotropia can be treated alone, possibly with a reduced surgical dosage. If the patient varies from an esodeviation to an exodeviation, but is straight much of the day, observation without surgical therapy may be advisable. Just as a hypotropia can have an overlying DVD, an esotropia can have an overlying DHD. This combination may masquerade as variable angle esotropia or may present as an esodeviation when the patient is visually attentive and an exodeviation when the patient is visually inattentive.